Pub Date : 2023-09-01DOI: 10.3724/SP.J.1123.2023.03015
Jie DU, Peng-Chao Sun, Meng-Lu Zhang, Ze-Te Lian, Feng-Gang Yuan, Gang Wang
<p><p>Most polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants, have strong carcinogenicity, teratogenicity, and mutagenicity, and pose serious threats to the ecological environment and human health. Owing to the complexity of the matrix and low PAH content of environmental samples, separating and enriching PAHs in environmental samples is necessary prior to their detection. Solid-phase microextraction (SPME) technology is commonly used to detect PAHs owing to its advantages of simple operation, online connection with other instruments, low solvent usage, and integrability of sampling separation, enrichment, and desorption. The extraction coating is the core of this technology, and the type and thickness of the coating are important factors affecting the sensitivity and accuracy of the analysis. Common commercial extraction coatings include polydimethylsiloxane and quartz fiber; however, these materials have a number of disadvantages, such as poor thermal stability and high cost. Several methods, including electrochemical, sol-gel, molecular imprinting, and other coating methods, have been developed to prepare SPME coatings. Electrochemical methods have attracted considerable attention because of their simplicity, short duration, and high coating stability. In the development of an electrochemical method, the selection of the conductive polymer is of particular importance. Polypyrroles (Ppy) are easily synthesized and have numerous advantages, such as good conductivity and stable chemical properties. Thus, their use as a substrate material for SPME coatings is beneficial for improving the overall stability of the coating. Copolymerization with other polymers can enhance the adsorption performance of such coatings via synergistic effects. When doped with inorganic materials with high thermal stability, the composite coating can exhibit high temperature resistance. In this study, a porous boron nitride-doped Ppy-2,3,3-trimethylindole (Ppy/P2,3,3-TMe@In/BN) composite was prepared as a new SPME copolymer coating to detect three PAHs: naphthalene (NAP), acenaphthene (ANY), and fluorene (FLU). Scanning electron microscopy, thermal stability analysis, Fourier transform infrared spectroscopy, and other techniques were used to characterize the Ppy/P2,3,3-TMe@In/BN composite coating. The results showed that the coating featured a large number of porous and wrinkled dendritic structures, which increased the specific surface area of the composite coating and enabled the extensive enrichment of the three PAHs. When the sample inlet temperature of the chromatograph is 320 ℃, the chromatographic baseline of the coating is basically stable. Compared with commercial coatings, the prepared coating had better thermal stability. The coating formed stable intermolecular forces with the three PAHs owing to its numerous carbon-carbon double bonds (C=C), hydrogen bonds, and other structures, thereby achieving excellent enrichment of the targ
{"title":"[Preparation of porous boron nitride-doped polypyrrole-2,3,3-trimethylindole solid-phase microextraction coating for polycyclic aromatic hydrocarbon detection].","authors":"Jie DU, Peng-Chao Sun, Meng-Lu Zhang, Ze-Te Lian, Feng-Gang Yuan, Gang Wang","doi":"10.3724/SP.J.1123.2023.03015","DOIUrl":"10.3724/SP.J.1123.2023.03015","url":null,"abstract":"<p><p>Most polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants, have strong carcinogenicity, teratogenicity, and mutagenicity, and pose serious threats to the ecological environment and human health. Owing to the complexity of the matrix and low PAH content of environmental samples, separating and enriching PAHs in environmental samples is necessary prior to their detection. Solid-phase microextraction (SPME) technology is commonly used to detect PAHs owing to its advantages of simple operation, online connection with other instruments, low solvent usage, and integrability of sampling separation, enrichment, and desorption. The extraction coating is the core of this technology, and the type and thickness of the coating are important factors affecting the sensitivity and accuracy of the analysis. Common commercial extraction coatings include polydimethylsiloxane and quartz fiber; however, these materials have a number of disadvantages, such as poor thermal stability and high cost. Several methods, including electrochemical, sol-gel, molecular imprinting, and other coating methods, have been developed to prepare SPME coatings. Electrochemical methods have attracted considerable attention because of their simplicity, short duration, and high coating stability. In the development of an electrochemical method, the selection of the conductive polymer is of particular importance. Polypyrroles (Ppy) are easily synthesized and have numerous advantages, such as good conductivity and stable chemical properties. Thus, their use as a substrate material for SPME coatings is beneficial for improving the overall stability of the coating. Copolymerization with other polymers can enhance the adsorption performance of such coatings via synergistic effects. When doped with inorganic materials with high thermal stability, the composite coating can exhibit high temperature resistance. In this study, a porous boron nitride-doped Ppy-2,3,3-trimethylindole (Ppy/P2,3,3-TMe@In/BN) composite was prepared as a new SPME copolymer coating to detect three PAHs: naphthalene (NAP), acenaphthene (ANY), and fluorene (FLU). Scanning electron microscopy, thermal stability analysis, Fourier transform infrared spectroscopy, and other techniques were used to characterize the Ppy/P2,3,3-TMe@In/BN composite coating. The results showed that the coating featured a large number of porous and wrinkled dendritic structures, which increased the specific surface area of the composite coating and enabled the extensive enrichment of the three PAHs. When the sample inlet temperature of the chromatograph is 320 ℃, the chromatographic baseline of the coating is basically stable. Compared with commercial coatings, the prepared coating had better thermal stability. The coating formed stable intermolecular forces with the three PAHs owing to its numerous carbon-carbon double bonds (C=C), hydrogen bonds, and other structures, thereby achieving excellent enrichment of the targ","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 9","pages":"789-798"},"PeriodicalIF":1.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10507528/pdf/cjc-41-09-789.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10245625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>The quality and safety of agricultural products are strongly related to human livelihood. Thus, the government and consumers have recently paid increased attention to the quality and safety of agricultural products. The development of efficient, rapid, and sensitive analytical methods for detecting pesticides, veterinary drugs, heavy metals, mycotoxins, and environmental pollutants in agricultural products is of great significance. Owing to the complexity of many sample matrices and the low concentration of pollutants in a typical sample, appropriate sample pretreatment steps are necessary to enrich pollutants in agricultural products. Solid-phase extraction (SPE) is the most widely used sample pretreatment technology; in this technique, the adsorbent generally determines the selectivity and efficiency of the extraction process. An increasing number of novel materials have been used as SPE adsorbents. The extraction efficiency, extraction selectivity, and analytical throughput of SPE could be greatly improved by combining these novel materials with various extraction modes (e. g., solid-phase microextraction, dispersed SPE, and magnetic SPE (MSPE)) during sample preparation. Because of their large specific surface area and high affinity toward target analytes, nanomaterials are often used as SPE adsorbents, thereby greatly improving the selectivity and sensitivity of the analytical technology. More importantly, these materials have become a priority area of research on preconcentration technologies for trace compounds in agricultural products. This paper summarizes the adsorption characteristics of several new nanomaterials, including magnetic materials, carbon-based materials, metal nanomaterials (MNs), metal oxide nanomaterials (MONs), metal organic frameworks (MOFs), and covalent organic frameworks (COFs). These nanomaterials present numerous advantages, such as large specific surface areas, high adsorption capacities, and tailorable structural designs. MSPE employs magnetic materials as sorbents to afford fast dispersion and efficient recycling when applied to complex sample matrices under an external magnetic field. The use of MSPE can avoid several typical problems associated with SPE such as poor adsorbent packing and high pressure, thereby greatly simplifying the pretreatment process and providing a high flux for sample analysis. Carbon-based materials are powdered or bulk nonmetallic solid materials with carbon as the main component; carbon and nitrogen materials, mesoporous carbon, carbon nanotubes, and graphene are some examples of these materials. These materials provide large specific surface areas, abundant pore structures, good thermal stability, high mechanical strength and adsorption capacity, and controllable morphology. Pure and modified carbon nanomaterials have been successfully used to purify target analytes from agricultural products. Given their unique physical and chemical properties, MNs and MONs have attracted sig
{"title":"[Progress in the application of novel nano-materials to the safety analysis of agricultural products].","authors":"Ran-Feng Zhou, Hui-Xian Zhang, Xiao-Li Yin, Xi-Tian Peng","doi":"10.3724/SP.J.1123.2022.09010","DOIUrl":"10.3724/SP.J.1123.2022.09010","url":null,"abstract":"<p><p>The quality and safety of agricultural products are strongly related to human livelihood. Thus, the government and consumers have recently paid increased attention to the quality and safety of agricultural products. The development of efficient, rapid, and sensitive analytical methods for detecting pesticides, veterinary drugs, heavy metals, mycotoxins, and environmental pollutants in agricultural products is of great significance. Owing to the complexity of many sample matrices and the low concentration of pollutants in a typical sample, appropriate sample pretreatment steps are necessary to enrich pollutants in agricultural products. Solid-phase extraction (SPE) is the most widely used sample pretreatment technology; in this technique, the adsorbent generally determines the selectivity and efficiency of the extraction process. An increasing number of novel materials have been used as SPE adsorbents. The extraction efficiency, extraction selectivity, and analytical throughput of SPE could be greatly improved by combining these novel materials with various extraction modes (e. g., solid-phase microextraction, dispersed SPE, and magnetic SPE (MSPE)) during sample preparation. Because of their large specific surface area and high affinity toward target analytes, nanomaterials are often used as SPE adsorbents, thereby greatly improving the selectivity and sensitivity of the analytical technology. More importantly, these materials have become a priority area of research on preconcentration technologies for trace compounds in agricultural products. This paper summarizes the adsorption characteristics of several new nanomaterials, including magnetic materials, carbon-based materials, metal nanomaterials (MNs), metal oxide nanomaterials (MONs), metal organic frameworks (MOFs), and covalent organic frameworks (COFs). These nanomaterials present numerous advantages, such as large specific surface areas, high adsorption capacities, and tailorable structural designs. MSPE employs magnetic materials as sorbents to afford fast dispersion and efficient recycling when applied to complex sample matrices under an external magnetic field. The use of MSPE can avoid several typical problems associated with SPE such as poor adsorbent packing and high pressure, thereby greatly simplifying the pretreatment process and providing a high flux for sample analysis. Carbon-based materials are powdered or bulk nonmetallic solid materials with carbon as the main component; carbon and nitrogen materials, mesoporous carbon, carbon nanotubes, and graphene are some examples of these materials. These materials provide large specific surface areas, abundant pore structures, good thermal stability, high mechanical strength and adsorption capacity, and controllable morphology. Pure and modified carbon nanomaterials have been successfully used to purify target analytes from agricultural products. Given their unique physical and chemical properties, MNs and MONs have attracted sig","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 9","pages":"731-741"},"PeriodicalIF":1.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10507529/pdf/cjc-41-09-731.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10245622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>Malachite green (MG) and its metabolite, leucomalachite green (LMG), exert toxic effects on the human body. The use of these dyes is illegal, but they are still detected in aquatic products. Freshwater fish are aquatic products with the high non-qualified rates. Therefore, the sensitive screening of MG and LMG in freshwater fish is of great importance to ensure the safety of aquatic products. Owing to the low contents of MG and LMG in fish and the complex matrix of actual samples, sample preparation is required before detection to purify impurities and enrich the target compounds. Graphite carbon nitride (GCN), a polymer material composed of C, N, and H, has good chemical and thermal stability, a large specific surface area, and a large number of active sites. It has a wide range of application prospects in adsorption and can be used in food safety testing when compounded with Fe<sub>3</sub>O<sub>4</sub> to form magnetic graphite carbon nitride (MGCN). In this study, sulfonated magnetic graphite carbon nitride (S-MGCN) was prepared by further functionalizing MGCN with sulfonic acid. After characterization by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM), a magnetic solid-phase extraction (MSPE) method based on S-MGCN was established to extract MG and LMG from freshwater fish. The targets were screened using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Following sulfonic acid functionalization, S-MGCN showed increased electrostatic interactions based on the MGCN adsorption mechanism, which includes hydrogen bonds and <i>π-π</i> interactions; thus, its adsorption efficiency was significantly improved. The matrix effects were -42.21% and -33.77% before functionalization, -11.40% and -7.84% after functionalization, thus confirming that S-MGCN has significant matrix removal ability. Given that S-MGCN demonstrated excellent efficiency as an MSPE adsorbent, the adsorption conditions for S-MGCN were optimized. The optimal conditions were as follows: adsorbent dosage, 15 mg; adsorption time, 2 min; solution pH, 5; and ionic strength, not adjusted. Under these conditions, the adsorption efficiency of S-MGCN could reach 94.2%. Different organic solvents were used to elute adsorbed MG and LMG, and the desorption efficiency peaked when 1%(v/v) ammonia acetonitrile was used as the elution solvent. The elution volume was also optimized, and a maximum desorption efficiency of 93.2% was obtained when 1 mL of 1%(v/v) ammonia acetonitrile was added to S-MGCN. The limits of detection (LODs) and quantification (LOQs) of the two targets were determined at signal-to-noise ratios (<i>S/N</i>) of 3 and 10, respectively. The LODs and LOQs were 0.075 μg/kg and 0.25 μg/kg, respectively. The linear ranges of the two target compounds were 0.25-20.0 μg/kg with correlation coefficients (<i>r</i>) greater than 0.998. To assess accuracy and precision, we prepared
{"title":"[Sulfonated magnetic graphite carbon nitride solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry for screening malachite green and leucomalachite green in freshwater fish].","authors":"Er-Qiong Meng, Qi-Xun Nian, Feng Li, Qiu-Ping Zhang, Qian Xu, Chun-Min Wang","doi":"10.3724/SP.J.1123.2022.12009","DOIUrl":"https://doi.org/10.3724/SP.J.1123.2022.12009","url":null,"abstract":"<p><p>Malachite green (MG) and its metabolite, leucomalachite green (LMG), exert toxic effects on the human body. The use of these dyes is illegal, but they are still detected in aquatic products. Freshwater fish are aquatic products with the high non-qualified rates. Therefore, the sensitive screening of MG and LMG in freshwater fish is of great importance to ensure the safety of aquatic products. Owing to the low contents of MG and LMG in fish and the complex matrix of actual samples, sample preparation is required before detection to purify impurities and enrich the target compounds. Graphite carbon nitride (GCN), a polymer material composed of C, N, and H, has good chemical and thermal stability, a large specific surface area, and a large number of active sites. It has a wide range of application prospects in adsorption and can be used in food safety testing when compounded with Fe<sub>3</sub>O<sub>4</sub> to form magnetic graphite carbon nitride (MGCN). In this study, sulfonated magnetic graphite carbon nitride (S-MGCN) was prepared by further functionalizing MGCN with sulfonic acid. After characterization by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM), a magnetic solid-phase extraction (MSPE) method based on S-MGCN was established to extract MG and LMG from freshwater fish. The targets were screened using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Following sulfonic acid functionalization, S-MGCN showed increased electrostatic interactions based on the MGCN adsorption mechanism, which includes hydrogen bonds and <i>π-π</i> interactions; thus, its adsorption efficiency was significantly improved. The matrix effects were -42.21% and -33.77% before functionalization, -11.40% and -7.84% after functionalization, thus confirming that S-MGCN has significant matrix removal ability. Given that S-MGCN demonstrated excellent efficiency as an MSPE adsorbent, the adsorption conditions for S-MGCN were optimized. The optimal conditions were as follows: adsorbent dosage, 15 mg; adsorption time, 2 min; solution pH, 5; and ionic strength, not adjusted. Under these conditions, the adsorption efficiency of S-MGCN could reach 94.2%. Different organic solvents were used to elute adsorbed MG and LMG, and the desorption efficiency peaked when 1%(v/v) ammonia acetonitrile was used as the elution solvent. The elution volume was also optimized, and a maximum desorption efficiency of 93.2% was obtained when 1 mL of 1%(v/v) ammonia acetonitrile was added to S-MGCN. The limits of detection (LODs) and quantification (LOQs) of the two targets were determined at signal-to-noise ratios (<i>S/N</i>) of 3 and 10, respectively. The LODs and LOQs were 0.075 μg/kg and 0.25 μg/kg, respectively. The linear ranges of the two target compounds were 0.25-20.0 μg/kg with correlation coefficients (<i>r</i>) greater than 0.998. To assess accuracy and precision, we prepared","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"673-682"},"PeriodicalIF":0.7,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398829/pdf/cjc-41-08-673.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9958855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.3724/SP.J.1123.2023.03005
Wei Liu, Dong-Xue Jia, Wen-Hui Lian, Yu Zhao
Molecularly imprinted polymers have received wide attention from various fields owing to their pre-designable, recognition ability, and practicality. However, the disadvantages of the traditional embedding method, which include a slow recognition rate, uneven site recognition, low binding capacity, and incomplete template molecule elution, limit the development of molecular imprinting technology. Surface molecular imprinting techniques have been developed to effectively solve these problems, and different materials are used as carriers in the synthesis of molecularly imprinted polymers. Metal-organic frameworks (MOFs) show great potential as carriers. Because of their high porosity and specific surface area, MOFs can provide a large number of active sites for molecular imprinting, which can improve their detection sensitivity. The variable metal centers and organic ligands of MOF materials can also lead to multiple structures and functions. Numerous types of MOF materials have been synthesized, and the properties of these materials can be tailored by adjusting their pore size and introducing functional groups. MOFs and molecular imprinting technology can be combined to take full advantage of the specific adsorption of molecular imprinting technology and the large specific surface area and multiple active sites of MOFs, thereby expanding the application range of the resulting materials. In this paper, five aspects of the concept of MOF functionalization are discussed: introduction of special ligands, regulation of metal central sites, formation of MOF complexes, derivatization of MOFs, and sacrificial MOFs. The applications of MOF-based molecularly imprinted materials in catalysis, sample pretreatment, drug carriers, fluorescence sensors, and electrochemical sensors are also reviewed. Finally, the existing problems and future development of MOF-based molecularly imprinted materials are discussed and prospected.
{"title":"[Recent advances in the applications of metal-organic frameworks-based molecularly imprinted materials].","authors":"Wei Liu, Dong-Xue Jia, Wen-Hui Lian, Yu Zhao","doi":"10.3724/SP.J.1123.2023.03005","DOIUrl":"https://doi.org/10.3724/SP.J.1123.2023.03005","url":null,"abstract":"<p><p>Molecularly imprinted polymers have received wide attention from various fields owing to their pre-designable, recognition ability, and practicality. However, the disadvantages of the traditional embedding method, which include a slow recognition rate, uneven site recognition, low binding capacity, and incomplete template molecule elution, limit the development of molecular imprinting technology. Surface molecular imprinting techniques have been developed to effectively solve these problems, and different materials are used as carriers in the synthesis of molecularly imprinted polymers. Metal-organic frameworks (MOFs) show great potential as carriers. Because of their high porosity and specific surface area, MOFs can provide a large number of active sites for molecular imprinting, which can improve their detection sensitivity. The variable metal centers and organic ligands of MOF materials can also lead to multiple structures and functions. Numerous types of MOF materials have been synthesized, and the properties of these materials can be tailored by adjusting their pore size and introducing functional groups. MOFs and molecular imprinting technology can be combined to take full advantage of the specific adsorption of molecular imprinting technology and the large specific surface area and multiple active sites of MOFs, thereby expanding the application range of the resulting materials. In this paper, five aspects of the concept of MOF functionalization are discussed: introduction of special ligands, regulation of metal central sites, formation of MOF complexes, derivatization of MOFs, and sacrificial MOFs. The applications of MOF-based molecularly imprinted materials in catalysis, sample pretreatment, drug carriers, fluorescence sensors, and electrochemical sensors are also reviewed. Finally, the existing problems and future development of MOF-based molecularly imprinted materials are discussed and prospected.</p>","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"651-661"},"PeriodicalIF":0.7,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398830/pdf/cjc-41-08-651.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9958859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.3724/SP.J.1123.2023.03007
Ping-Ping Wu, Ren-Yi Lin, Li-Ying Huang
<p><p><i>Dendrobium officinale</i> (<i>D. officinale</i>) and <i>Anoectochilus roxburghii</i> (<i>A. roxburghii</i>) are precious raw materials for traditional Chinese medicine. The growing demand for <i>D. officinale</i> and <i>A. roxburghii</i> cannot be met by current production techniques. Hence, the widespread artificial cultivation of <i>D. officinale</i> and <i>A. roxburghii</i> using substantial amounts of plant growth regulators (PGRs) has emerged. The excessive use of PGRs not only affects the quality and efficacy of medicinal materials but also causes a series of safety issues. Therefore, expanding research on residual PGRs in valuable Chinese medicinal materials is important to avoid the health hazards caused by these substances. Unfortunately, the identification of PGRs is challenging because of their trace and complex matrices. High performance liquid chromatography (HPLC) has become one of the mainstream analytical methods for PGR determination. An important consideration in the application of this technique to the detection of trace acidic PGRs is how to improve its accuracy and sensitivity. Three-phase hollow fiber liquid phase microextraction (3P-HF-LPME) has the advantages of a high enrichment factor, complex sample purification ability, low reagent consumption, low cost, and easy integration with chromatographic systems. Thus, the 3P-HF-LPME method overcomes the many shortcomings of traditional sample pretreatment methods. In this study, a novel, simple, and effective analytical method based on 3P-HF-LPME combined with HPLC was developed to extract, purify, enrich, and detect three trace acidic PGRs (indole-3-acetic acid, naphthyl acetic acid and indolebutyric acid) in <i>D. officinale</i> and <i>A. roxburghii</i>. The chromatographic separation conditions and 3P-HF-LPME model parameters were systematically optimized for this purpose. First, the sample solution was prepared by ultrasonication and low-temperature standing, and then adjusted to pH 3.0 using dilute hydrochloric acid. The sample solution (10 mL) and NaCl (1.50 g) were stored in a 15 mL brown extraction bottle with a built-in magnetic stirrer. Next, 30 μL of NaOH solution (pH 11.0) as the inner phase solution was injected into the inner cavity of a hollow fiber tube, which was subsequently sealed at both ends. The hollow fiber tube was soaked in <i>n</i>-octanol for 5 min and dried naturally to remove excess extraction solvent from its surface. Finally, the fiber tube was placed in a brown extraction bottle and stirred using a thermostatic magnetic stirrer at 40 ℃ and 1600 r/min for 2 h. After extraction, the three target analytes were separated on a Welch Ultimate XB-C<sub>18</sub> column (250 mm×4.6 mm, 5 μm) under isocratic elution conditions using acetic acid aqueous solution and methanol (45∶55, v/v) as the eluent. The results indicated that the three PGRs showed good linearity in the range of 0.5-100.0 μg/L (coefficients of determination (<i>r</i><sup>2</sup>
{"title":"[Determination of three plant growth regulators in <i>Dendrobium officinale</i> and <i>Anoectochilus roxburghii</i> by three-phase hollow fiber liquid phase microextraction- high performance liquid chromatography].","authors":"Ping-Ping Wu, Ren-Yi Lin, Li-Ying Huang","doi":"10.3724/SP.J.1123.2023.03007","DOIUrl":"10.3724/SP.J.1123.2023.03007","url":null,"abstract":"<p><p><i>Dendrobium officinale</i> (<i>D. officinale</i>) and <i>Anoectochilus roxburghii</i> (<i>A. roxburghii</i>) are precious raw materials for traditional Chinese medicine. The growing demand for <i>D. officinale</i> and <i>A. roxburghii</i> cannot be met by current production techniques. Hence, the widespread artificial cultivation of <i>D. officinale</i> and <i>A. roxburghii</i> using substantial amounts of plant growth regulators (PGRs) has emerged. The excessive use of PGRs not only affects the quality and efficacy of medicinal materials but also causes a series of safety issues. Therefore, expanding research on residual PGRs in valuable Chinese medicinal materials is important to avoid the health hazards caused by these substances. Unfortunately, the identification of PGRs is challenging because of their trace and complex matrices. High performance liquid chromatography (HPLC) has become one of the mainstream analytical methods for PGR determination. An important consideration in the application of this technique to the detection of trace acidic PGRs is how to improve its accuracy and sensitivity. Three-phase hollow fiber liquid phase microextraction (3P-HF-LPME) has the advantages of a high enrichment factor, complex sample purification ability, low reagent consumption, low cost, and easy integration with chromatographic systems. Thus, the 3P-HF-LPME method overcomes the many shortcomings of traditional sample pretreatment methods. In this study, a novel, simple, and effective analytical method based on 3P-HF-LPME combined with HPLC was developed to extract, purify, enrich, and detect three trace acidic PGRs (indole-3-acetic acid, naphthyl acetic acid and indolebutyric acid) in <i>D. officinale</i> and <i>A. roxburghii</i>. The chromatographic separation conditions and 3P-HF-LPME model parameters were systematically optimized for this purpose. First, the sample solution was prepared by ultrasonication and low-temperature standing, and then adjusted to pH 3.0 using dilute hydrochloric acid. The sample solution (10 mL) and NaCl (1.50 g) were stored in a 15 mL brown extraction bottle with a built-in magnetic stirrer. Next, 30 μL of NaOH solution (pH 11.0) as the inner phase solution was injected into the inner cavity of a hollow fiber tube, which was subsequently sealed at both ends. The hollow fiber tube was soaked in <i>n</i>-octanol for 5 min and dried naturally to remove excess extraction solvent from its surface. Finally, the fiber tube was placed in a brown extraction bottle and stirred using a thermostatic magnetic stirrer at 40 ℃ and 1600 r/min for 2 h. After extraction, the three target analytes were separated on a Welch Ultimate XB-C<sub>18</sub> column (250 mm×4.6 mm, 5 μm) under isocratic elution conditions using acetic acid aqueous solution and methanol (45∶55, v/v) as the eluent. The results indicated that the three PGRs showed good linearity in the range of 0.5-100.0 μg/L (coefficients of determination (<i>r</i><sup>2</sup>","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"683-689"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398823/pdf/cjc-41-08-683.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10330713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.3724/SP.J.1123.2022.12025
Qin-Ling Cao, Xiao-Dan Zhao, Guo-Bin Shen, Zhu-Qin Wang, Hong-Yang Zhang, Min Zhang, Ping Hu
<p><p>Sophorolipids are secondary metabolites produced during fermentation by nonpathogenic yeasts. These molecules are amphiphilic and consist of a hydrophilic sophora sugar moiety and a hydrophobic hydroxylated fatty acid. Based on their degree of esterification, sophorolipids can be divided into the acid and lactone types. Sophorolipids are highly promising biosurfactants with good antibacterial, antiviral, and other biological activities. Moreover, they are characterized by mildness, low toxicity, and environmental friendliness. However, their composition is quite complex, and effective methods for their quality evaluation are lacking. Since sophorolipids do not absorb ultraviolet (UV) light, common UV detectors are unsuitable for fingerprint establishment. In this study, we first selected a charged aerosol detector (CAD) to establish the ultra-high performance liquid chromatography (UHPLC) fingerprint of sophorolipids. The detector had high sensitivity, good reproducibility, and excellent suitability for the detection of substances with no or weak ultraviolet absorption. We then evaluated the similarities between 17 batches of sophorolipid samples. The samples were extracted by ultrasound for 10 min in 80% ethanol aqueous solution at a liquid-solid ratio of 10∶1 (mL/g) and then separated on a Thermo Fisher Scientific Hypersil Gold chromatographic column (150 mm×2.1 mm, 1.9 μm). Separation was performed using acetonitrile-0.01% (v/v) formic acid aqueous solution as the mobile phase via gradient elution. The flow rate was 0.2 mL/min, and the column temperature was 40 ℃. The CAD was used under the following conditions: power function of 1.0, data rate of 5 Hz, filter constant of 3.6, and evaporation temperature of 45 ℃. The chromatograms and retention times of the sophorolipids were compared, and 16 common peaks with strong responses, good resolutions, and stable retention times were selected as characteristic peaks. Oleic acid was chosen as the reference peak because it achieved good separation and a strong chromatographic response in all batches of samples. UHPLC-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was used to identify chromatographic peaks in the sophorolipid fingerprints. The results were combined with the retention time rule of the sophorolipids, leading to their identification based on matching with the results of the primary database, the precise relative molecular mass and fragmentation rule of secondary fragments, a self-built database, and the PubChem database. Sixteen compounds were identified, including eight acid sophorolipids, six lactone sophorolipids, and two aliphatic acids. The results of precision, repeatability, and 24 h stability tests indicated that the relative standard deviations (RSDs) of the retention times and peak areas of the 15 characteristic peaks relative to the control peak (oleic acid) were less than 3.0% (<i>n</i>=6). Seventeen batches of sophorolipid samples were analyzed, and the simi
{"title":"[Fingerprint of sophorolipids based on ultra-high performance liquid chromatography-charged aerosol detection].","authors":"Qin-Ling Cao, Xiao-Dan Zhao, Guo-Bin Shen, Zhu-Qin Wang, Hong-Yang Zhang, Min Zhang, Ping Hu","doi":"10.3724/SP.J.1123.2022.12025","DOIUrl":"10.3724/SP.J.1123.2022.12025","url":null,"abstract":"<p><p>Sophorolipids are secondary metabolites produced during fermentation by nonpathogenic yeasts. These molecules are amphiphilic and consist of a hydrophilic sophora sugar moiety and a hydrophobic hydroxylated fatty acid. Based on their degree of esterification, sophorolipids can be divided into the acid and lactone types. Sophorolipids are highly promising biosurfactants with good antibacterial, antiviral, and other biological activities. Moreover, they are characterized by mildness, low toxicity, and environmental friendliness. However, their composition is quite complex, and effective methods for their quality evaluation are lacking. Since sophorolipids do not absorb ultraviolet (UV) light, common UV detectors are unsuitable for fingerprint establishment. In this study, we first selected a charged aerosol detector (CAD) to establish the ultra-high performance liquid chromatography (UHPLC) fingerprint of sophorolipids. The detector had high sensitivity, good reproducibility, and excellent suitability for the detection of substances with no or weak ultraviolet absorption. We then evaluated the similarities between 17 batches of sophorolipid samples. The samples were extracted by ultrasound for 10 min in 80% ethanol aqueous solution at a liquid-solid ratio of 10∶1 (mL/g) and then separated on a Thermo Fisher Scientific Hypersil Gold chromatographic column (150 mm×2.1 mm, 1.9 μm). Separation was performed using acetonitrile-0.01% (v/v) formic acid aqueous solution as the mobile phase via gradient elution. The flow rate was 0.2 mL/min, and the column temperature was 40 ℃. The CAD was used under the following conditions: power function of 1.0, data rate of 5 Hz, filter constant of 3.6, and evaporation temperature of 45 ℃. The chromatograms and retention times of the sophorolipids were compared, and 16 common peaks with strong responses, good resolutions, and stable retention times were selected as characteristic peaks. Oleic acid was chosen as the reference peak because it achieved good separation and a strong chromatographic response in all batches of samples. UHPLC-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was used to identify chromatographic peaks in the sophorolipid fingerprints. The results were combined with the retention time rule of the sophorolipids, leading to their identification based on matching with the results of the primary database, the precise relative molecular mass and fragmentation rule of secondary fragments, a self-built database, and the PubChem database. Sixteen compounds were identified, including eight acid sophorolipids, six lactone sophorolipids, and two aliphatic acids. The results of precision, repeatability, and 24 h stability tests indicated that the relative standard deviations (RSDs) of the retention times and peak areas of the 15 characteristic peaks relative to the control peak (oleic acid) were less than 3.0% (<i>n</i>=6). Seventeen batches of sophorolipid samples were analyzed, and the simi","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"722-729"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398824/pdf/cjc-41-08-722.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9958861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.3724/SP.J.1123.2022.12004
Jian-Ying Huang, Ling Xia, Xiao-Hua Xiao, Gong-Ke Li
<p><p>Microchip electrophoresis is a separation technology that involves fluid manipulation in a microchip; the advantages of this technique include high separation efficiency, low sample consumption, and fast and easy multistep integration. Microchip electrophoresis has been widely used to rapidly separate and analyze complex samples in biology and medicine. In this paper, we review the research progress on microchip electrophoresis, explore the fabrication and separation modes of microchip materials, and discuss their applications in the detection and analysis of biological samples. Research on microchip materials can be mainly categorized into chip materials, channel modifications, electrode materials, and electrode integration methods. Microchip materials research involves the development of silicon, glass, polydimethylsiloxane and polymethyl methacrylate-based, and paper electrophoretic materials. Microchannel modification research primarily focuses on the dynamic and static modification methods of microchannels. Although chip materials and fabrication technologies have improved over the years, problems such as high manufacturing costs, long processing time, and short service lives continue to persist. These problems hinder the industrialization of microchip electrophoresis. At present, few static methods for the surface modification of polymer channels are available, and most of them involve a combination of physical adsorption and polymers. Therefore, developing efficient surface modification methods for polymer channels remains a necessary undertaking. In addition, both dynamic and static modifications require the introduction of other chemicals, which may not be conducive to the expansion of subsequent experiments. The materials commonly used in the development of electrodes and processing methods for electrode-microchip integration include gold, platinum, and silver. Microchip electrophoresis can be divided into two modes according to the uniformity of the electric field: uniform and non-uniform. The uniform electric field electrophoresis mode mainly involves micro free-flow electrophoresis and micro zone electrophoresis, including micro isoelectric focusing electrophoresis, micro isovelocity electrophoresis, and micro density gradient electrophoresis. The non-uniform electric field electrophoresis mode involves micro dielectric electrophoresis. Microchip electrophoresis is typically used in conjunction with conventional laboratory methods, such as optical, electrochemical, and mass spectrometry, to achieve the rapid and efficient separation and analysis of complex samples. However, the labeling required for most widely used laser-induced fluorescence technologies often involves a cumbersome organic synthesis process, and not all samples can be labeled, which limits the application scenarios of laser-induced fluorescence. The applications of unlabeled microchip electrophoresis-chemiluminescence/dielectrophoresis are also limited, and si
{"title":"[Advances in microchip electrophoresis for the separation and analysis of biological samples].","authors":"Jian-Ying Huang, Ling Xia, Xiao-Hua Xiao, Gong-Ke Li","doi":"10.3724/SP.J.1123.2022.12004","DOIUrl":"10.3724/SP.J.1123.2022.12004","url":null,"abstract":"<p><p>Microchip electrophoresis is a separation technology that involves fluid manipulation in a microchip; the advantages of this technique include high separation efficiency, low sample consumption, and fast and easy multistep integration. Microchip electrophoresis has been widely used to rapidly separate and analyze complex samples in biology and medicine. In this paper, we review the research progress on microchip electrophoresis, explore the fabrication and separation modes of microchip materials, and discuss their applications in the detection and analysis of biological samples. Research on microchip materials can be mainly categorized into chip materials, channel modifications, electrode materials, and electrode integration methods. Microchip materials research involves the development of silicon, glass, polydimethylsiloxane and polymethyl methacrylate-based, and paper electrophoretic materials. Microchannel modification research primarily focuses on the dynamic and static modification methods of microchannels. Although chip materials and fabrication technologies have improved over the years, problems such as high manufacturing costs, long processing time, and short service lives continue to persist. These problems hinder the industrialization of microchip electrophoresis. At present, few static methods for the surface modification of polymer channels are available, and most of them involve a combination of physical adsorption and polymers. Therefore, developing efficient surface modification methods for polymer channels remains a necessary undertaking. In addition, both dynamic and static modifications require the introduction of other chemicals, which may not be conducive to the expansion of subsequent experiments. The materials commonly used in the development of electrodes and processing methods for electrode-microchip integration include gold, platinum, and silver. Microchip electrophoresis can be divided into two modes according to the uniformity of the electric field: uniform and non-uniform. The uniform electric field electrophoresis mode mainly involves micro free-flow electrophoresis and micro zone electrophoresis, including micro isoelectric focusing electrophoresis, micro isovelocity electrophoresis, and micro density gradient electrophoresis. The non-uniform electric field electrophoresis mode involves micro dielectric electrophoresis. Microchip electrophoresis is typically used in conjunction with conventional laboratory methods, such as optical, electrochemical, and mass spectrometry, to achieve the rapid and efficient separation and analysis of complex samples. However, the labeling required for most widely used laser-induced fluorescence technologies often involves a cumbersome organic synthesis process, and not all samples can be labeled, which limits the application scenarios of laser-induced fluorescence. The applications of unlabeled microchip electrophoresis-chemiluminescence/dielectrophoresis are also limited, and si","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"641-650"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398827/pdf/cjc-41-08-641.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9958849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) have attracted significant attention because of their persistence, biotoxicity, bioaccumulation, and long-range migration. Given their worldwide detection in a variety of environmental matrices, concerns related to the high exposure risks of SCCPs and MCCPs to humans have grown. Thus, knowledge of the contamination patterns of SCCPs and MCCPs and their distribution characteristics in the vivo exposure of humans is of great importance. However, little information is available on the contamination of SCCPs and MCCPs in human blood/plasma/serum, mainly because of the difficulty of sample preparation and quantitative analysis. In this study, a new blood sample pretreatment method based on Percoll discontinuous density gradient centrifugation was developed to separate plasma, red blood cells, white blood cells, and platelets from human whole blood. A series of Percoll sodium chloride buffer solutions with mass concentrations of 1.095, 1.077, and 1.060 g/mL were placed in a centrifuge tube from top to bottom to establish discontinuous density gradients. The dosage for each density gradient was 1.5 mL. Human whole blood samples mixed with 0.85% sodium chloride aqueous solution were then added to the top layer of the Percoll sodium chloride solution. After centrifugation, the whole blood was separated into four components. The plasma was located at the top layer of the centrifuge tube, whereas the platelets, white blood cells, and red blood cells were retained at the junction of the various Percoll sodium chloride solutions. The sampling volume of human whole blood and incubation time were optimized, and results indicated that an excessively long incubation time could lead to hemolysis, resulting in a decrease in the recoveries of SCCPs and MCCPs. Therefore, a sampling volume of 1.5 mL and incubation time of 10 min at 4 ℃ were adopted. The cells of the blood components were further broken and extracted by ultrasonic pretreatment, followed by multilayer silica gel column chromatography for lipid removal. The use of 80 mL of <i>n</i>-hexane-dichloromethane (1∶1, v/v) and 50 mL of dichloromethane as the elution solvents (collected together) for the gel column separated the SCCPs and MCCPs from the lipid molecules in the blood samples. Gas chromatography-electron capture negative ion-low resolution mass spectrometry (GC-ECNI-LRMS) was used to determine the SCCPs and MCCPs. Quantification using the corrected total response factor with degrees of chlorination was achieved with linear corrections (<i>R</i><sup>2</sup>=0.912 and 0.929 for the SCCPs and MCCPs, respectively). The method detection limits (MDLs) for the SCCPs and MCCPs were 1.57 and 8.29 ng/g wet weight (ww, <i>n</i>=7), respectively. The extraction internal standard recoveries were 67.0%-126.6% for the SCCPs and 69.5%-120.5% for the MCCPs. The developed method was applied to determine SCCPs and MCCPs in actual human whole blood s
{"title":"[Determination of short- and medium-chain chlorinated paraffins in different components of human blood using gas chromatography-electron capture negative ion-low resolution mass spectrometry].","authors":"Shuang Yu, Yuan Gao, Xiu-Hua Zhu, Ning-Bo Geng, Yu-Bing Dai, Jian-Yao Hong, Ji-Ping Chen","doi":"10.3724/SP.J.1123.2022.11012","DOIUrl":"10.3724/SP.J.1123.2022.11012","url":null,"abstract":"<p><p>Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) have attracted significant attention because of their persistence, biotoxicity, bioaccumulation, and long-range migration. Given their worldwide detection in a variety of environmental matrices, concerns related to the high exposure risks of SCCPs and MCCPs to humans have grown. Thus, knowledge of the contamination patterns of SCCPs and MCCPs and their distribution characteristics in the vivo exposure of humans is of great importance. However, little information is available on the contamination of SCCPs and MCCPs in human blood/plasma/serum, mainly because of the difficulty of sample preparation and quantitative analysis. In this study, a new blood sample pretreatment method based on Percoll discontinuous density gradient centrifugation was developed to separate plasma, red blood cells, white blood cells, and platelets from human whole blood. A series of Percoll sodium chloride buffer solutions with mass concentrations of 1.095, 1.077, and 1.060 g/mL were placed in a centrifuge tube from top to bottom to establish discontinuous density gradients. The dosage for each density gradient was 1.5 mL. Human whole blood samples mixed with 0.85% sodium chloride aqueous solution were then added to the top layer of the Percoll sodium chloride solution. After centrifugation, the whole blood was separated into four components. The plasma was located at the top layer of the centrifuge tube, whereas the platelets, white blood cells, and red blood cells were retained at the junction of the various Percoll sodium chloride solutions. The sampling volume of human whole blood and incubation time were optimized, and results indicated that an excessively long incubation time could lead to hemolysis, resulting in a decrease in the recoveries of SCCPs and MCCPs. Therefore, a sampling volume of 1.5 mL and incubation time of 10 min at 4 ℃ were adopted. The cells of the blood components were further broken and extracted by ultrasonic pretreatment, followed by multilayer silica gel column chromatography for lipid removal. The use of 80 mL of <i>n</i>-hexane-dichloromethane (1∶1, v/v) and 50 mL of dichloromethane as the elution solvents (collected together) for the gel column separated the SCCPs and MCCPs from the lipid molecules in the blood samples. Gas chromatography-electron capture negative ion-low resolution mass spectrometry (GC-ECNI-LRMS) was used to determine the SCCPs and MCCPs. Quantification using the corrected total response factor with degrees of chlorination was achieved with linear corrections (<i>R</i><sup>2</sup>=0.912 and 0.929 for the SCCPs and MCCPs, respectively). The method detection limits (MDLs) for the SCCPs and MCCPs were 1.57 and 8.29 ng/g wet weight (ww, <i>n</i>=7), respectively. The extraction internal standard recoveries were 67.0%-126.6% for the SCCPs and 69.5%-120.5% for the MCCPs. The developed method was applied to determine SCCPs and MCCPs in actual human whole blood s","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"698-706"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398826/pdf/cjc-41-08-698.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9958858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p><p>Fraxini Cortex is a traditional Chinese herbal medicine that has been used for thousands of years to treat dampness-heat diarrhea, dysentery, red or white vaginal discharge, painful swelling or redness of the eyes, and nebula. It contains various chemical components, including coumarins, iridoids, phenolic acids, and flavonoids. Coumarins are important active ingredients in Fraxini Cortex and have antibacterial, anti-inflammatory, antioxidant, antitumor, and antiviral activities. Aesculin and aesculetin are two major coumarin components of Fraxini Cortex that are widely used in its quality evaluation. Previous HPLC methods for determination of aesculin and aesculetin present several limitations, such as long analysis times and high solvent and reference compound consumption. In this study, a rapid, eco-friendly and cost saving HPLC method for the determination of aesculin and aesculetin in Fraxini Cortex was established by using the core-shell column and equal absorption wavelength (EAW). Different factors influencing the extraction process, such as the extraction solvent, temperature, and time, were assessed to obtain the optimal extraction conditions. The results showed that Fraxini Cortex samples could be well extracted by ultrasonic extraction for 5 min with a 25% ethanol aqueous solution. A core-shell column was used, and different mobile phases and flow rates were investigated to obtain the best rapid-HPLC separation conditions. The optimized HPLC conditions were as follows: a Poroshell 120 EC-C<sub>18</sub> column (50 mm×4.6 mm, 2.7 μm), acetonitrile-0.1% formic acid aqueous solution (6∶94, v/v) as the eluent, a flow rate of 1.5 mL/min, and a column temperature of 25 ℃. The EAW of aesculin and aesculetin was a key factor in their determination using a single reference compound. EAW selection was performed in two steps. First, the UV spectra of two equimolar concentrations of the reference compounds (aesculin and aesculetin) were compared to determine the EAW of the two analytes. The EAW results were then verified by the HPLC analysis of the reference compound solutions. The final EAW of aesculin and aesculetin was 341 nm. The determination of aesculin and aesculetin using only one reference compound (i. e., aesculin) was achieved by HPLC-UV at this EAW. The newly developed HPLC method revealed a good linear relationship between the two target analytes (<i>r</i>=1.0000). The limits of detection (LODs) and limits of quantification (LOQs) were 1.5 μmol/L and 3.0 μmol/L, respectively, and the average recoveries of aesculin and aesculetin were 99.0% and 97.5%. The stabilities of the sample solutions were examined, and the two analytes demonstrated good stability for 24 h. The contents of the target analytes in 10 batches of Fraxini Cortex were determined using the proposed EAW method and the classic external standard method (ESM), and comparable concentrations were obtained. The contents of aesculin and aesculetin in the 10 batches of Fra
{"title":"[Rapid determination of aesculin and aesculetin in Fraxini Cortex by high performance liquid chromatography-ultraviolet at equal absorption wavelength].","authors":"Zheng-Ming Qian, Meng-Qi Wu, Guo-Ying Tan, Li-Ling Jin, Ning Li, Ju-Ying Xie","doi":"10.3724/SP.J.1123.2023.03018","DOIUrl":"https://doi.org/10.3724/SP.J.1123.2023.03018","url":null,"abstract":"<p><p>Fraxini Cortex is a traditional Chinese herbal medicine that has been used for thousands of years to treat dampness-heat diarrhea, dysentery, red or white vaginal discharge, painful swelling or redness of the eyes, and nebula. It contains various chemical components, including coumarins, iridoids, phenolic acids, and flavonoids. Coumarins are important active ingredients in Fraxini Cortex and have antibacterial, anti-inflammatory, antioxidant, antitumor, and antiviral activities. Aesculin and aesculetin are two major coumarin components of Fraxini Cortex that are widely used in its quality evaluation. Previous HPLC methods for determination of aesculin and aesculetin present several limitations, such as long analysis times and high solvent and reference compound consumption. In this study, a rapid, eco-friendly and cost saving HPLC method for the determination of aesculin and aesculetin in Fraxini Cortex was established by using the core-shell column and equal absorption wavelength (EAW). Different factors influencing the extraction process, such as the extraction solvent, temperature, and time, were assessed to obtain the optimal extraction conditions. The results showed that Fraxini Cortex samples could be well extracted by ultrasonic extraction for 5 min with a 25% ethanol aqueous solution. A core-shell column was used, and different mobile phases and flow rates were investigated to obtain the best rapid-HPLC separation conditions. The optimized HPLC conditions were as follows: a Poroshell 120 EC-C<sub>18</sub> column (50 mm×4.6 mm, 2.7 μm), acetonitrile-0.1% formic acid aqueous solution (6∶94, v/v) as the eluent, a flow rate of 1.5 mL/min, and a column temperature of 25 ℃. The EAW of aesculin and aesculetin was a key factor in their determination using a single reference compound. EAW selection was performed in two steps. First, the UV spectra of two equimolar concentrations of the reference compounds (aesculin and aesculetin) were compared to determine the EAW of the two analytes. The EAW results were then verified by the HPLC analysis of the reference compound solutions. The final EAW of aesculin and aesculetin was 341 nm. The determination of aesculin and aesculetin using only one reference compound (i. e., aesculin) was achieved by HPLC-UV at this EAW. The newly developed HPLC method revealed a good linear relationship between the two target analytes (<i>r</i>=1.0000). The limits of detection (LODs) and limits of quantification (LOQs) were 1.5 μmol/L and 3.0 μmol/L, respectively, and the average recoveries of aesculin and aesculetin were 99.0% and 97.5%. The stabilities of the sample solutions were examined, and the two analytes demonstrated good stability for 24 h. The contents of the target analytes in 10 batches of Fraxini Cortex were determined using the proposed EAW method and the classic external standard method (ESM), and comparable concentrations were obtained. The contents of aesculin and aesculetin in the 10 batches of Fra","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"690-697"},"PeriodicalIF":0.7,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398825/pdf/cjc-41-08-690.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9958856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-01DOI: 10.3724/SP.J.1123.2022.11020
Mu Wang, Xi-Rui Zhang, Yu-Wei Dou, Hong Ye, Hai-Yang Dou
<p><p>Asymmetrical flow field-flow fractionation (AF4), a gentle tool for the separation and characterization of particles and macromolecules, has attracted increased interest in recent years owing to its broad dynamic size range and utilization of "open channel" voids in the packing or stationary phase. A steric transition phenomenon in which the sample elution mode change from the normal mode to the steric/hyperlayer mode occurs. Accurate characterization by AF4 requires the absence of steric transition, particularly when the sample has a broad size distribution, because the effect of the combination of different modes is difficult to interpret. In this study, the relative molecular mass (<i>M</i>), radius of gyration (<i>R</i><sub>g</sub>), and conformation of <i>Gastrodia elata</i> polysaccharides (GEPs) were characterized using AF4 coupled with online multi-angle light scattering (MALS) and differential refractive index (dRI) detection (AF4-MALS-dRI). Steric transition was observed during GEP separation by AF4 owing to the broad size distribution of the molecules. This phenomenon would result in the inaccurate characterization of the GEPs in terms of <i>M</i> and <i>R</i><sub>g</sub> because two GEP groups of different sizes may elute together. In this study, the effects of constant and exponentially decaying cross-flow rates, sample mass concentration, and spacer thickness on steric transition were systematically investigated. The results indicated that a high GEP mass concentration (i. e., 0.75 mg/mL) can lead to steric transition. The spacer thickness affected the resolution and retention time of the GEPs and changed the steric transition point (<i>d</i><sub>i</sub>). An exponentially decaying cross-flow rate not only adjusted the <i>d</i><sub>i</sub> of the polydisperse GEP samples but also improved the GEP resolution and shortened the analysis time. The influence of steric transition was solved under the following operating conditions: injected GEP mass concentration=0.5 mg/mL; injection volume=50 μL; spacer thickness=350 μm; detector flow rate=1.0 mL/min; and cross-flow rate exponentially decayed from 0.2 to 0.05 mL/min with a half-life of 2 min. Moreover, the influence of GEP origins and ultrasound treatment time on the <i>M</i> and <i>R</i><sub>g</sub> distributions and conformation of GEPs were investigated under the optimized operating conditions. The results showed that the <i>M</i> and <i>R</i><sub>g</sub> distributions of Yunnan and Sichuan GEPs decreased with increasing ultrasound time. When the ultrasound treatment time was 15 min, the Yunnan GEPs had a loosely hyperbranched chain conformation, whereas the Sichuan GEPs had a spherical conformation. When the ultrasound treatment time was increased to 30 or 60 min, the GEPs from both Yunnan and Sichuan had a hyperbranched chain conformation, indicating that ultrasound treatment resulted in GEP degradation. Under the same extraction conditions, GEPs from Yunnan had larger <i>M</i
{"title":"[Separation and characterization of <i>Gastrodia elata</i> polysaccharides based on asymmetrical flow field-flow fractionation: steric transition phenomenon].","authors":"Mu Wang, Xi-Rui Zhang, Yu-Wei Dou, Hong Ye, Hai-Yang Dou","doi":"10.3724/SP.J.1123.2022.11020","DOIUrl":"https://doi.org/10.3724/SP.J.1123.2022.11020","url":null,"abstract":"<p><p>Asymmetrical flow field-flow fractionation (AF4), a gentle tool for the separation and characterization of particles and macromolecules, has attracted increased interest in recent years owing to its broad dynamic size range and utilization of \"open channel\" voids in the packing or stationary phase. A steric transition phenomenon in which the sample elution mode change from the normal mode to the steric/hyperlayer mode occurs. Accurate characterization by AF4 requires the absence of steric transition, particularly when the sample has a broad size distribution, because the effect of the combination of different modes is difficult to interpret. In this study, the relative molecular mass (<i>M</i>), radius of gyration (<i>R</i><sub>g</sub>), and conformation of <i>Gastrodia elata</i> polysaccharides (GEPs) were characterized using AF4 coupled with online multi-angle light scattering (MALS) and differential refractive index (dRI) detection (AF4-MALS-dRI). Steric transition was observed during GEP separation by AF4 owing to the broad size distribution of the molecules. This phenomenon would result in the inaccurate characterization of the GEPs in terms of <i>M</i> and <i>R</i><sub>g</sub> because two GEP groups of different sizes may elute together. In this study, the effects of constant and exponentially decaying cross-flow rates, sample mass concentration, and spacer thickness on steric transition were systematically investigated. The results indicated that a high GEP mass concentration (i. e., 0.75 mg/mL) can lead to steric transition. The spacer thickness affected the resolution and retention time of the GEPs and changed the steric transition point (<i>d</i><sub>i</sub>). An exponentially decaying cross-flow rate not only adjusted the <i>d</i><sub>i</sub> of the polydisperse GEP samples but also improved the GEP resolution and shortened the analysis time. The influence of steric transition was solved under the following operating conditions: injected GEP mass concentration=0.5 mg/mL; injection volume=50 μL; spacer thickness=350 μm; detector flow rate=1.0 mL/min; and cross-flow rate exponentially decayed from 0.2 to 0.05 mL/min with a half-life of 2 min. Moreover, the influence of GEP origins and ultrasound treatment time on the <i>M</i> and <i>R</i><sub>g</sub> distributions and conformation of GEPs were investigated under the optimized operating conditions. The results showed that the <i>M</i> and <i>R</i><sub>g</sub> distributions of Yunnan and Sichuan GEPs decreased with increasing ultrasound time. When the ultrasound treatment time was 15 min, the Yunnan GEPs had a loosely hyperbranched chain conformation, whereas the Sichuan GEPs had a spherical conformation. When the ultrasound treatment time was increased to 30 or 60 min, the GEPs from both Yunnan and Sichuan had a hyperbranched chain conformation, indicating that ultrasound treatment resulted in GEP degradation. Under the same extraction conditions, GEPs from Yunnan had larger <i>M</i","PeriodicalId":9864,"journal":{"name":"色谱","volume":"41 8","pages":"714-721"},"PeriodicalIF":0.7,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398820/pdf/cjc-41-08-714.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10330714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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