Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.013
Kohei Kawabata, Takato Uchikata, Keiko Matsumoto, H. Nishi
A photodiode array detector (PDA) is frequently utilized as a detector in high-performance liquid chromatography (HPLC) system for a detection of various compounds. A PDA emits a light of a wide range wavelength including ultraviolet light (UV) which has a possibility to induce photodegradation of analyzed compounds. If so, target compounds might be degraded when analyzed in this HPLC system. Therefore, photoprotection during HPLC analysis is required for the accurate analysis. In this study, the protective effect of a UV cut-off filter, which can cut off UV especially at shorter wavelength (< 240 nm), on the quantitativity of a photodegradable compound L -ascorbic acid (AA) was examined. A UV cut-off filter prevents AA from photodegradation, followed by the improvement of several parameters of a calibration curve. Furthermore, this protective potency was significant in the case that photodegradability of AA was enhanced with the conditions such as a small injection volume and a low flow rate. This study strongly suggests that the UV cut-off filter is a useful equipment when analyzing photodegradable compounds.
{"title":"UV Cut-Off Filter of a Photodiode Array Detector Improves the Quantitativity of L-Ascorbic Acid Through Its Photoprotection","authors":"Kohei Kawabata, Takato Uchikata, Keiko Matsumoto, H. Nishi","doi":"10.15583/jpchrom.2020.013","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.013","url":null,"abstract":"A photodiode array detector (PDA) is frequently utilized as a detector in high-performance liquid chromatography (HPLC) system for a detection of various compounds. A PDA emits a light of a wide range wavelength including ultraviolet light (UV) which has a possibility to induce photodegradation of analyzed compounds. If so, target compounds might be degraded when analyzed in this HPLC system. Therefore, photoprotection during HPLC analysis is required for the accurate analysis. In this study, the protective effect of a UV cut-off filter, which can cut off UV especially at shorter wavelength (< 240 nm), on the quantitativity of a photodegradable compound L -ascorbic acid (AA) was examined. A UV cut-off filter prevents AA from photodegradation, followed by the improvement of several parameters of a calibration curve. Furthermore, this protective potency was significant in the case that photodegradability of AA was enhanced with the conditions such as a small injection volume and a low flow rate. This study strongly suggests that the UV cut-off filter is a useful equipment when analyzing photodegradable compounds.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42030928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.014
K. Todoroki, Tatsuki Nakano, H. Hayashi, H. Mizuno, J. Min, T. Toyo’oka
This report presents two fluorescence labeling methods for therapeutic monoclonal antibody, bevacizumab, to increase its detection sensitivity for fluorescence detection. One method is high-temperature reversed-phase LC (HT-RPLC) following post-column fluorogenic derivatization using o -phthalaldehyde with thiol. Another method is pre-column derivatization using Zenon Alexa Fluor 488 protein-tag following size-exclusion chromatography (SEC). The calibration curves of bevacizumab were 1–50 μg/mL (post-column method) and 0.1–10 μg/mL (pre-column method). Both methods showed good correlation coefficients (r 2 > 0.991). The LOD and the LOQ of bevacizumab were, respectively, 0.13 and 0.43 μg/mL (post-column method) and 0.03 and 0.1 μg/mL (pre-column method). The sensitivities were about 2 and 10 times higher than that of native fluorescence detection. The proposed methods were applied to bevacizumab spiked human plasma samples. The bevacizumab in plasma samples was purified selectively with immunoaffinity beads and detected as a single peak using HT-RPLC or SEC with fluorescence detection.
{"title":"Fluorescence Bioanalysis of Bevacizumab Using Pre-Column and Post-Column Derivatization – Liquid Chromatography After Immunoaffinity Magnetic Purification","authors":"K. Todoroki, Tatsuki Nakano, H. Hayashi, H. Mizuno, J. Min, T. Toyo’oka","doi":"10.15583/jpchrom.2020.014","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.014","url":null,"abstract":"This report presents two fluorescence labeling methods for therapeutic monoclonal antibody, bevacizumab, to increase its detection sensitivity for fluorescence detection. One method is high-temperature reversed-phase LC (HT-RPLC) following post-column fluorogenic derivatization using o -phthalaldehyde with thiol. Another method is pre-column derivatization using Zenon Alexa Fluor 488 protein-tag following size-exclusion chromatography (SEC). The calibration curves of bevacizumab were 1–50 μg/mL (post-column method) and 0.1–10 μg/mL (pre-column method). Both methods showed good correlation coefficients (r 2 > 0.991). The LOD and the LOQ of bevacizumab were, respectively, 0.13 and 0.43 μg/mL (post-column method) and 0.03 and 0.1 μg/mL (pre-column method). The sensitivities were about 2 and 10 times higher than that of native fluorescence detection. The proposed methods were applied to bevacizumab spiked human plasma samples. The bevacizumab in plasma samples was purified selectively with immunoaffinity beads and detected as a single peak using HT-RPLC or SEC with fluorescence detection.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42272181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.012
Takuya Fujiwara, T. Funatsu, M. Tsunoda
We have previously reported analytical methods for the quantification of catecholamines (norepinephrine, epinephrine, and dopamine) via simple pretreatment using a monolithic silica disk-packed spin column with an attached phenylboronate moiety. However, under certain conditions, splitting in the dopamine peak was observed. In this study, we investigated the reason for this peak splitting and found that anions in the basic buffer solution used in the extraction influenced the peak shape. The extraction could be improved via additionally washing the column with a low-concentration buffer. The extraction recoveries of the catecholamines via the improved method were in the range of 95.9–100.8%. Thus, the improved method is expected to be more reliable for the quantification of catecholamines in biological samples.
{"title":"Improved Extraction Method for Catecholamines Using Monolithic Silica Disk-Packed Spin Column","authors":"Takuya Fujiwara, T. Funatsu, M. Tsunoda","doi":"10.15583/jpchrom.2020.012","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.012","url":null,"abstract":"We have previously reported analytical methods for the quantification of catecholamines (norepinephrine, epinephrine, and dopamine) via simple pretreatment using a monolithic silica disk-packed spin column with an attached phenylboronate moiety. However, under certain conditions, splitting in the dopamine peak was observed. In this study, we investigated the reason for this peak splitting and found that anions in the basic buffer solution used in the extraction influenced the peak shape. The extraction could be improved via additionally washing the column with a low-concentration buffer. The extraction recoveries of the catecholamines via the improved method were in the range of 95.9–100.8%. Thus, the improved method is expected to be more reliable for the quantification of catecholamines in biological samples.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41341713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.016
Y. Shibata, Tomohiro Yamada, Eiji Sugiyama, H. Mizuno, K. Todoroki
Herein, we report an intact LC–native fluorescence analysis method for therapeutic monoclonal antibodies (mAbs) based on a centrifugal filtration device with adsorption suppression treatment. Coating the centrifugal filtration device with MPC monomer suppressed the non-specific adsorption of mAbs, especially in the low concentration range; trastuzumab could be quantitatively and sensitively analyzed in the 0.2–10 μg/mL range. In this analysis, the average concentration factor over the entire concentration range was approximately 25 times. The other mAbs (bevacizumab, rituximab, nivolumab) also showed good linearity with R 2 ≥ 0.996, and the average concentration factors were similar to that obtained for trastuzumab. This method can potentially be used in combination with affinity purification for simple and sensitive bioanalysis.
{"title":"Sensitive Method for LC Analysis of Therapeutic Monoclonal Antibodies Using a Centrifugal Filtration Device with Adsorption Suppression Treatment","authors":"Y. Shibata, Tomohiro Yamada, Eiji Sugiyama, H. Mizuno, K. Todoroki","doi":"10.15583/jpchrom.2020.016","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.016","url":null,"abstract":"Herein, we report an intact LC–native fluorescence analysis method for therapeutic monoclonal antibodies (mAbs) based on a centrifugal filtration device with adsorption suppression treatment. Coating the centrifugal filtration device with MPC monomer suppressed the non-specific adsorption of mAbs, especially in the low concentration range; trastuzumab could be quantitatively and sensitively analyzed in the 0.2–10 μg/mL range. In this analysis, the average concentration factor over the entire concentration range was approximately 25 times. The other mAbs (bevacizumab, rituximab, nivolumab) also showed good linearity with R 2 ≥ 0.996, and the average concentration factors were similar to that obtained for trastuzumab. This method can potentially be used in combination with affinity purification for simple and sensitive bioanalysis.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41355766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.011
Tomohiro Motono, Takayuki Kanayama, S. Kitagawa, Yoshinori Iiguni, H. Ohtani
In ultralow-temperature HPLC, analyte retention is often enhanced, inhibiting elution. To solve this problem, we have investigated the use of low-molecular-weight hydrocarbons, methane and ethane, as the mobile phase in a monolithic ODS column. Analyte retention was successfully reduced by the use of these mobile phases, and elution of mono- and di-chloromethane and n -octane, which were not eluted in our previous work using a liquid nitrogen based mobile phase, was achieved. The analysis of octane structural isomers revealed that, in cryogenic HPLC, the retention of branched octanes was significantly reduced compared to the retention of n -octane, i . e ., the retention factor of iso -octane (2,2,4-trimethylpentane) was almost negligible. The retention factors of branched octanes were distributed between those of n -pentane and n -heptane in HPLC at -176°C, whereas, in gas chromatography at 50°C, these values were between those of n -heptane and n -octane.
{"title":"Ultralow-Temperature HPLC Using Low-Molecular-Weight Hydrocarbons as Mobile Phases","authors":"Tomohiro Motono, Takayuki Kanayama, S. Kitagawa, Yoshinori Iiguni, H. Ohtani","doi":"10.15583/jpchrom.2020.011","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.011","url":null,"abstract":"In ultralow-temperature HPLC, analyte retention is often enhanced, inhibiting elution. To solve this problem, we have investigated the use of low-molecular-weight hydrocarbons, methane and ethane, as the mobile phase in a monolithic ODS column. Analyte retention was successfully reduced by the use of these mobile phases, and elution of mono- and di-chloromethane and n -octane, which were not eluted in our previous work using a liquid nitrogen based mobile phase, was achieved. The analysis of octane structural isomers revealed that, in cryogenic HPLC, the retention of branched octanes was significantly reduced compared to the retention of n -octane, i . e ., the retention factor of iso -octane (2,2,4-trimethylpentane) was almost negligible. The retention factors of branched octanes were distributed between those of n -pentane and n -heptane in HPLC at -176°C, whereas, in gas chromatography at 50°C, these values were between those of n -heptane and n -octane.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44046995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.017
Koki Nakagami, Misato Amiya, K. Shimizu, Ohjiro Sumiya, Ryota Koike, I. Ueta, Yoshihiro Saito
Poly(butylene terephthalate)-coated silica (PBT) have been introduced as a stationary phase in liquid chromatography (LC) and the retention behavior of polycyclic aromatic compounds (PACs) was evaluated in reversed-phase LC. The trend for the retention was compared with that obtained on two types of commercially-available octadecylsilica (ODS) phases and phenylbutylsilica (PBS) phase. A good liner relationship between molecular size of planar PACs and the corresponding logarithmic retention factor was confirmed on the PBT stationary phase, and the trend is quite similar to that obtained on a conventional polymeric ODS stationary phase. In addition, a good molecular shape recognition capability of the PBT stationary phase was confirmed for several solute pairs consisted of planar and non-planar PACs with a similar two-dimensional molecular size. The selectivities to some planar/non-planar solute pairs on the PBT stationary phase were significantly better than conventional ODS phases, even when compared with that of typical polymeric ODS stationary phases operated in a similar experimental condition. In the case of structural isomers of dichlorobenzene and dibromobenzene, the elution order on the PBT stationary phase was o-, mand p-, however the corresponding elution order in typical ODS phases, and PBS phase was different, o-, pand m-. The results can be explained on the basis of the molecular-molecular interaction between the stationary phase ligand and the analyte molecule, because the PBT stationary phase has a similar partial chemical structure to these p-isomers on the silica support.
{"title":"Retention Behavior of Various Aromatic Compounds on Poly(butylene terephthalate) Stationary Phase in Liquid Chromatography","authors":"Koki Nakagami, Misato Amiya, K. Shimizu, Ohjiro Sumiya, Ryota Koike, I. Ueta, Yoshihiro Saito","doi":"10.15583/jpchrom.2020.017","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.017","url":null,"abstract":"Poly(butylene terephthalate)-coated silica (PBT) have been introduced as a stationary phase in liquid chromatography (LC) and the retention behavior of polycyclic aromatic compounds (PACs) was evaluated in reversed-phase LC. The trend for the retention was compared with that obtained on two types of commercially-available octadecylsilica (ODS) phases and phenylbutylsilica (PBS) phase. A good liner relationship between molecular size of planar PACs and the corresponding logarithmic retention factor was confirmed on the PBT stationary phase, and the trend is quite similar to that obtained on a conventional polymeric ODS stationary phase. In addition, a good molecular shape recognition capability of the PBT stationary phase was confirmed for several solute pairs consisted of planar and non-planar PACs with a similar two-dimensional molecular size. The selectivities to some planar/non-planar solute pairs on the PBT stationary phase were significantly better than conventional ODS phases, even when compared with that of typical polymeric ODS stationary phases operated in a similar experimental condition. In the case of structural isomers of dichlorobenzene and dibromobenzene, the elution order on the PBT stationary phase was o-, mand p-, however the corresponding elution order in typical ODS phases, and PBS phase was different, o-, pand m-. The results can be explained on the basis of the molecular-molecular interaction between the stationary phase ligand and the analyte molecule, because the PBT stationary phase has a similar partial chemical structure to these p-isomers on the silica support.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67104157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.15583/jpchrom.2020.015
Aogu Furusho, Mintranee Obromsuk, T. Akita, M. Mita, M. Nagano, P. Rojsitthisak, K. Hamase
A reversed-phase high-performance liquid chromatographic (HPLC) method using pre-column derivatization with o -phthalaldehyde (OPA) plus N - tert -butyloxycarbonyl- D -cysteine (Boc- D -Cys) has been developed for the determination of aspartic acid (Asp), serine (Ser) and alanine (Ala) enantiomers. D -Amino acids in the real world samples are trace in most cases, and their small peaks should be eluted faster than the huge peaks of the L -forms in order to avoid overlapping. Amino acids were rapidly derivatized at room temperature with OPA plus Boc- D -Cys under simple conditions and were detected by their fluorescence. The target amino acid enantiomers were separated within 60 min on a reversed-phase column, CAPCELL PAK C18 MG II (4.6 x 200 mm), and their resolution values were higher than 2.14. The developed system was successfully validated using standard amino acids, and sufficient calibration lines ( r 2 > 0.9983) and precision (RSD < 5.29%) results were obtained. In a Japanese traditionally fermented amber rice vinegar, all of the target D -amino acids were observed, and their % D values were 21.5 for Asp, 6.8 for Ser and 22.9 for Ala.
建立了邻苯二甲醛（OPA）加N-叔丁氧基羰基-D-半胱氨酸（Boc-D-Cys）柱前衍生化反相高效液相色谱法测定天冬氨酸（Asp）、丝氨酸（Ser）和丙氨酸（Ala）对映体。在大多数情况下，真实世界样品中的D-氨基酸是微量的，它们的小峰应该比L-形式的大峰洗脱得更快，以避免重叠。在简单的条件下，用OPA加Boc-D-Cys在室温下快速衍生氨基酸，并用它们的荧光进行检测。目标氨基酸对映体在反相柱CAPCELL PAK C18 MG II（4.6 x 200mm）上在60分钟内分离，其分辨率值高于2.14。用标准氨基酸对所开发的系统进行了验证，获得了足够的校准线（r2＞0.9983）和精密度（RSD<5.29%）结果。在日本传统发酵的琥珀米醋中，观察到所有的目标D-氨基酸，Asp的%D值为21.5，Ser为6.8，Ala为22.9。
{"title":"High-Performance Liquid Chromatographic Determination of Chiral Amino Acids Using Pre-Column Derivatization with o-Phthalaldehyde and N-tert-Butyloxycarbonyl-D-cysteine and Application to Vinegar Samples","authors":"Aogu Furusho, Mintranee Obromsuk, T. Akita, M. Mita, M. Nagano, P. Rojsitthisak, K. Hamase","doi":"10.15583/jpchrom.2020.015","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.015","url":null,"abstract":"A reversed-phase high-performance liquid chromatographic (HPLC) method using pre-column derivatization with o -phthalaldehyde (OPA) plus N - tert -butyloxycarbonyl- D -cysteine (Boc- D -Cys) has been developed for the determination of aspartic acid (Asp), serine (Ser) and alanine (Ala) enantiomers. D -Amino acids in the real world samples are trace in most cases, and their small peaks should be eluted faster than the huge peaks of the L -forms in order to avoid overlapping. Amino acids were rapidly derivatized at room temperature with OPA plus Boc- D -Cys under simple conditions and were detected by their fluorescence. The target amino acid enantiomers were separated within 60 min on a reversed-phase column, CAPCELL PAK C18 MG II (4.6 x 200 mm), and their resolution values were higher than 2.14. The developed system was successfully validated using standard amino acids, and sufficient calibration lines ( r 2 > 0.9983) and precision (RSD < 5.29%) results were obtained. In a Japanese traditionally fermented amber rice vinegar, all of the target D -amino acids were observed, and their % D values were 21.5 for Asp, 6.8 for Ser and 22.9 for Ala.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" 46","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41254177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-20DOI: 10.15583/jpchrom.2019.025
Takahiro Kawase, K. Hatanaka, M. Kono, Y. Shirahase, K. Ochiai, S. Takashiba, T. Tsukahara
Upon absorption in the intestine of the host animal, the main function of short-chain fatty acids (SCFAs), mainly acetate, propionate and n-butyrate, is as metabolic energy. SCFAs, n-butyrate in particular, can also be found in the mouth. An excess of oral SCFAs may cause not only periodontal diseases but also systemic abnormalities in humans. Previously, we reported a method for simultaneous detection by gas chromatography-mass spectrometry (GC-MS) of acetate, propionate and n-butyrate in serum, urine and saliva. In the present study we used a modified version of this method to detect not only acetate, propionate and n-butyrate, but also iso-butyrate, n-valerate, iso-valerate and caproate, because the latter are suggested to be associated with periodontal diseases. Detection ranges of SCFAs were as follows; 6.25-400 µmol/L (acetate), 0.781-100 µmol/L (propionate and n-butyrate), 0.391-50 µmol/L (iso-butyrate), 0.781-50 µmol/L (n-valerate and iso-valerate) and 1.56-50 µmol/L (caproate). Furthermore, we validated the modified detection method with triple freeze-thaw-cycle recovery tests and intra- and inter-day repeatability. Freezing and thawing did not influence the concentrations of SCFAs in saliva. Upon analysis of five clinical saliva samples, it was observed that, except for n-valerate, which was detected only in two samples, all SCFAs were detected in saliva samples. To conclude, we were able to use a modified method to analyze successfully by GC-MS the salivary concentrations of SCFAs. In addition, we simultaneously detected the salivary concentrations of iso-butyrate, iso-valerate, n-valerate and caproate. This improved method was proved to be reliable to measure the concentrations of SCFAs in saliva.
{"title":"Simultaneous Determination of 7 Short-Chain Fatty Acids in Human Saliva by High-Sensitivity Gas Chromatography-Mass Spectrometry","authors":"Takahiro Kawase, K. Hatanaka, M. Kono, Y. Shirahase, K. Ochiai, S. Takashiba, T. Tsukahara","doi":"10.15583/jpchrom.2019.025","DOIUrl":"https://doi.org/10.15583/jpchrom.2019.025","url":null,"abstract":"Upon absorption in the intestine of the host animal, the main function of short-chain fatty acids (SCFAs), mainly acetate, propionate and n-butyrate, is as metabolic energy. SCFAs, n-butyrate in particular, can also be found in the mouth. An excess of oral SCFAs may cause not only periodontal diseases but also systemic abnormalities in humans. Previously, we reported a method for simultaneous detection by gas chromatography-mass spectrometry (GC-MS) of acetate, propionate and n-butyrate in serum, urine and saliva. In the present study we used a modified version of this method to detect not only acetate, propionate and n-butyrate, but also iso-butyrate, n-valerate, iso-valerate and caproate, because the latter are suggested to be associated with periodontal diseases. Detection ranges of SCFAs were as follows; 6.25-400 µmol/L (acetate), 0.781-100 µmol/L (propionate and n-butyrate), 0.391-50 µmol/L (iso-butyrate), 0.781-50 µmol/L (n-valerate and iso-valerate) and 1.56-50 µmol/L (caproate). Furthermore, we validated the modified detection method with triple freeze-thaw-cycle recovery tests and intra- and inter-day repeatability. Freezing and thawing did not influence the concentrations of SCFAs in saliva. Upon analysis of five clinical saliva samples, it was observed that, except for n-valerate, which was detected only in two samples, all SCFAs were detected in saliva samples. To conclude, we were able to use a modified method to analyze successfully by GC-MS the salivary concentrations of SCFAs. In addition, we simultaneously detected the salivary concentrations of iso-butyrate, iso-valerate, n-valerate and caproate. This improved method was proved to be reliable to measure the concentrations of SCFAs in saliva.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.15583/jpchrom.2019.025","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47921694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-20DOI: 10.15583/jpchrom.2020.009
Makoto Takada, Y. Ohba, T. Kabashima, K. Nakashima, M. Wada
The combination of methotrexate (MTX) and non-steroidal anti-inflammatory drugs (NSAIDs), which is frequently used for rheumatoid arthritis (RA) treatment, courses of adverse events. To prevent these, simultaneous monitoring of these compounds is available. Therefore, we developed a new method for MTX and NSAIDs such as loxoprofen (LP), meloxicam (MX), lornoxicam (LX), diclofenac (DF) and celecoxib (CX) determination using HPLC with simple pretreatment of human serum sample. The separation of MTX and 5 NSAIDs was performed on C6-Phenyl column with gradient elution using 10 mmol/L ammonium acetate aqueous solution and methanol, and achieved within 25 min of analytical runtime. Calibration curves using standards showed good linearity ( r 2 >0.9998) in the range of 0.02-500 pmol/10 μL injection for MTX, 10-500 pmol for LP, 0.2-500 pmol for MX and DF, 0.05-500 pmol for LX and 2-500 pmol for CX. The detection limits of the proposed method were at least less than 96.0 fmol, and repeatability was less than 4.62 RSD%. In addition, acceptable precision of less than 10.19 RSD% and recovery of more than 54.4% of the method were obtained because the peaks of MTX and NSAIDs could be well-separated from those of interferings in serum. the method be useful to avoid occurring adverse events, and confirm the curative effect of MTX and NSAIDs.
{"title":"Simple Simultaneous Assay of Methotrexate and Non-Steroidal Anti-Inflammatory Drugs by HPLC","authors":"Makoto Takada, Y. Ohba, T. Kabashima, K. Nakashima, M. Wada","doi":"10.15583/jpchrom.2020.009","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.009","url":null,"abstract":"The combination of methotrexate (MTX) and non-steroidal anti-inflammatory drugs (NSAIDs), which is frequently used for rheumatoid arthritis (RA) treatment, courses of adverse events. To prevent these, simultaneous monitoring of these compounds is available. Therefore, we developed a new method for MTX and NSAIDs such as loxoprofen (LP), meloxicam (MX), lornoxicam (LX), diclofenac (DF) and celecoxib (CX) determination using HPLC with simple pretreatment of human serum sample. The separation of MTX and 5 NSAIDs was performed on C6-Phenyl column with gradient elution using 10 mmol/L ammonium acetate aqueous solution and methanol, and achieved within 25 min of analytical runtime. Calibration curves using standards showed good linearity ( r 2 >0.9998) in the range of 0.02-500 pmol/10 μL injection for MTX, 10-500 pmol for LP, 0.2-500 pmol for MX and DF, 0.05-500 pmol for LX and 2-500 pmol for CX. The detection limits of the proposed method were at least less than 96.0 fmol, and repeatability was less than 4.62 RSD%. In addition, acceptable precision of less than 10.19 RSD% and recovery of more than 54.4% of the method were obtained because the peaks of MTX and NSAIDs could be well-separated from those of interferings in serum. the method be useful to avoid occurring adverse events, and confirm the curative effect of MTX and NSAIDs.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45212864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-20DOI: 10.15583/jpchrom.2020.010
T. Takayanagi, S. Iwasaki, Kotaro Morita, N. Hirayama, H. Mizuguchi
Carbon nanodots (CNDs) prepared from glutamic acid or glutathione in an electric furnace were characterized by capillary electrophoresis. Two major peaks were detected in the electropherograms by capillary zone electrophoresis, corresponding to anionic and less-charged CNDs. The effective electrophoretic mobility of the anionic CND formed from glutamic acid was almost identical over neutral to weakly alkaline pH range, and the CND would not contain significant amount of amino group. On the other hand, the effective electrophoretic mobility tended to decrease with decreasing pH at weakly acidic pH conditions, suggesting the functional groups of carboxylate moiety on the anionic CNDs. Dodecyl sulfate ion was added in the separation buffer to give anionic charge to the less-charged CND by adsorption. However, the anionic charge induced was little, and the dodecyl sulfate ion was not likely adsorbed on the less-charged CND and the CND would be hydrophilic.
{"title":"Capillary Electrophoretic Characterization of Carbon Nanodots Prepared from Glutamic Acid in an Electric Furnace","authors":"T. Takayanagi, S. Iwasaki, Kotaro Morita, N. Hirayama, H. Mizuguchi","doi":"10.15583/jpchrom.2020.010","DOIUrl":"https://doi.org/10.15583/jpchrom.2020.010","url":null,"abstract":"Carbon nanodots (CNDs) prepared from glutamic acid or glutathione in an electric furnace were characterized by capillary electrophoresis. Two major peaks were detected in the electropherograms by capillary zone electrophoresis, corresponding to anionic and less-charged CNDs. The effective electrophoretic mobility of the anionic CND formed from glutamic acid was almost identical over neutral to weakly alkaline pH range, and the CND would not contain significant amount of amino group. On the other hand, the effective electrophoretic mobility tended to decrease with decreasing pH at weakly acidic pH conditions, suggesting the functional groups of carboxylate moiety on the anionic CNDs. Dodecyl sulfate ion was added in the separation buffer to give anionic charge to the less-charged CND by adsorption. However, the anionic charge induced was little, and the dodecyl sulfate ion was not likely adsorbed on the less-charged CND and the CND would be hydrophilic.","PeriodicalId":91226,"journal":{"name":"Chromatography (Basel)","volume":"41 1","pages":"103-107"},"PeriodicalIF":0.0,"publicationDate":"2020-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48661743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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