A bimetallic cuprous complex was accidentally reported, during synthesis of a dinucleating spacer incorporating two 2-chloropyridine units through Sandmayer reaction. The product was characterized by elemental analysis, FAB-Mass, FT-IR, UV, magnetic susceptibility and 1H-NMR spectroscopic method. A possible mechanism is also proposed.
{"title":"Experiences during Synthesis of a Dinucleating Spacer Incorporating 2-Chloropyridine Units Through Sandmayer Reaction","authors":"S. Shukla, P. Gaur, R. Mehrotra, R. Srivastava","doi":"10.1155/2012/646397","DOIUrl":"https://doi.org/10.1155/2012/646397","url":null,"abstract":"A bimetallic cuprous complex was accidentally reported, during synthesis of a dinucleating spacer incorporating two 2-chloropyridine units through Sandmayer reaction. The product was characterized by elemental analysis, FAB-Mass, FT-IR, UV, magnetic susceptibility and 1H-NMR spectroscopic method. A possible mechanism is also proposed.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/646397","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64340694","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}
In this paper, efficiency of nano-ZnO particles on catalytic ozonation of 4-nitrochlorobenzene (4NCB) using semi-batch reactor has been studied at various pHs. During the catalytic ozonation, TOC and concentration of nitrate ions was monitored. Results indicate that degradation of 4NCB was improved by combination of nano-ZnO with ozone. The effect of ZnO particle size and pH are also examined. According to the results, concentration of 4NCB decreased with increasing of particle size from nanosized to microsized and pH from 3.0 to 9.0. Based on the results, it suggests radical hydroxyl does not affect on the degradation of 4NCB in catalytic ozonation, but the surface of catalyst plays main role. Kinetic studies showed degradation of 4NCB followed pseudo-first-order kinetic and maximum degradation rate was observed at pH=3.
{"title":"Nano-Catalytic Ozonation of 4-Nitrochlorobenzene in Aqueous Solutions","authors":"S. Tabatabaei, A. Mehrizad, P. Gharbani","doi":"10.1155/2012/696418","DOIUrl":"https://doi.org/10.1155/2012/696418","url":null,"abstract":"In this paper, efficiency of nano-ZnO particles on catalytic ozonation of 4-nitrochlorobenzene (4NCB) using semi-batch reactor has been studied at various pHs. During the catalytic ozonation, TOC and concentration of nitrate ions was monitored. Results indicate that degradation of 4NCB was improved by combination of nano-ZnO with ozone. The effect of ZnO particle size and pH are also examined. According to the results, concentration of 4NCB decreased with increasing of particle size from nanosized to microsized and pH from 3.0 to 9.0. Based on the results, it suggests radical hydroxyl does not affect on the degradation of 4NCB in catalytic ozonation, but the surface of catalyst plays main role. Kinetic studies showed degradation of 4NCB followed pseudo-first-order kinetic and maximum degradation rate was observed at pH=3.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/696418","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64344554","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}
The interactions between epirubicin (EPR) and double stranded DNA (ds-DNA) have been studied by UV-Vis spectrophotometry, cyclic voltammetry, fluorescence spectroscopy and viscometery. The apparent binding constant of epirubicin with DNA was found to be 3.8 × 105 mol-1 L and was studied at different temperatures. It indicated that the former method could be successfully applied to the determination of epirubicin. Also, the voltammetric behavior of EPR was investigated at glassy carbon electrode using cyclic voltammetry. Thermodynamic parameters including ∆H0, ∆G0 and ∆S0 were determined as -5.7×104, -3.13×104 J mol-1 and -87.96 J mol-1 K-1 respectively. One indication of the strong interaction between DNA and EP was increasing of viscosity. The diffusion coefficients of EP in the absence (D0)f and presence of ds-DNA (D0)b was calculated as 5.04×10-6 and 1.13×10-6 Cm2 s-1 respectively. According to the thermodynamic parameters, the main binding force could be judged. The experimental results revealed that EPR and ds-DNA had strong interactions. The mechanism of quenching belonged to static quenching and the main sort of binding force was intercalation.
{"title":"Spectroscopic and Electrochemical Studies on the Interaction of Epirubicin with Fish Sperm DNA","authors":"R. Hajian, E. Ekhlasi, R. Daneshvar","doi":"10.1155/2012/738678","DOIUrl":"https://doi.org/10.1155/2012/738678","url":null,"abstract":"The interactions between epirubicin (EPR) and double stranded DNA (ds-DNA) have been studied by UV-Vis spectrophotometry, cyclic voltammetry, fluorescence spectroscopy and viscometery. The apparent binding constant of epirubicin with DNA was found to be 3.8 × 105 mol-1 L and was studied at different temperatures. It indicated that the former method could be successfully applied to the determination of epirubicin. Also, the voltammetric behavior of EPR was investigated at glassy carbon electrode using cyclic voltammetry. Thermodynamic parameters including ∆H0, ∆G0 and ∆S0 were determined as -5.7×104, -3.13×104 J mol-1 and -87.96 J mol-1 K-1 respectively. One indication of the strong interaction between DNA and EP was increasing of viscosity. The diffusion coefficients of EP in the absence (D0)f and presence of ds-DNA (D0)b was calculated as 5.04×10-6 and 1.13×10-6 Cm2 s-1 respectively. According to the thermodynamic parameters, the main binding force could be judged. The experimental results revealed that EPR and ds-DNA had strong interactions. The mechanism of quenching belonged to static quenching and the main sort of binding force was intercalation.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/738678","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64348570","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}
The powder of mosambi fruit peelings (PMFP) was used as an adsorbent for the removal of heavy metal like Cr (VI) from aqueous solutions was studied using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, adsorbent dosage, and the particle size of adsorbent has been considered in batch tests. Sorbent ability to adsorb Cr (VI) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration was 10 mg/lit, pH=2, agitation time – 60 min, an adsorbent dose (150 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=7.51(mg/g) and b=1.69(mg/lit)] Freundlich constant(Kf=2.94), Lagergren rate constants (Kad (min-1)=5.75 x 10-2) for [Cr(VI)] 10 mg/lit were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model.
{"title":"Studies on Removal of Cr (VI) from Aqueous Solutions Using Powder of Mosambi Fruit Peelings (PMFP) As a Low Cost Sorbent","authors":"R. H. Krishna, A. Swamy","doi":"10.1155/2012/769674","DOIUrl":"https://doi.org/10.1155/2012/769674","url":null,"abstract":"The powder of mosambi fruit peelings (PMFP) was used as an adsorbent for the removal of heavy metal like Cr (VI) from aqueous solutions was studied using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, adsorbent dosage, and the particle size of adsorbent has been considered in batch tests. Sorbent ability to adsorb Cr (VI) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration was 10 mg/lit, pH=2, agitation time – 60 min, an adsorbent dose (150 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=7.51(mg/g) and b=1.69(mg/lit)] Freundlich constant(Kf=2.94), Lagergren rate constants (Kad (min-1)=5.75 x 10-2) for [Cr(VI)] 10 mg/lit were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/769674","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64352329","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}
The synthesis of series of 3,4-dialkyl-2,6-diaryl-piperidin-4-ol derivatives (7-12) by reduction of cis-3-alkyl-2,6-diarylpiperidin-4-one (1-6) using Grignard reagent has been reported. The synthesized heterocycles have been characterized on basis of spectroscopic data and their conformation has also been discussed.
{"title":"Synthesis of Substituted 3,4-Dialkyl-2,6-Diaryl- Piperidin-4-ol Derivatives and Their Conformational Study","authors":"T. Maruthavanan, P. Venkatesan","doi":"10.1155/2012/783605","DOIUrl":"https://doi.org/10.1155/2012/783605","url":null,"abstract":"The synthesis of series of 3,4-dialkyl-2,6-diaryl-piperidin-4-ol derivatives (7-12) by reduction of cis-3-alkyl-2,6-diarylpiperidin-4-one (1-6) using Grignard reagent has been reported. The synthesized heterocycles have been characterized on basis of spectroscopic data and their conformation has also been discussed.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/783605","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64352417","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}
Geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance of 2-amino-3-nitropyridine (ANP) were investigated by utilizing ab-initio (MP2) and DFT(B3LYP) using 6- 311++G(d,p) basis set. Geometrical parameters (bond lengths, bond angles and torsion angles) were computed and compared with the experimental values obtained using X-ray single crystal measurements of the title compound. IR spectra were obtained and assigned by vibrational analysis. Comparing the theoretically calculated values (bond lengths, bond and dihedral angles) using both B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) methods of calculations with the experimentally determined data by X-ray single crystal measurements, all the data obtained in this investigation were considered to be reliable. The theoretical infrared spectra have been successfully simulated by means of DFT and MP2 levels of calculations. The 1 H and 13 C nuclear magnetic resonance (NMR) chemical shifts of 2-amino-3-nitropyridine were calculated using the GIAO method in DMSO solution using IEF-PCM model and compared with the experimental data. Intramolecular hydrogen bonding interaction in this compound was investigated by means of the NBO analysis. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule.
{"title":"Structural and Theoretical Studies of 2-amino-3-nitropyridine","authors":"A. Dahy, I. Kh, N. M. El-Salam, S. Arabia","doi":"10.1155/2012/895240","DOIUrl":"https://doi.org/10.1155/2012/895240","url":null,"abstract":"Geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance of 2-amino-3-nitropyridine (ANP) were investigated by utilizing ab-initio (MP2) and DFT(B3LYP) using 6- 311++G(d,p) basis set. Geometrical parameters (bond lengths, bond angles and torsion angles) were computed and compared with the experimental values obtained using X-ray single crystal measurements of the title compound. IR spectra were obtained and assigned by vibrational analysis. Comparing the theoretically calculated values (bond lengths, bond and dihedral angles) using both B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) methods of calculations with the experimentally determined data by X-ray single crystal measurements, all the data obtained in this investigation were considered to be reliable. The theoretical infrared spectra have been successfully simulated by means of DFT and MP2 levels of calculations. The 1 H and 13 C nuclear magnetic resonance (NMR) chemical shifts of 2-amino-3-nitropyridine were calculated using the GIAO method in DMSO solution using IEF-PCM model and compared with the experimental data. Intramolecular hydrogen bonding interaction in this compound was investigated by means of the NBO analysis. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/895240","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64365246","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}
The novel 2-[(E)-2-aryl-1-ethenyl]-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl)-3,4- dihydro-4-quinolinones (4a-j) analogs were synthesized by Knoevenagel condensation of a solution of 2-methyl-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl)-3,4-dihydro-4-quinazolinone (3) with aromatic aldehyde in presence of catalytic amount of piperidine. Compounds (4a-j) showed significant biological activity against all the standard strains. All the synthesized compounds were characterized on the basis of their IR, 1H NMR, MASS spectroscopic data and elemental analyses. All the compounds have been tested for antimicrobial and antifungal activity by the cup-plate method.
{"title":"Design, Synthesis, Antibacterial and Antifungal Activity of Novel 2-((E)- 2-aryl-1-ethenyl)-3-(2- sulfanyl-1H-benzo(d)imidazole-5-yl)-3,4- dihydro-4- quinolinones","authors":"Ravinder Nath ANISETTI, M. S. Reddy","doi":"10.1155/2012/795698","DOIUrl":"https://doi.org/10.1155/2012/795698","url":null,"abstract":"The novel 2-[(E)-2-aryl-1-ethenyl]-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl)-3,4- dihydro-4-quinolinones (4a-j) analogs were synthesized by Knoevenagel condensation of a solution of 2-methyl-3-(2-sulfanyl-1H-benzo[d]imidazole-5-yl)-3,4-dihydro-4-quinazolinone (3) with aromatic aldehyde in presence of catalytic amount of piperidine. Compounds (4a-j) showed significant biological activity against all the standard strains. All the synthesized compounds were characterized on the basis of their IR, 1H NMR, MASS spectroscopic data and elemental analyses. All the compounds have been tested for antimicrobial and antifungal activity by the cup-plate method.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/795698","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64353697","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}
CNTs are one of the most significant achievements of nano-technology with important applications in the design of electronic nano-devices. Nano-tubes with small size, physical stability and sensitivity of their electric properties to adsorption of N2 and O2 make them ideal materials for use in gas sensors. In this investigation the (DFT) method is utilized to study the adsorption of oxygen, nitrogen molecules on the surface of (5,0) CNT. The electronic structure, NMR spectrum, dipole moment of nitrogen, oxygen and carbon nuclei's are thoroughly studied. The computational results indicate that rich adsorption patterns may result from the interaction of oxygen and nitrogen with the CNTs. Sometimes, C-O bounds are formed via breaking C-C bounds and sometimes a carbon atom in the nanotube is replaced with an oxygen atom. Sometimes oxygen and nitrogen molecular are attracted to a C-C bound. In summary, the optimized adsorption rates are calculated. The nitrogen molecules adsorb with a comparatively lower rate and almost never a chemical binding is formed with the CNT. Gaussian 98 software has been used to carry out quantum chemistry calculations.
{"title":"Density Functional Theory (DFT) Study of O2, N2 Adsorptions on H-Capped (5, 0) Single–Walled Carbon Nanotube (CNT)","authors":"F. Ashrafi, A. Ghasemi̇","doi":"10.1155/2012/819490","DOIUrl":"https://doi.org/10.1155/2012/819490","url":null,"abstract":"CNTs are one of the most significant achievements of nano-technology with important applications in the design of electronic nano-devices. Nano-tubes with small size, physical stability and sensitivity of their electric properties to adsorption of N2 and O2 make them ideal materials for use in gas sensors. In this investigation the (DFT) method is utilized to study the adsorption of oxygen, nitrogen molecules on the surface of (5,0) CNT. The electronic structure, NMR spectrum, dipole moment of nitrogen, oxygen and carbon nuclei's are thoroughly studied. The computational results indicate that rich adsorption patterns may result from the interaction of oxygen and nitrogen with the CNTs. Sometimes, C-O bounds are formed via breaking C-C bounds and sometimes a carbon atom in the nanotube is replaced with an oxygen atom. Sometimes oxygen and nitrogen molecular are attracted to a C-C bound. In summary, the optimized adsorption rates are calculated. The nitrogen molecules adsorb with a comparatively lower rate and almost never a chemical binding is formed with the CNT. Gaussian 98 software has been used to carry out quantum chemistry calculations.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/819490","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64356181","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}
The chalcone derivatives, 1-(2′-hydroxyaryl)-3-(2-chloroquinolin-3-yl)-prop-2-en-1-one was transformed to corresponding flavone derivatives by iodine impregnated neutral alumina under microwave irradiation. The synthesized flavone derivatives were structurally confirmed by elemental analysis, UV, IR and 1H-NMR spectral data, and the notable yield obtained was compared with previously reported method.
{"title":"Microwave-Induced, Iodine-Alumina Catalyzed Transformations of 1-(2′-hydroxyaryl)-3-(2-chloroquinolin-3-yl)-prop-2-en-1-one","authors":"P. Venkatesan, K. Moorthi","doi":"10.1155/2012/354875","DOIUrl":"https://doi.org/10.1155/2012/354875","url":null,"abstract":"The chalcone derivatives, 1-(2′-hydroxyaryl)-3-(2-chloroquinolin-3-yl)-prop-2-en-1-one was transformed to corresponding flavone derivatives by iodine impregnated neutral alumina under microwave irradiation. The synthesized flavone derivatives were structurally confirmed by elemental analysis, UV, IR and 1H-NMR spectral data, and the notable yield obtained was compared with previously reported method.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/354875","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64315910","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}
Reversed phase-HPLC with fluorescence detection of two major capsaicinoids was described. Isocratic elution using a ratio of methanol and de- ionized water (66:34, v/v) as mobile phase was used at a flow rate of 0.9 mL/min with well achieved separation within 6 min. Under optimum conditions, their analytical figures of merit for the HPLC method were validated. The linearity was in the range of 1.0-25.0 g/mL with multiple determination coefficients of higher than 0.995. The limit of detection was ranged of 0.008-0.01 g/mL. The repeatability and reproducibility of the retention time and peak area for these compounds were in good precision with their relative standard deviations (RSDs) lower than 1% and 5%, respectively. Both capsaicin and dihydrocapsaicin were extracted using an accelerated solvent extraction (ASE) of methanol as an extraction solvent for 5 min static time with 3 cycles. The methanolic extracts were subjected to clean up with C18 solid-phase extraction (SPE) with its recoveries ranking of 90.2-98.0%. The method recoveries of real samples were found to be 60.7-98.6%. The optimized extraction method were applied for the determination of the two capsaicinoids in ten vareities of hot chilli pepper samples. Total contents of capsaicinoids were found in the range of 2,307.0-9047.3 g/g DW with their corresponding Scoville heat unit (SHU) of 34,600-135,700. Additionally, the contents of capsaicinoids using external calibration method comparing with those of standard addition were not significantly different, indicating accuracy of the method. Mostly, the contents of capsaicin found in these real samples were rather higher than those of dihydrocapsaicin.
{"title":"Determination of Capsaicin and Dihydrocapsaicin in Some Chilli Varieties using Accelerated Solvent Extraction Associated with Solid-Phase Extraction Methods and RP-HPLC-Fluorescence","authors":"S. Chanthai, S. Techawongstien","doi":"10.1155/2012/380574","DOIUrl":"https://doi.org/10.1155/2012/380574","url":null,"abstract":"Reversed phase-HPLC with fluorescence detection of two major capsaicinoids was described. Isocratic elution using a ratio of methanol and de- ionized water (66:34, v/v) as mobile phase was used at a flow rate of 0.9 mL/min with well achieved separation within 6 min. Under optimum conditions, their analytical figures of merit for the HPLC method were validated. The linearity was in the range of 1.0-25.0 g/mL with multiple determination coefficients of higher than 0.995. The limit of detection was ranged of 0.008-0.01 g/mL. The repeatability and reproducibility of the retention time and peak area for these compounds were in good precision with their relative standard deviations (RSDs) lower than 1% and 5%, respectively. Both capsaicin and dihydrocapsaicin were extracted using an accelerated solvent extraction (ASE) of methanol as an extraction solvent for 5 min static time with 3 cycles. The methanolic extracts were subjected to clean up with C18 solid-phase extraction (SPE) with its recoveries ranking of 90.2-98.0%. The method recoveries of real samples were found to be 60.7-98.6%. The optimized extraction method were applied for the determination of the two capsaicinoids in ten vareities of hot chilli pepper samples. Total contents of capsaicinoids were found in the range of 2,307.0-9047.3 g/g DW with their corresponding Scoville heat unit (SHU) of 34,600-135,700. Additionally, the contents of capsaicinoids using external calibration method comparing with those of standard addition were not significantly different, indicating accuracy of the method. Mostly, the contents of capsaicin found in these real samples were rather higher than those of dihydrocapsaicin.","PeriodicalId":11519,"journal":{"name":"E-journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2012/380574","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64317871","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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