To effectively assess the extent of the mycotoxin contamination of grapes,a method was developed to analyze 22 mycotoxins by ultra-high-performance liquid chromatography coupled with quadrupole/orbitrap high-resolutio...To effectively assess the extent of the mycotoxin contamination of grapes,a method was developed to analyze 22 mycotoxins by ultra-high-performance liquid chromatography coupled with quadrupole/orbitrap high-resolution mass spectrometry(UPLC-Q-Orbitrap HRMS).Samples were extracted and purified using the QuEChERS(quick,easy,cheap,effective,rugged,and safe)procedure.The extracts were separated on a BEH Shield C18 column(100 mm×2.1 mm,1.7μm),using methanol and water with 0.1%formic acid solution and 2 mmol/L ammonium acetate as the mobile phases.The quantification was performed according to a matrix-matched external standard method.There was a good linear relationship within the respective mass concentration ranges of 22 mycotoxins;the correlation coefficients were not less than 0.9981.The limit of quantification was 0.3-10.0μg/kg.Mycotoxin recovery ranged from 68.6%to 109.0%,with a relative standard deviation of 1.28%-12.80%.The method is simple,rapid,highly sensitive,and accurate,making it useful for screening grapes for common and emerging mycotoxins.展开更多
A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and a...A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and alumina clean up of PCDD/Fs in soil was achieved by accelerated solvent extractor.Then the multi-layer silica-gel column was used for further clean up.The whole method has been evaluated on certified reference soil and farm soil.Accuracy and precision of this method was tested with satisfactory results.展开更多
The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of ...The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.展开更多
基金supported by Science and Technology Program of the State Administration for Market Regulation of China (2020MK014).
文摘To effectively assess the extent of the mycotoxin contamination of grapes,a method was developed to analyze 22 mycotoxins by ultra-high-performance liquid chromatography coupled with quadrupole/orbitrap high-resolution mass spectrometry(UPLC-Q-Orbitrap HRMS).Samples were extracted and purified using the QuEChERS(quick,easy,cheap,effective,rugged,and safe)procedure.The extracts were separated on a BEH Shield C18 column(100 mm×2.1 mm,1.7μm),using methanol and water with 0.1%formic acid solution and 2 mmol/L ammonium acetate as the mobile phases.The quantification was performed according to a matrix-matched external standard method.There was a good linear relationship within the respective mass concentration ranges of 22 mycotoxins;the correlation coefficients were not less than 0.9981.The limit of quantification was 0.3-10.0μg/kg.Mycotoxin recovery ranged from 68.6%to 109.0%,with a relative standard deviation of 1.28%-12.80%.The method is simple,rapid,highly sensitive,and accurate,making it useful for screening grapes for common and emerging mycotoxins.
文摘A rapid pretreatment method of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in soil and analysis by high resolution gas chromatograph-high resolution mass spectrometry was present.The extraction and alumina clean up of PCDD/Fs in soil was achieved by accelerated solvent extractor.Then the multi-layer silica-gel column was used for further clean up.The whole method has been evaluated on certified reference soil and farm soil.Accuracy and precision of this method was tested with satisfactory results.
基金the Minas Gerais State Science Foundation(FAPEMIG)-process APQ-00918-13the Brazilian National Research Council(CNPq)-process 473893-2013-1 for their financial support and the granting of research fellowships.
文摘The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.
