Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic me...Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.展开更多
Tyrosine kinase inhibitors(TKIs)have emerged as the first-line small molecule drugs in many cancer therapies,exerting their effects by impeding aberrant cell growth and proliferation through the modulation of tyrosine...Tyrosine kinase inhibitors(TKIs)have emerged as the first-line small molecule drugs in many cancer therapies,exerting their effects by impeding aberrant cell growth and proliferation through the modulation of tyrosine kinase-mediated signaling pathways.However,there exists a substantial inter-individual variability in the concentrations of certain TKIs and their metabolites,which may render patients with compromised immune function susceptible to diverse infections despite receiving theoretically efficacious anticancer treatments,alongside other potential side effects or adverse reactions.Therefore,an urgent need exists for an up-to-date review concerning the biological matrices relevant to bioanalysis and the sampling methods,clinical pharmacokinetics,and therapeutic drug monitoring of different TKIs.This paper provides a comprehensive overview of the advancements in pretreatment methods,such as protein precipitation(PPT),liquid-liquid extraction(LLE),solid-phase extraction(SPE),micro-SPE(μ-SPE),magnetic SPE(MSPE),and vortex-assisted dispersive SPE(VA-DSPE)achieved since 2017.It also highlights the latest analysis techniques such as newly developed high performance liquid chromatography(HPLC)and high-resolution mass spectrometry(HRMS)methods,capillary electrophoresis(CE),gas chromatography(GC),supercritical fluid chromatography(SFC)procedures,surface plasmon resonance(SPR)assays as well as novel nanoprobes-based biosensing techniques.In addition,a comparison is made between the advantages and disadvantages of different approaches while presenting critical challenges and prospects in pharmacokinetic studies and therapeutic drug monitoring.展开更多
Background Water deficit is an important problem in agricultural production in arid regions.With the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting m...Background Water deficit is an important problem in agricultural production in arid regions.With the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting mode could achieve high yield,fiber quality and water use efficiency(WUE).This study aimed to explore if chemical topping affected cotton yield,quality and water use in relation to row configuration and plant densities.Results Experiments were carried out in Xinjiang China,in 2020 and 2021 with two topping method,manual topping and chemical topping,two plant densities,low and high,and two row configurations,i.e.,76 cm equal rows and 10+66 cm narrow-wide rows,which were commonly applied in matching harvest machine.Chemical topping increased seed cotton yield,but did not affect cotton fiber quality comparing to traditional manual topping.Under equal row spacing,the WUE in higher density was 62.4%higher than in the lower one.However,under narrow-wide row spacing,the WUE in lower density was 53.3%higher than in higher one(farmers’practice).For machine-harvest cotton in Xinjiang,the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m-2 or equal rows with 18 plants m-2.Conclusion The plant density recommended in narrow-wide rows was less than farmers’practice and the density in equal rows was moderate with local practice.Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.展开更多
Adulteration may consist in non authorized source of nitrogen addition to increase the protein content of some raw materials. Urea which is authorized for feed is a non nutritional source of nitrogen in food and pet f...Adulteration may consist in non authorized source of nitrogen addition to increase the protein content of some raw materials. Urea which is authorized for feed is a non nutritional source of nitrogen in food and pet food. Adulteration of food or pet food raw material by urea is thus monitored by manufacturer and governmental authorities with official methods which are either enzymatic (Association of Official Agricultural Chemists, AOAC) or spectro-colorimetric (European Community, EC). Each method gives results which are not comparable and spectro-colorimetric methods may result in false-positive urea detection. Liquid chromatographic (LC/UV-DAD) analysis of extracts from spectro-colorimetric method indicates that presence of free amino-acid may interfere with colorimetric detection of urea in the EC method with pet food samples. Liquid chromatography electrospray ionization high resolution mass spectrometry (LC/ESI-HRMS) has allowed to quantify low content (<0.01%) of urea in pet food water extracts for samples which resulted in significant urea detection with colorimetric method and in content below the detection threshold with enzymatic method. This study demonstrates the EC colorimetric method is not applicable to pet food and also food samples which have a complex composition with significant levels of free amino acids. On the other hand we clearly evidenced by means of the LC/ESI-HRMS results that the AOC Enzymatic method is applicable to urea quantification in pet food samples and gives reliable results.展开更多
采用同位素稀释高分辨气相色谱-高分辨质谱法(isotope dilution high resolution gas chromatography and high resolution mass spectrometry,ID-HRGC-HRMS)测定土壤样品中二恶英类化合物(polychlorinated dibenzo-p-dioxins and diben...采用同位素稀释高分辨气相色谱-高分辨质谱法(isotope dilution high resolution gas chromatography and high resolution mass spectrometry,ID-HRGC-HRMS)测定土壤样品中二恶英类化合物(polychlorinated dibenzo-p-dioxins and dibenzofurans,PCDD/Fs)的等价毒性当量(toxic equivalent quantity,TEQ)。讨论并确定了测定土壤样品中二恶英类化合物2,3,7,8位异构体不确定度的来源并合成了各异构体的相对标准不确定度;在此基础上,计算了3种等价毒性当量因子(toxic equivalent factor,TEF)框架下土壤样品中PCDD/Fs的TEQ浓度及其合成不确定度和扩展不确定度。展开更多
酶联免疫法(enzyme immunoassay method,EIA)作为一种二口恶英物质的半定量筛选方法被越来越多的实验室使用。与经典的高分辩气相色谱-高分辨质谱法(high-resolution gas chromatrography coupled with high-resolution mass spectromet...酶联免疫法(enzyme immunoassay method,EIA)作为一种二口恶英物质的半定量筛选方法被越来越多的实验室使用。与经典的高分辩气相色谱-高分辨质谱法(high-resolution gas chromatrography coupled with high-resolution mass spectrometry,HRGC-HRMS)不同,ELISA方法得到检测样本总二口恶英类物质的含量,两种方法之间存在偏差。文章引入校正调节因子(calibration adjustment factor,CAF)来减少这种偏差。通过对本实验室前期工作中得到的47组土壤样品二口恶英数据进行统计分析,计算得到土壤来源二口恶英EIA检测方法的校正调节因子为0.6。后期实验室进行崇明岛土壤二口恶英水平研究时,对得到的土壤样品EIA检测结果使用本文得到的CAF值进行校正,验证CAF值的作用。校正前,两组数据之间存在显著性差异,校正后,数据相近,且无显著性差异。证明此CAF值在土壤样品中的适用性。展开更多
文摘Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.
基金supported by the Natural Science Foundation of Liaoning Province,China(Grant No.:2023-MS-172).
文摘Tyrosine kinase inhibitors(TKIs)have emerged as the first-line small molecule drugs in many cancer therapies,exerting their effects by impeding aberrant cell growth and proliferation through the modulation of tyrosine kinase-mediated signaling pathways.However,there exists a substantial inter-individual variability in the concentrations of certain TKIs and their metabolites,which may render patients with compromised immune function susceptible to diverse infections despite receiving theoretically efficacious anticancer treatments,alongside other potential side effects or adverse reactions.Therefore,an urgent need exists for an up-to-date review concerning the biological matrices relevant to bioanalysis and the sampling methods,clinical pharmacokinetics,and therapeutic drug monitoring of different TKIs.This paper provides a comprehensive overview of the advancements in pretreatment methods,such as protein precipitation(PPT),liquid-liquid extraction(LLE),solid-phase extraction(SPE),micro-SPE(μ-SPE),magnetic SPE(MSPE),and vortex-assisted dispersive SPE(VA-DSPE)achieved since 2017.It also highlights the latest analysis techniques such as newly developed high performance liquid chromatography(HPLC)and high-resolution mass spectrometry(HRMS)methods,capillary electrophoresis(CE),gas chromatography(GC),supercritical fluid chromatography(SFC)procedures,surface plasmon resonance(SPR)assays as well as novel nanoprobes-based biosensing techniques.In addition,a comparison is made between the advantages and disadvantages of different approaches while presenting critical challenges and prospects in pharmacokinetic studies and therapeutic drug monitoring.
基金Key Research and Development Program of Xinjiang(2022B02001-1)National Natural Science Foundation of China(42105172,41975146).
文摘Background Water deficit is an important problem in agricultural production in arid regions.With the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting mode could achieve high yield,fiber quality and water use efficiency(WUE).This study aimed to explore if chemical topping affected cotton yield,quality and water use in relation to row configuration and plant densities.Results Experiments were carried out in Xinjiang China,in 2020 and 2021 with two topping method,manual topping and chemical topping,two plant densities,low and high,and two row configurations,i.e.,76 cm equal rows and 10+66 cm narrow-wide rows,which were commonly applied in matching harvest machine.Chemical topping increased seed cotton yield,but did not affect cotton fiber quality comparing to traditional manual topping.Under equal row spacing,the WUE in higher density was 62.4%higher than in the lower one.However,under narrow-wide row spacing,the WUE in lower density was 53.3%higher than in higher one(farmers’practice).For machine-harvest cotton in Xinjiang,the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m-2 or equal rows with 18 plants m-2.Conclusion The plant density recommended in narrow-wide rows was less than farmers’practice and the density in equal rows was moderate with local practice.Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.
文摘Adulteration may consist in non authorized source of nitrogen addition to increase the protein content of some raw materials. Urea which is authorized for feed is a non nutritional source of nitrogen in food and pet food. Adulteration of food or pet food raw material by urea is thus monitored by manufacturer and governmental authorities with official methods which are either enzymatic (Association of Official Agricultural Chemists, AOAC) or spectro-colorimetric (European Community, EC). Each method gives results which are not comparable and spectro-colorimetric methods may result in false-positive urea detection. Liquid chromatographic (LC/UV-DAD) analysis of extracts from spectro-colorimetric method indicates that presence of free amino-acid may interfere with colorimetric detection of urea in the EC method with pet food samples. Liquid chromatography electrospray ionization high resolution mass spectrometry (LC/ESI-HRMS) has allowed to quantify low content (<0.01%) of urea in pet food water extracts for samples which resulted in significant urea detection with colorimetric method and in content below the detection threshold with enzymatic method. This study demonstrates the EC colorimetric method is not applicable to pet food and also food samples which have a complex composition with significant levels of free amino acids. On the other hand we clearly evidenced by means of the LC/ESI-HRMS results that the AOC Enzymatic method is applicable to urea quantification in pet food samples and gives reliable results.
文摘采用同位素稀释高分辨气相色谱-高分辨质谱法(isotope dilution high resolution gas chromatography and high resolution mass spectrometry,ID-HRGC-HRMS)测定土壤样品中二恶英类化合物(polychlorinated dibenzo-p-dioxins and dibenzofurans,PCDD/Fs)的等价毒性当量(toxic equivalent quantity,TEQ)。讨论并确定了测定土壤样品中二恶英类化合物2,3,7,8位异构体不确定度的来源并合成了各异构体的相对标准不确定度;在此基础上,计算了3种等价毒性当量因子(toxic equivalent factor,TEF)框架下土壤样品中PCDD/Fs的TEQ浓度及其合成不确定度和扩展不确定度。
文摘酶联免疫法(enzyme immunoassay method,EIA)作为一种二口恶英物质的半定量筛选方法被越来越多的实验室使用。与经典的高分辩气相色谱-高分辨质谱法(high-resolution gas chromatrography coupled with high-resolution mass spectrometry,HRGC-HRMS)不同,ELISA方法得到检测样本总二口恶英类物质的含量,两种方法之间存在偏差。文章引入校正调节因子(calibration adjustment factor,CAF)来减少这种偏差。通过对本实验室前期工作中得到的47组土壤样品二口恶英数据进行统计分析,计算得到土壤来源二口恶英EIA检测方法的校正调节因子为0.6。后期实验室进行崇明岛土壤二口恶英水平研究时,对得到的土壤样品EIA检测结果使用本文得到的CAF值进行校正,验证CAF值的作用。校正前,两组数据之间存在显著性差异,校正后,数据相近,且无显著性差异。证明此CAF值在土壤样品中的适用性。
