Confirmation and quantification of pesticide residues by mass spectrometry

The sensitivity and specificity of mass spectrometry makes this an attractive technique for the confirmation and quantification of trace levels of pesticide residues. Two applications of mass spectrometry are outlined, that of combined headspace gas chromatography (g.c.)/mass spectrometry (m.s.), for the analysis of volatile fumigants such as ethylene dibromide (EDB) in imported fruits and multi-residue halogenated compounds in bran products, and that of quantitative g.c./m.s. for the determination of a range of organochlorine pesticide residues. The approach to setting-up a capillary g.c. multiple ion monitoring programme is described, with emphasis on quantitative aspects, and in particular the use of stable isotope internal standards. This is illustrated with an example of the quantification of organochlorine pesticide residues in eggs.     

非衍生化超高效液相色谱-串联质谱法快速检测环境水中强极性农药及其代谢物

建立了一种简便、直接进样、非衍生化超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定环境水样中乙烯利、草甘膦、草铵膦及其代谢物等6种强极性化合物残留的分析检测方法。环境水样经离心、过滤后,无需衍生,直接进样进行定量分析。样品经Waters Acquity UPLC HSS T3色谱柱(100 mm×2.1 mm,1.8μm)分离,以0.1%甲酸-5μmol/L亚甲基二膦酸水溶液、甲醇为流动相,在电喷雾离子源、正离子扫描和多反应监测模式(MRM)下进行分析,外标法定量。结果表明：6种化合物在各自线性范围内具有良好的线性关系,决定系数(R²)均大于0.99,在10～200μg/L添加水平下,6种化合物在环境水样中的平均回收率在75%～100%之间,日内相对标准偏差与日间相对标准偏差(n=6)分别为3.6%～7.0%和4.3%～7.5%。方法定量限在0.5～10.0μg/L之间。利用所建立的方法对3个地区10份地表水样进行检测。结果显示：乙烯利、草甘膦、草铵膦及其代谢物等6种化合物均未检出。该方法与衍生化方法相比,具有简便快速、重现性好、灵敏度高等优点,可以为环境...     

气相色谱-串联质谱法测定葡萄中78种农药残留的定量校准方法评估

以柠檬酸盐缓冲体系的QuEChERS方法为前处理方法,气相色谱-串联质谱联用仪为检测仪器,建立了葡萄中78种农药残留的检测方法.采用添加回收法评估了葡萄中4种基质匹配校准方法的定量结果,评估了4种校准方法的线性回归系数、回收率和精密度.结果表明:在添加回收试验中,当添加水平为0.01 mg/kg时,在0.005～～0....     

Simultaneous estimation of bioresmethrin and piperonyl butoxide by gas-liquid chromatography with chemical-ionisation mass spectrometry

A technique using gas-liquid chromatography combined with chemical-ionisation mass spectrometry is described for the simultaneous quantitative measurement of bioresmethrin and piperonyl butoxide. It is sensitive to 0.2 ng bioresmethrin and 2 ng piperonyl butoxide. The amounts of these compounds, in extracts of 50-g samples of laboratory-fortified wheat, were determined.     

高效液相色谱-串联四级杆质谱测定黄瓜和土壤中乙嘧酚磺酸酯的残留

建立了高效液相色谱-串联四级杆质谱测定黄瓜和土壤中的乙嘧酚磺酸酯的农药残留方法,样品经乙腈提取,氨基柱净化,应用高效液相色谱-串联四极杆质谱仪进行测定,外标法定量。采用该法对黄瓜和土壤中的乙嘧酚磺酸酯农药进行测定,平均回收率为93.69～104.93%之间,相对标准偏差为3.42～7.47%,检出限为0.001 6mg/kg,线性范围为5～320ng/mL,相关系数为0.999 5.结果表明：该法可用于黄瓜和土壤中乙嘧酚磺酸酯的测定。     

Recent applications of chromatography for analysis of contaminants in cannabis products: a review

In the last few years, the cultivation of cannabis has been increasing due to greater use in foods, recreational use, creams, oils, and other applications. Thus, analysis of contaminants (e.g. pesticides and mycotoxins) in cannabis products is necessary to ensure consumer safety. This review is focused on the analytical procedures, based on chromatographic techniques, used for the determination of contaminants in cannabis and related products, developed from 2015 to 2020. QuEChERS (acronym of quick, easy, cheap, effective, rugged and safe) was mainly used for the extraction of pesticides and other contaminants from cannabis because its versatility and capacity to extract a wide range of substances, and therefore, increasing the scope of the analysis. The most employed technique to determine pesticides and mycotoxins in cannabis products was liquid chromatography (LC) coupled to mass spectrometry (MS), although gas chromatography (GC) coupled to MS was also employed for the analysis of non-polar compounds, using triple quadrupole (QqQ) as mass analyzer. Nevertheless, new advances in cannabis analysis are also discussed, introducing techniques such as high-resolution mass spectrometry (HRMS), which allows for performing both targeted and untargeted (unknown and suspect) analyses. © 2021 Society of Chemical Industry.     

核磁共振法测定甲哌鎓原药的含量

采用定量核磁共振法建立了甲哌鎓原药的定量方法。以重水为溶剂,仲丁基脲为内标物,以化学位移分别在δ3.12的甲哌鎓甲基和δ1.10的仲丁基脲甲基的1H-NMR信号作为定量峰。以甲哌鎓与仲丁基脲定量峰的峰面积比(AS/AI)对甲哌鎓与仲丁基脲的质量比(WS/WI)进行线性回归,线性相关系数为0.999 9;重复测定同一批次原药含量,变异系数为0.28%。采用核磁共振波谱法对甲哌鎓进行定量分析,操作简便,测定速度快,准确度高。     

Alternate pathways of metribuzin metabolism in soybean: Formation of N-glucoside and homoglutathione conjugates

Metribuzin [4-amino-6-tert-butyl-3(methylthio)-1,2,4-triazin-5(4H)-one] metabolism was studied in soybean [Glycine max (L.) Merr. Tracy]. Pulse treatment studies with seedlings and excised mature leaves showed that [5-¹⁴C]metribuzin was absorbed rapidly and translocated acropetally. In seedlings, >97% of the root-absorbed ¹⁴C was present in foliar tissues after 24 hr. In excised leaves, 50–60% of the absorbed ¹⁴C remained as metribuzin 48 hr after pulse treatment, 12–20% was present as polar metabolites, and 20–30% was present as an insoluble residue. Metabolites were isolated by solvent partitioning, and were purified by adsorption, ion-exchange, thin-layer, and high-performance liquid chromatography. The major metabolite (I) was identified as a homoglutathione conjugate, 4-amino-6-tert-butyl-3-S-(γ-glutamyl-cysteinyl-β-alanine)-1,2,4-triazin-5(4H)-one. Metabolite identification was confirmed by qualitative analysis of amino acid hydrolysis products, fast atom bombardment (FAB), and chemical ionization (CI) mass spectrometry, and by comparison with a reference glutathione conjugate synthesized in vitro with a hepatic microsomal oxidase system from rat. Minor metabolites were identified as an intermediate N-glucoside conjugate (II), a malonyl N-glucoside conjugate (III), and 4-malonylamido-6-tert-butyl-1,2,4-triazin-3,5(2H,4H)-dione (N-malonyl DK, IV) by CI and FAB mass spectrometry. Alternative pathways of metribuzin metabolism are proposed.     

叶菌唑95%原药气相色谱分析方法研究

本文采用毛细管气相色谱法,以二十二烷为内标,HP-5毛细管柱和氢火焰离子化检测器,对叶菌唑原药进行分离和定量分析。结果表明,该分析方法的线性相关系数为0.999 4,标准偏差为0.32,变异系数为0.33%,平均回收率为100.45%。     

肟菌酯气相色谱分析方法研究

采用气相色谱法,用DB-1毛细管柱,以邻苯二甲酸二环己酯为内标物,用氢火焰离子化检测器对肟菌酯原药进行定量检测。在选定的色谱条件下,有效成分、内标物、杂质能得到有效分离。结果表明,肟菌酯在一定浓度下的线性相关系数为0.999 9,标准偏差为0.13,变异系数为0.13%,平均回收率为99.68%。     

硝虫硫磷原药气相色谱分析

本文介绍了采用气相色谱法用HP-5毛细管柱,以邻苯二甲酸二丁酯为内标物,氢火焰离子化检测器对硝虫硫磷原药进行定量分析。结果表明,该分析方法的线性相关系数为0.999 9,平均回收率为99.63%,标准偏差为0.14,变异系数为0.14%。     

炔草酯原药气相色谱分析方法研究

本文介绍了采用气相色谱法用HP-5（30m×0.32mm×0.25μm）毛细管柱,以邻苯二甲酸二环乙酯为内标物,以氢火焰离子化检测器对除草剂炔草酯原药进行定性定量分析。结果表明,该分析方法的线性相关系数为1.000,标准偏差为0.24,变异系数为为0.60%,平均回收率为99.98%。     

乙丁烯氟灵原药的气相色谱分析方法研究

本文采用气相色谱法,试样用丙酮为溶解,以邻苯二甲酸二异丁酯为内标物,使用DB-5毛细管柱和氢火焰离子化检测器对试样中乙丁烯氟灵进行分离和定量分析。结果表明乙丁烯氟灵线性相关系数为0.999 9;标准偏差为0.24,变异系数为0.25%;平均回收率99.9%。     

Determination of chlormequat residues in cotton seed by gas chromatography

A simple and sensitive method to determine chlormequat (chlorocholine chloride) residues in plant tissue has been devised. The technique is based on an in-vitro multi-step reaction where chlormequat is initially N-demethylated with potassium pentafluorothiophenolate followed by a further reaction with excess reagent to produce a pentafluorothiophenyl derivative. Electron capture detection and mass spectrometry were used for quantitative determination and identification. The method was applied to the analysis of cotton seed harvested from cotton plants treated with various concentrations of chlormequat.     

Residues of the herbicide fenoxaprop‐P‐ethyl,its agronomic safener isoxadifen‐ethyl and their metabolites in rice after field application

BACKGROUND: Fenoxaprop‐P‐ethyl is a herbicide used on cereals and in particular on rice, the degradation of which leads to several relevant metabolites. The herbicide is used together with an agronomic safener such as isoxadifen‐ethyl, which also generates some metabolites. The present work was aimed at developing and validating an analytical method for the determination of the above parent compounds and their main metabolites in the edible fractions of rice. Parent compounds were extracted in acetonitrile and determined by gas chromatography with a mass spectrometer detector, while metabolites were extracted in acetonitrile and analysed by liquid chromatography tandem mass spectrometry. RESULTS: The method was validated through recovery tests in rice straw, grain and plant: accuracy was in the range 76–86% and 90–103% for parent compounds and metabolites respectively. Precision, as relative standard deviation, was in the range 3–11% and 6–17% for parent compounds and metabolites respectively. The limit of detection was 0.01 mg kg^?1 for each analyte, while the limit of quantification was set at 0.05 mg kg^?1. CONCLUSION: The analytical method is suitable for quantitative determination of each analyte considered in rice commodities. Copyright © 2010 Society of Chemical Industry     

食品分析水平测试计划农药残留能力验证中分析方法的选择及其结果评价

通过确认可靠的分析方法和手段,对FAPAS(食品分析水平测试计划)能力验证样品中的农药组份进行了定性及定量检测。首先通过色-质联用技术对样品中可能含有的农药组份进行快速定性筛选,确定目标化合物,再综合考虑样品中干扰物的主要成分和目标化合物的特性,运用合适的前处理技术和检测方法对目标化合物进行定量分析。在6项FAPAS能力验证中,所有参数的|Z|值均小于2,结果均为满意。     

氨氟乐灵原药气相色谱分析方法

采用气相色谱法分析氨氟乐灵原药含量。以正二十二烷为内标物,SE-30石英毛细管柱分离,氢火焰离子化检测器检测。在选定的色谱条件下,有效成分、内标物及杂质能得到有效分离,并能获得较好的检测效果。分析结果表明,氨氟乐灵的线性相关系数为0.999 9,回收率为99.2%～100.6%,变异系数为0.22%。     

苦参碱毛细管柱气相色谱法分析

本文介绍了用HP-5毛细管柱，以邻苯二甲酸二正戊酯为内标，对苦参碱进行定量分析的方法。结果表明方法的线性相关系数为0．9999，回收率为99．6％～101．1％，变异系数为0．87％。     

增效醚的气相色谱分析方法

本文针对卫生杀虫领域中常用的增效剂－增效醚,采用气相色谱法,以邻苯二甲酸二辛酯为内标,ＳＥ－３０为填充柱,在适当操作条件下进行定量分析,其方法的变异系数为０．３％,平均回收率１００．９８％,线性相关系数为０．９９８６。     

基于改良QuEChERS-气相色谱-串联质谱法测定禽蛋中53种农药残留

基于改良QuEChERS前处理方法结合气相色谱-串联质谱 (GC-MS/MS),建立了禽蛋中53种农药残留的检测方法。样品用乙酸乙酯提取,经弗罗里硅土和硅藻土净化,用GC-MS/MS分析。采用HP-5MS柱进行分离,电子轰击离子源 (EI) 动态多反应监测模式 (dMRM) 检测,以空白基质匹配标准溶液外标法定量。结果表明:经方法验证,53种农药的仪器检出限 (LOD) 在0.000 25~0.005 mg/L之间,方法定量限 (LOQ) 在0.000 5~0.01 mg/kg之间,相关系数 (r)在0.996 7~1之间;在LOQ、2 LOQ和10 LOQ 3个添加水平下,53种农药在鸡蛋中的平均回收率在76%~104%之间,相对标准偏差在0.090%~14%之间 (n = 6)。该方法前处理快速、检测方法灵敏、准确,在禽蛋中有机氯和有机磷等农药多残留检测中具有较好的应用前景。