A simple, sensitive and cost effective method is reported for the analysis of herbicides by LC-MS/MS with positive spray ionization technique. The limit iof quantification (LOQ) was 0.001 mg kg~(-1) for pretilachlor and pyrazosulfuron ethyl, 0.002 mg kg 1 for pendimethalin and 0.003 mg kg~(-1) for bispyribac sodium The calibration curve for each herbicide was linear over the concentration range of 0.01 to 0.1 ug mL~(-1) and coefficient of determination (R2) was 0.999. Sample extraction was done following the modified QuEChERS technique which recorded recovery within acceptable range of 70~(-1)20 per cent for all the herbicides. Residual analysis of the four herbicides following application of pendimethalin, pretilachlor and pyrazosulfuron ethyl (pre-emergent) and bispyribac sodium (post-emergent) in field samples revealed no significant difference between surface drip irrigation and sub-surface drip irrigation systems. Among the treatments, pyrazosulfuron ethyl 10 per cent WP applied at 20 g a.i ha~(-1) followed by bispyribac sodium 10 per cent SL at 25 g a.i ha~(-1) recorded the residue of pyrazosulfuron ethyl only in surface and sub-surface drip systems, respectively during 2016 and 2017. Pendimethalin 38.7 per cent CS recorded residues below detectable level; whereas pretilachlor 50 per cent EC applied at 1.0 kg a.i ha~(-1) did not record any residues in surface and sub-surface drip irrigation systems.
展开▼
机译：报道了一种简单、灵敏且具有成本效益的方法，用于采用正喷雾电离技术通过LC-MS/MS分析除草剂。丙草胺和吡唑磺隆乙酯的限量iof定量（LOQ）为0.001 mg kg~（-1），戊甲灵为0.002 mg kg 1，双草胺钠为0.003 mg kg~（-1），每种除草剂的校准曲线在0.01-0.1 ug mL~（-1）浓度范围内呈线性，决定系数（R2）为0.999。样品提取采用改良的QuEChERS技术进行，所有除草剂的回收率均在70~（-1）20%的可接受范围内。在田间样品中施用二甲戊灵、丙草胺和吡唑磺隆乙基（出苗前）和双草胺钠（出苗后）后对四种除草剂的残留分析表明，地表滴灌和地下滴灌系统之间没有显着差异。其中，2016年和2017年，在20 g a.i ha~（-1）下施用吡唑磺隆乙酯10%可湿性剂，在25 g a.i ha~（-1）下施用10%双草胺酸钠，分别记录了吡唑磺隆乙基在地表和地下滴水系统中的残留量。二甲戊灵38.7%CS记录的残留物低于可检测水平;而在1.0 kg a.i ha~（-1）下施用50%丙草胺的乳油在地表和地下滴灌系统中没有记录任何残留物。
展开▼
