Zhang Yun, Wang Kai, Wu Junxue, Zhang Hongyan
College of Science, China Agricultural University, Beijing 100193, China.
Int J Anal Chem. 2014;2014:256091. doi: 10.1155/2014/256091. Epub 2014 Oct 13.
A simple analytical method was developed to measure concentrations of glufosinate ammonium and its metabolites, 3-methylphosphinico-propionic acid (MPP) and 2-methylphosphinico-acetic acid (MPA), in field soil samples. To determine the minimum quantification limit, samples were spiked at different levels (0.1, 0.5, and 1.0 mg/kg). Soil samples were extracted with ammonium hydroxide solution 5% (v/v), concentrated, and reacted with trimethyl orthoacetate (TMOA) in the presence of acetic acid for derivatization. The derivatives were quantified by gas chromatography (GC) using a flame photometric detector (FPD). The linear correlation coefficients of glufosinate ammonium, MPP, and MPA in soil were 0.991, 0.999, and 0.999, respectively. The recoveries of this method for glufosinate ammonium, MPP, and MPA in soil were 77.2-95.5%, 98.3-100.3%, and 99.3-99.6% with relative standard deviations (RSD) of 1.8-4.1%, 0.4-1.4%, and 1.3-2.0%, respectively. Glufosinate ammonium dissipated rapidly in soil to MPA in hours and gradually degraded to MPP. The half-life of glufosinate ammonium degradation in soil was 2.30-2.93 days in an open field. In soil samples stored at -20°C glufosinate ammonium was stable for two months. The results of this study should provide guidance for the safe application of the herbicide glufosinate ammonium to agricultural products and the environment.
开发了一种简单的分析方法，用于测定田间土壤样品中草铵膦及其代谢产物3-甲基膦酰基丙酸（MPP）和2-甲基膦酰基乙酸（MPA）的浓度。为确定最低定量限，将样品添加不同水平（0.1、0.5和1.0 mg/kg）的标准品。土壤样品用5%（v/v）氢氧化铵溶液萃取、浓缩，并在乙酸存在下与原乙酸三甲酯（TMOA）反应进行衍生化。衍生物通过配备火焰光度检测器（FPD）的气相色谱（GC）进行定量。土壤中草铵膦、MPP和MPA的线性相关系数分别为0.991、0.999和0.999。该方法对土壤中草铵膦、MPP和MPA的回收率分别为77.2 - 95.5%、98.3 - 100.3%和99.3 - 99.6%，相对标准偏差（RSD）分别为1.8 - 4.1%、0.4 - 1.4%和1.3 - 2.0%。草铵膦在土壤中数小时内迅速降解为MPA，并逐渐降解为MPP。在开阔田间，草铵膦在土壤中的降解半衰期为2.30 - 2.93天。在-20°C储存的土壤样品中，草铵膦在两个月内保持稳定。本研究结果应为草铵膦除草剂在农产品和环境中的安全应用提供指导。
