液质联用测定番茄中甲基硫菌灵残留量

为了评价70％甲基硫菌灵可湿性粉剂在番茄中的使用安全性，开展甲基硫菌灵在番茄中的残留量研究。本文建立了分散固相萃取前处理，高效液相色谱/质谱联用法测定甲基硫菌灵在番茄中残留量的方法。样品经乙腈提取，乙二胺-N-丙基甲硅烷（PSA）和无水硫酸镁混合振荡离心除去杂质和水分，上清液用配有电喷雾（ESI）源的高效液相色谱/质谱联用仪测定。田间试验结果建议在番茄上喷施70％甲基硫菌灵可湿性粉剂562.5 g ai·hm^-2，3次施药，推荐安全间隔期为3 d；市场抽检样品检测表明番茄中甲基硫菌灵的残留量均小于0.05 mg·kg^-1，低于最大残留限量3 mg·kg^-1。

Determination of Thiophanate-methyl in Tamoto by High Performance Liquid Chromatography-triple Quadrupole Tandem Mass Spectometry

To evaluate the safety of use of 70%thiophanate-methyl wettable powders in tomato, a supervised trial experiment was conducted to study the residues in tomato. A method of determining thiophanate-methyl by high performance liquid chromatography-tandem mass spectrometry（LC-MSMS）was established. Acetonitrile was used as an extraction solvent, and PSA and anhydrous magnesium were used for sample purifying. Samples were determined and quantified by LC-MSMS in the multiple reaction monitoring mode（MRM）. The field trial rec-ommended spraying 70%thiophanate-methyl WP on tomato with 562.5 g ai·hm^-2 in three times, which the safe interval was not less than three days from the last time to harvest. The results showed that the thiophanate methyl residue in tomato was lower than 0.05 mg·kg^-1, both from field trials and market sampling samples.