气相色谱-串联质谱同位素内标法测定果蔬食品中有机锡类农药残留

Determination of Organotin Pesticide Residues in Fruits and Vegetables by Gas Chromatography-tandem Mass Spectrometry with Isotope-labeled Internal Standards

摘要:

建立气相色谱-串联质谱同位素内标法测定蔬菜水果中三环锡、三唑锡、薯瘟锡、毒菌锡和苯丁锡等有机锡类农药残留的分析检测方法。样品经过1%冰醋酸-乙腈溶液提取，四乙基硼化钠衍生后用PC/NH2-SPE固相萃取柱净化，使用正己烷-丙酮（99:1，V/V）洗脱，采用EI源进行测定。结果表明，在0.05~1.00 mg/L质量浓度范围内，3种有机锡类农药呈良好线性，相关系数均在0.998以上，在0.04、0.10、0.20 mg/kg三个添加水平下，阴性样品中有机锡的回收率范围在81.64%~106.23%，相对标准偏差（RSD）均小于6.33%（n=6）。三环锡、薯瘟锡和苯丁锡的方法定量限分别为0.01、0.009和0.039 mg/kg。该方法稳定可靠，灵敏度高，可用于水果蔬菜等农产品中有机锡类农药的测定，并对其他食品中有机锡类农药的测定方法提供了参考依据。

Abstract:

A gas chromatography-tandem mass spectrometric (GC-MS/MS) method with isotope-labeled internal standards was developed for the determination of organotin pesticide residues such as cyhexatin, azocylotin, fentin-acetate, triphenyltin hydroxide and fenbutatin oxide in vegetables and fruits. Samples were extracted with 1% glacial aceticacid-acetonitrile, derivatized with sodium tetraethyl borate, purified with a PC/NH2-SPE column, eluted with n-hexane-acetone (99:1, V/V), and determined using an EI source. The results showed that good linearity was found in the concentration range of 0.05~1.00 mg/L for the determination of the three organotin pesticides, with all the correlation coefficients higher than 0.998. The recovery rates of organotin ranges in the negative samples spiked at the three levels (0.04, 0.10 and 0.20 mg/kg) ranged from 81.64% to 106.23%, with the relative standard derivations (RSDs) all lower than 6.33% (n=6). The limits of quantification (LOQ) of the proposed method for cyhexatin, fentin-acetate, and fenbutatin oxide were 0.01, 0.009 and 0.039 mg/kg, respectively. This method is stable, reliable and highly sensitive, thereby suitable for the determination of organotin pesticide residues in agricultural products such as fruits and vegetables. This method also provides a reference for the determination of organotin pesticide residues in other foods.