三甲基硅重氮甲烷衍生化-气相色谱法测定水果蔬菜中乙烯利的残留

针对水果蔬菜中乙烯利的残留，建立了三甲基硅重氮甲烷衍生化-气相色谱的分析方法。样品用 V (甲醇) : V (盐酸) = 9:1的溶液提取，无水乙醚萃取，三甲基硅重氮甲烷衍生化15 min，采用气相色谱-质谱法定性，气相色谱仪-火焰光度检测器 (GC-FPD) 检测，外标法定量。结果显示:在0.01~2 mg/L范围内，乙烯利的质量浓度与其对应的峰面积间线性关系良好，相关系数大于0.999 6；此方法检出限为0.01 mg/kg，定量限为0.03 mg/kg；在辣椒、番茄、香蕉、苹果和梨的空白果蔬样品中分别添加0.01、0.1和1 mg/kg 3 个水平下，回收率为93%~102%，相对标准偏差为4.2%~7.3%。该方法准确度和灵敏度高，抗干扰能力强，能准确并快速测定出水果、蔬菜中乙烯利的残留量。

Determination of ethephon residue in fruits and vegetables by gas chromatography after derivatization with (trimethylsilyl)diazomethane

An analytical method for the determination of ethephon residue in fruits and vegetables was established by using gas chromatography after derivatization with (trimethylsilyl)diazomethane. The samples were extracted with a mixture of hydrochloric acid and methanol (9:1, V/V). It was then extracted with anhydrous ether and subjected to derivatization by (trimethylsilyl)diazomethane. The extracts were determined by gas chromatography with the external standard method and qualitative by gas chromatography-mass spectrometry. The calibration curve of ethephon residue was linear in the range of 0.01-2 mg/L with correlation coefficients higher than 0.999 6. The detection limit of this method was 0.01 mg/kg and the limit of quantification was 0.03 mg/kg. In the samples of fruits and vegetables at spiked levels from 0.01 mg/kg to 1mg/kg, the recovery was 93%-102% with the relative standard deviation from 4.2%-7.3%. The method has the advantages of high accuracy, good sensitivity, and strong anti-interference ability, which can be used for the accurate and rapid determination of ethephon residues in fruits and vegetables.