基质相容性溶胶-凝胶固相微萃取涂层直接萃取柑橘中农药残留

Matrix-compatible sol-gel coating for direct immersion solid-phase microextraction of pesticides residues in citrus

为了开发新的可利用的基质相容性固相微萃取(solid phase microextraction,SPME)涂层,促进活体SPME采样技术的发展。本研究评价了溶胶-凝胶聚二甲基硅氧烷萃取头在柑橘基质中的基质相容性,建立了直接SPME-气相色谱法检测柑橘果浆中有机磷农药的方法。结果表明:在柑橘果肉匀浆并添加同样质量的水,调节pH至1.84、50℃萃取60min、搅拌速度为1200r/min条件下,5种有机磷农药在线性范围内具有良好的线性关系,R2≥0.999,检测限为0.002~0.046μg/kg,加标回收率为71.0%~125.3%,相对标准偏差为0.5%~15.6%。该萃取头在柑橘活体基质中可以连续使用50次以上。

In order to develop new available matrix-compatible solid phase microextraction (SPME) coating and promote the development of in vivo SPME sampling technology in agriculture,the matrix compatibility of sol-gel polydimethylsiloxane coating was evaluated and a simple and sensitive DI-SPME/gas chromatography method was established for analysis of five organophosphorus pesticides in citrus pulp.When the citrus pulp was diluted by equal amount of water,adjusted to pH 1.84,and subjected to DI-SPME at 50 ℃ for 60 min with a stirring rate of 1 200 r/min,the good linear ranges were obtained with linear regression coefficients ( R 2 ) greater than 0.999 for all test compounds in citrus matrix as well as low limits of detection (ranging from 0.002 to 0.046 μg/kg),good repeatability (0.5%-15.6%) and high recoveries (71.0%-125.3%).The sol-gel fiber could be used more than 50 times for in vivo sampling in citrus pulp.