【摘要】 建立胶束电动色谱在线推扫富集法检测蔬菜中残留的痕量甲基对硫磷。讨论了十二烷基硫酸钠(SDS)浓度、NaH2PO4浓度、缓冲液pH、有机溶剂添加量、样品中电解质浓度、运行电压、进样压力对富集效果的影响;考察了活性炭净化对回收率的影响。结果:选择20 mmol/L磷酸二氢钠+180 mmol/LSDS(pH=6.2),甲醇10%(体积分数)为缓冲液,电压7 kV,进样压力2 062.5KPa×s。1.8 g活性炭的加入对回收率没有明显的影响。甲基对硫磷在0.03 mg/L~2.5 mg/L范围内线性关系良好,相关系数为0.999 6,检测限为0.011 5 mg/L。加标水平在0.4 mg/kg~0.6 mg/kg范围内,回收率为90.44%~90.63%,RSD为1.12%~1.16%。胶束电动色谱在线推扫富集法可用于蔬菜中残留痕量农药的检测。更多还原

【Abstract】 A micellar electrokinetic chromatography(MEKC)Sweeping technique was developed for the determination of methyparathion in vegetables.The effects of the concentration of SDS, the concentration of NaH2PO4, the pH of running buffer,the concentration of organic additive,the concentration of solution to dilute sample,voltage and injection pressure on enrichment effect were discussed.The effect of additiving the activated carbon to sample on recovery was discussed.Results:20 mmol/L NaH2PO4+180 mmol/L SDS(pH=6.2),10 %methanol(V:V) was used as running buffer,the voltage was 7 kV,the injection pressure was 2 062.5 Kpa×s.The recovery was not effected by 1.8g activated carbon adding to the vegetable.The calibration curves had good linearity in the range of 0.03 mg/L-2.5 mg/L for folidol,the correlation coefficients was 0.999 6,the detection limit was 0.011 5 mg/L.At spiked levels of 0.4 mg/kg-0.6 mg/kg,the recoveries were 90.44 %-90.63 %,the relative standard deviations was 1.12 %-1.16 %.The MEKC method based on on-line Sweeping technique can be used to detect the residuals of trace pesticides in vegetables.更多还原