玉米蛋白粉中高毒有机磷农药残留测定及基质效应研究

建立同时测定玉米蛋白粉中高毒有机磷农药甲胺磷、甲拌磷、毒死蜱、甲基嘧啶磷残留量的气相色谱分析方法。样品经乙酸乙酯提取，用中性氧化铝和活性炭作为净化剂，采用DB-1型毛细管色谱柱及FPD检测器检测，并对检测中的基质效应现象进行研究。利用阴性样品空白基质配置标准曲线进行定量分析时，发现不同农药在玉米蛋白粉中的基质效应程度不同，其中个别农药在基质中受到保护。本方法避免了保留时间漂移、检测结果假阳性和峰型拖尾的问题，结果表明，测定4种有机磷农药残留量的线性范围均为0．1-0．5mg／L，相关系数为O．9974-0，9989，检出限为0．001-0．009mg／L，3个水平的加标回收率为80．20％．92．40％，相对标准偏差为0．70％．5．47％。

Determination of Organ-Phosphorus Pesticide Residues in Corn Protein Powder by Gas Chromatography and Its Effect on Matrix

A method to determine multi-residue of methamidophos, phoyate, chlorpyrltos and parathlon-metlayl m corn protein powder by gas chromatography was discussed in this paper. The residues of organ-phosphorous pesticides in corn protein powder were extracted by ethyl acetate, and the extracts, cleaned up using neutral aluminae and activated carbon. Four types of the target were separated on the DB-1 capillary column and detected by FPD detector. Using negative blank sample matrix configuration standard curve, matrix effect degree of pesticides for corn protein powder was different. Few pesticides were protected in the matrix, and the drift of retention time, false positive results and the peak tailing, avoided. The internal method of matrix-matched calibration standard was used for quantification. Satisfactory results were obtained. The linearity was good in the range of 0.1 and 0.5 mg/L with the regression coefficient from 0.9974 to 0.9989. Detection limit ranged from 0.001mg/L to 0.009mg/L, average recoveries of the organ-phosphorous pesticides spiked at 0.1, 0.3 and 0.5 mg/kg were between 80.20 and 92.40% with relative standard deviations of less than 0.70%.