瞬稳静态注射化学发光法测定农产品中甲胺磷残留量

目的建立测定农产品中甲胺磷残留量的新方法。方法本实验以鲁米诺-铁氰化钾体系对有机农药-甲胺磷进行化学发光分析,并找出最佳实验条件。测定农产品中甲胺磷残留量,并与高效液相色谱法比较,进行实际分析。结果静态注射化学发光法选用2.4×10-4mol/L的Luminol溶液,用量为2.00 mL,待测液的用量为2.00 mL。获得最理想发光曲线的仪器工作条件是-375V负高压、40 s发光时间。干扰实验表明保持甲胺磷浓度为0.05 mg/L,干扰允许值为±5%时,1 000倍的C1-、SO42-、NO3-、Ca2+,Mg2+、Fe3+等离子对测定没有干扰。2种方法测得样品的甲胺磷含量没有统计学意义。结论静态注射化学发光法简化了测试方法,缩短了时间。加标回收率为92.5%～104.3%,RSD<5%(n=5),为甲胺磷的检测提供实验依据。

Determination of methamidophos Residues in Agricultural Products by Instantaneous Steady Static Injection Chemiluminescence

Objective To establish a new method of detecting methamidophos residues in agricultural products.Methods In this experiment,methamidophos,one of organic pesticides,was detected and analyzed by using chemical luminescence with high sensitivity in luminol-potassium ferricyanide system,and found out the best experimental conditions.The result of determination of methamidophos residues in agricultural products,was compared with the result by high-performance liquid chromatography（HPLC） for practical analysis.Results In static injection chemiluminescence method,Luminol solution of 2.4×10^-4mol / L was selected with the dosage of 2.00 mL,and the dosage of testing liquid was also 2.00mL.The best working conditions of instrument that could obtain most idea luminescence curve was negative high voltage-375V,light-emitting time of 40s.And the Interfering test showed that when the permitting limit of interference at 0.05mg/L methamidophos was allowed values of ± 5 %,the ions such as Cl^-、SO4^2-、NO^3-、Ca^2＋,Mg^2＋ 、Fe^3＋ of 1 000 fold had no interference.The result of determination of methamidophos residues in samples by two kinds of methods had no significant differences.Conclusion The static injection chemiluminescence method simplified the testing method and shortened the determination time.The recoveries of standard addition of 92.5 %～104.3 % and R5 %（n=5）.The new method should provide experimental basis for the detection of methamidophos.