固相萃取-高效液相色谱法测定芦柑2,4-D残留

建立永春芦柑（Citrus Reticulata Banco）2,4-二氯苯氧乙酸（2,4-D）残留量高效液相色谱（HPLC）测定方法。样品用乙酸乙酯超声波提取,对比C18、硅胶、硅藻土三种固相萃取柱净化效果,洗脱液2,4-D富集10倍后HPLC检测。HPLC条件：C18色谱柱;波长230nm;流动相为60%甲醇-pH2.5磷酸水溶液。2,4-D的线性范围1.00~20.00mg·kg-1,线性相关系数0.9998。合理用药时芦柑果皮2,4-D残留量0.74 mg·kg-1,芦柑2,4-D含量0~0.75 mg·kg-1,变异系数1.4%~5.5%,2,4-D回收率86%~92%。

Solid Phase Extraction Coupled with HPLC for the Determination of 2,4-D Residues in Citrus

In this work, a HPLC method for the determination of 2,4-D residues in Citrus was established. The sample was extracted with ethyl acetate in an ultrasonic bath, then preconcentrated by solid-phase extraction with C18, Silica, Florisil cartrages, respectively, and the extraction were enriched with a value of 10. The separation was performed on a C18 column by a mobile phase consisting of 60% methanol and phosphoric acid solution （pH2.5）. Detection was carried out by an ultraviolet detector at 230 nm. Under the optimized conditions, the linear range was 1.00-20.00mg · kg-1 with a correlation coefficient of 0. 9998. The 2, 4-D residues in citrus were 0.74 mg ·kg-1 when 2.4-D was in correct use. The 2,4-D residues in five batches detected were between 0 to 0.75 , mg· kg-1. The relative standard deviation in results was 1.4% -5. 5%, with the recoveries ranging from 86% to 92%.