分散固相萃取-高效液相色谱法快速测定果蔬中的6种保鲜剂残留量

Rapid determination of six preservative residues in fruits and vegetables by high performance liquid chromatography using dispersive solid phase extraction

建立了采用分散固相萃取-高效液相色谱同时测定果蔬中2,4-滴、噻苯咪唑、乙萘酚、邻苯基苯酚、二苯醚和联苯6种保鲜剂残留量的方法。样品经乙腈提取(同时加入氯化钠和无水硫酸镁),提取液经酸性氧化铝分散固相萃取净化,采用Agilent TC C18色谱柱(250 mm×4.6 mm,5μm),以甲醇-0.02 mol/L的磷酸二氢钾溶液(pH 6)作为流动相,流速1.0 mL/min,梯度洗脱,用紫外检测器检测,检测波长为235 nm,外标法峰面积定量。6种保鲜剂在0.5～20 mg/L范围内线性关系良好,相关系数均大于0.99;6种保鲜剂在样品中添加1、2和10 mg/kg 3个浓度水平的回收率为84.2%～99.1%(n=6),相对标准偏差为1.67%～10.3%;方法的定量限为1 mg/kg。该法简便、准确,适用于果蔬中6种保鲜剂残留量的检测。

A dispersive solid phase extraction-high performance liquid chromatographic （HPLC） method was established for the simultaneous determination of 2,4-D, thiabendazole, 2-naphthol, o-phenyl phenol, diphenyl ether and biphenyl in the fruits and vegetables. The samples were vortexed for extraction with acetonitrile containing sodium chloride and anhydrous magnesium sulfate. The acetonitrile extraction was purified by acidic alumina dispersed solid phase extraction. The analysis was performed on an Agilent TC C18 column （250 mm x 4.6 nun, 5 μm） and an ultraviolet detector at 235 nm with a mobile phase of methanol-0.02 mol/L （ pH 6） potassium dihydrogen phosphate solution, at a flow rate of 1.0 mL/min with gradient elution. Good linearities were observed in the range of 0. 5 - 20 mg/L with correlation coefficients greater than 0.99. The average recoveries of the six preservatives in fruits and vegetables were in the range of 84.2% -99. 1% at three spiked levels of 1, 2 and l0 mg/kg （ n =6） and the relative standard deviations （RSDs） were in the range of 1.57% - 10.3%. The limits of quantifi- cation were I mg/kg. This method is simple, accurate and suitable for the determination of the six preservatives in fruits and vegetables.