改进固相萃取-高效液相色谱法测定食用油中苯并(a)芘

Detemination of benzo( a) pyrene level in cooking oil by improved solid phase extraction-high performance liquid chromatography

目的 建立改进固相萃取-高效液相色谱-荧光检测器检测食用油中苯并（a）芘的方法。方法 以中性氧化铝作为食用油固相萃取前处理净化填料。样品经中性氧化铝固相萃取柱前处理净化后采用UltimateXB-C18色谱柱（250 mm×4.6 mm,5μm）,以乙腈-水（88∶12,V/V）为流动相,流速为1.0 ml/min,柱温为30℃,进样量为10μl,在激发波长384 nm、发射波长406 nm处进行检测。试验过程中重点考察了不同含水量的中性氧化铝对油脂的去除效果和苯并（a）芘的回收率效果,最终筛选出含水量为6%的中性氧化铝作为检测食用油中苯并（a）芘的专用前处理净化填料。结果 本方法的检出限为0.5 ng/g,线性范围0.5~100 ng/ml,加标回收率在91.2%~101.0%之间,相对标准偏差在2.2%~2.9%之间。结论 该方法灵敏度高,选择性好,定量准确,适用于食用油中苯并（a）芘的准确检测。

Objective To establish an improved solid phase extraction-high performance liquid chromatography method with fluorescence determination for the detection of benzo（a） pyrene （ B（a） P） in cooking oil. Methods Cooking oil samples were prepared by neutral alumina solid phase extraction （SPE） column. This study investigated the effect of grease removal and recovery of B（a） P as a function of water content in the neutral alumina packing. Neutral alumina packing with 6% water content was found to be the best solid phase extraction packing for B（a） P pre-treatment. In the HPLC method, the HPLC column used was Ultimate XB-CIs （250 mm × 4.6 mm, 5 μm） column from Welch Materials, Inc. The mobile phase was acetonitrile-water （88： 12, V/V） with a flow rate of 1.0 ml/min, the column temperature was 30 ℃ , and the injection volume was 10 μl. Results The limit of determination was 0.5 ng/g （ S/N = 3） , the linear range was 0.5- 100 ng/ml, the recoveries were 91.2% -101.0% and the relative standard deviations were 2.2% -2.9%. Conclusion The method is highly sensitive with good selectivity and accurate quantification, which is suitable for B（a） P determination in cooking oil.