金属有机骨架基质固相分散高效液相色谱法检测食用油中苯并[a]芘

目的建立基于金属有机骨架材料(metal-organic frameworks, MOFs) MIL-101(Cr)的基质固相分散进行食用油样品前处理,并以高效液相色谱串联荧光检测器(high performance liquid chromatography-fluorescence detector, HPLC-FLD)对苯并a]芘进行定量检测。方法吸附后将体系装填于6 mL固相萃取空柱,以丙酮洗脱,氮气吹干定容。色谱流动相为乙腈-水(80:20, V:V),流速0.3 mL/min,激发波长369 nm,发射波长404 nm,外标法定量。结果苯并a]芘在1～50ng/g范围内呈良好线性,相关系数r~2为0.9997,加标回收率为96.0%～99.9%。方法检测限及定量限分别为0.33ng/g和1.09ng/g,实际样品检测的相对标准偏差为2.8%～8.9%。结论该方法操作简单,测定结果准确,同时克服了常规固相萃取法易堵塞、渗漏、过载及负压过高等问题,可用于食用油中苯并a]芘的检测。

Determination of benzo(a)pyrene in edible oil by matrix solid-phase dispersion based on metal-organic frameworks combined with high performance liquid chromatography

Objective To establish the matrix solid-phase dispersion method based on metal organic frameworks (MOFs) MIL-101 (Cr) for the pre-treatment of edible oil and determinate the benzo(a)pyrene by high performance liquid chromatography coupled with fluorescence detector (HPLC-FLD). Methods After adsorption, the system was filled in a 6 mL empty SPE column, eluted with acetone and dried with nitrogen at a constant volume. The chromatographic mobile phase was acetonitrile-water (80:20, V:V), the flow rate was 0.3 mL/min, the excitation wavelength was 369 nm, the emission wavelength was 404 nm and external standard method was used to quantitative determination. Results In the range of 1-50 ng/g, the coefficient of determination (r2) was 0.9997, and the recoveries were 96.0%-99.9%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.33 ng/g and 1.09 ng/g, respectively. The relative standard deviations (RSDs) of the actual samples were 2.8%-8.9%. Conclusions This method is simple in operation and accurate in determination, it overcomes the problems of easy clogging, leakage, overload and high negative pressure of the solid phase extraction, which is accurate and stable for application to various edible oil samples.