有机相阴离子交换SPE-UPLC-UV法快速测定食用植物油中的抗氧化剂TBHQ和BHA

A Rapid UPLC-UV Method for Simultaneous Determination of Antioxidants TBHQ and BHA in Edible Vegetable Oils Based on Organic Phase Anion Exchange SPE

建立了基于有机相阴离子交换SPE前处理的UPLC-UV法,快速测定食用植物油中的抗氧化剂TBHQ和BHA。食用植物油样品用正己烷稀释后,直接上样至Oasis MAX聚合物材质阴离子交换SPE柱中进行净化,用正庚烷淋洗去除甘油酯成分,用0.5%甲酸-四氢呋喃溶液洗脱。以纯水和甲醇为流动相,TBHQ和BHA在Eclipse Plus C18上和梯度洗脱条件下3.4 min内达到基线分离;检测波长为290 nm;进样量为1μL。TBHQ和BHA在5~200 mg/L范围内线性关系良好(r≥0.999 95);在10、50、200 mg/kg这3个水平的加标回收率为91.5%~104%,相对标准偏差为1.2%~4.4%。方法定量限为0.5 mg/kg。与已有方法相比,该方法样品前处理更简便快速、色谱分离时间短、结果准确,可广泛用于食用植物油样品中TBHQ和BHA等抗氧化剂的快速检测。

A rapid UPLC-UV method for simultaneous determination of antioxidants TBHQ and BHA in edible vegetable oils was developed based on organic phase anion exchange SPE. Vegetable oils were directly diluted with n-hexane,and then loaded into Oasis MAX cartridges for purification, n-Heptane was adopted to remove glycerides residues in the cartridge bed. TBHQ and BHA were eluted into a glass tube with 0. 5% formic acid tetrahydrofuran solution. The eluted sample solution was mixed thoroughly, and then filtered into the sampling bottles with a PFTE syringe filter for UPLC analysis. The pure water and methanol were select- ed as the mobile phase,TBHQ and BHA were separated completely within 3.4 min with Eclipse Plus C18 UPLC column in a gra- dient elution mode. The wavelength of detector was set at 290 nm. The injection volume was 1 μL. The linearity of the method was good with r≥ 0. 999 95 over the concentration range from 5 to 200 mg/L. The recoveries for TBHQ and BHA were between 91.5% and 104% with the relative standard deviation between 1.2% and 4.4% at 10,50 or 200 mg/kg levels. The limits of quantification were 0. 5 mg/kg for both TBHQ and BHA. The method shows the more rapid and easier sample pretreatment opera- tions, much shorter chromatographic separation time, good recoveries and accuracies. The method can be widely applied in rapid analysis of antioxidants like TBHQ and BHA in edible vegetable oils.