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

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 Based on Organic Phase Anion Exchange SPE

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 selected as the mobile phase,TBHQ and BHA were separated completely within 3.4 min with Eclipse Plus C18 UPLC column in a gradient 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 operations,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.