Determination of benzo(a)pyrene and aflatoxins (B1, B2, G1, G2) in vegetable oil by GPC-HPLC-FLD

摘要

This study develops a gel permeation chromatography-high performance liquid chromatography-fluorescence detection (GPC-HPLC-FLD) method for determination of benzo(a)pyrene and aflatoxins (B1, B2, G1, G2) in vegetable oil. In the method, sample is extracted with ethyl acetate/cyclohexane (1:1, v/v), and cleaned up with the GPC. The separation of target compounds is performed on a Extend C18 column (4.6 ?— 250 mm, 5 ??m) at 25 ?°C with methanol and 10 mmol La?’1 ammonium acetate solution as mobile phase with gradient elution at a flow rate of 1.0 mL mina?’1. The injection volume was 10 ??L, detection wavelengths were set at 360 nm (??ex) and 440 nm (??em) at 0a€“23 min, and 380 nm (??ex) and 408 nm (??em) at 23a€“35 min using FLD. The detection limits of benzo(a)pyrene and aflatoxins (B1, B2, G1, G2) were 0.5, 1.0, 1.0, 1.0 and 1.0 ??g kga?’1, respectively. The linear detection ranges of benzo(a)pyrene and aflatoxins (B1, B2, G1, G2) are 0.5a€“25.0 ??g kga?’1, 1.0a€“30.0 ??g kga?’1, 1.0a€“10.0 ??g kga?’1, 1.0a€“30.0 ??g kga?’1, 1.0a€“10.0 ??g kga?’1 with correlation coefficients (R2) of 0.9998, 0.9999, 0.9997, 0.9998, 0.9996, respectively. Recovery rates in vegetable oil spiked with target compounds are in the range of 82.6a€“101.6%, with the relative standard deviation of 4.85a€“9.84%. The real sample tests show that this simple and accurate method can be used for determination of benzo(a)pyrene and aflatoxins (B1, B2, G1, G2) in vegetable oil.