HPTLC-DPPH colorimetric-bioautographic image quantification of phenolic antioxidant: taking TBHQ in edible oil and baking foods as an example.

At present, the common detection methods of phenolic antioxidant TBHQ have the problems of cumbersome pretreatment, long time-consuming and can only determine one sample at a time. Therefore, it is urgent to establish a high-throughput, fast and accurate detection method. A rapid method for screening phenolic antioxidant TBHQ was established by combining high performance thin layer chromatography (HPTLC) separation with reduction discoloration reaction of 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and quantitative analysis of image pixels. On this basis, edible oil, bread and cake were taken as representative samples to verify the practical application performance of the proposed method. The results showed that the detection limit of the established method to detect TBHQ was 70 ng/zone (35mg/kg), the limit of quantification was 140 ng/zone (70mg/kg), and the limit of quantification was lower than the limit of use (200mg/kg) specified in GB 2760-2014. Through comparative analysis, the interference of the background matrix coexisting in the...