Development of a new dispersive solid phase extraction based on nitrogen and sulfur doped new carbon sorbent for extraction and preconcentration of some mycotoxins in soybean milk samples and their determination by high performance liquid chromatography

Abstract

Introduction: Mycotoxins are natural compounds produced by fungies and can contaminate food products. Aflatoxins and ochratoxin A are the most important groups of mycotoxins. Objectives: The main goal of this study was the development of a solid phase extraction system combined with dispersive liquid–liquid microextraction based on new doped Nitrogen and Sulfur carbon sorbents for the extraction of mycotoxins from soymilk samples prior to their determination by HPLC-FLD. Method: A 10 mL of blank soymilk spiked with the studied mycotoxins at a concentration of 15 ng/L was placed into a test tube and then 0.2 g TCA was dissolved. After vortexing (for 2 min) and centrifugation (at 4000 rpm for 5 min), the supernatant phase was separated and transferred into another test tube. Then, 100 mg of the prepared sorbents were added into it and vortexed for 2 min. The supernatant phase was removed and the adsorbed analytes were eluted by 1.0 mL ACN. The obtained ACN was mixed with 75 µL chloroform and the mixture was quickly injected into 5 mL deionized water using a glass syringe. The chloroform droplets after centrifugation transferred for analysis by HPLC–FLD system. Results: Under optimal conditions, limits of detection and quantification in the first part were in the ranges of 0.13 to 0.83 and 0.43 to 2.7 and for the second part were in the ranges of 0.08 to 0.56 and 0.27 to 1.9 ng kg–1 , respectively. Discussion and conclusion: According to the results, this method can be used as an applicable method for extraction, preconcentration, and determination of mycotoxins in soymilk samples. Low LOD and LOQ, high EF and good repeatability are the important benefits of this study.