Extraction aflatoxins from cereals using agerogel @ COF composite and evaluating ultraviolet and microwave irradiation and sonication effect on their decontamination

TL;DR

A new method using a composite material was developed to extract and measure aflatoxins in cereals, with effective decontamination techniques tested.

Contribution

A novel aerogel@covalent organic framework composite was synthesized and applied for the extraction of aflatoxins from cereals.

Findings

The composite material effectively extracted aflatoxins B1, B2, G1, and G2 from cereal samples with high linearity.

Detection and quantitation limits were very low, indicating high sensitivity of the method.

Microwave, ultraviolet, and sonication methods were evaluated for aflatoxin decontamination with promising results.

Abstract

A dispersive solid-phase extraction method was proposed for the extraction of aflatoxins (B1, B2, G1, and G2) from cereal samples. A covalent-organic framework and graphene aerogel composite were evaluated for their capacity to extract and preconcentrate aflatoxins in the microextraction method. In the proposed method, aflatoxins were extracted with deionized water and acetonitrile (9:1, v/v), aflatoxins were adsorbed to a small amount (10 mg) of the sorbent, desorbed with a low volume of acetonitrile, and determined by high performance liquid chromatography-fluorescence detection. The extraction conditions including the type and amount of adsorbent, stirring conditions, concentration of NaCl, pH, and the type and volume of elution solvent optimized using a “one-variable-at-a-time” strategy. Under these optimized conditions, aflatoxins were effectively extracted from the cereal samples. Good linearity was obtained with correlation coefficients (r2) of 0.999, 0.996, 0.999, and 0.987 for aflatoxins B1, B2, G1, and G2, respectively. The detection limits for aflatoxins B1, B2, G1, and G2 were 0.014, 0.009, 0.021, and 0.012 μg/kg, respectively and the quantitation limits were 0.047, 0.032, 0.064, and 0.04 μg/kg respectively. The extraction recoveries of the analytes ranged from 41.7 to 52.6% using the developed method. The relative standard deviations for intra (n = 6) and inter-day (n = 6) precisions for aflatoxins at two concentration levels (2 and 5 μg/kg) were ≤ 8.3% and ≤ 10.2%, respectively. These results indicate that the suggested extraction protocol combined with the detection system can be applied for the sensitive analysis of trace amounts of aflatoxins in food samples.

•A new aerogel@covalent organic framework was synthesized, characterized and used in extraction procedure.•DSPE of four aflatoxins were done from cereal samples•Microwave, ultraviolet, and ultrasound-assisted degradation of aflatoxins were evaluated.•Accurate, reliable, sensitive, and effective results were obtained by the method.

A new aerogel@covalent organic framework was synthesized, characterized and used in extraction procedure.

DSPE of four aflatoxins were done from cereal samples

Microwave, ultraviolet, and ultrasound-assisted degradation of aflatoxins were evaluated.

Accurate, reliable, sensitive, and effective results were obtained by the method.

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