Determination of aflatoxins in cereal flours by solid-phase microextraction coupled with liquid chromatography and post-column photochemical derivatization-fluorescence detection

• Published in: Journal of Chromatography A 2009-12, Vol.1216 (49), p.8636-8641
• Main Authors: Quinto, M., Spadaccino, G., Palermo, C., Centonze, D.
• Format: Article
• Language: English
• Subjects: Aflatoxins; Analytical chemistry; Biological and medical sciences; Cereal and baking product industries; Cereals; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Extraction; Flour; fluorescence; Fluorescence detection; food contamination; Food industries; Fundamental and applied biological sciences. Psychology; High performance liquid chromatography; HPLC; Liquid chromatography; Microbiology; microextraction; Mycology; Other chromatographic methods; Pathogenicity, host-agent relations, miscellaneous strains, epidemiology; Photochemical; Photochemical derivatization; photochemical derivitization; solid phase extraction; solid phase microextraction; SPME
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2009.10.031

A new method for the determination of aflatoxins B 1, B 2, G 1, and G 2 (AFB 1, AFB 2, AFG 1, AFG 2) in cereal flours based on solid-phase microextraction (SPME) coupled with high performance liquid chromatography with post-column photochemical derivatization and fluorescence detection (SPME–HPLC–PD–FD) has been developed. Aflatoxins were extracted from cereal flour samples by a methanol:phosphate buffer (pH 5.8, I = 0.1) (80:20, v/v) solution, followed by a SPME step. Different SPME and HPLC–PD–FD parameters (fiber polarity, temperature, pH, ionic strength, adsorption and desorption time, mobile phase) have been investigated and optimized. This method, which was assessed for the analysis of different cereal flours, showed interesting results in terms of LOD (from 0.035 to 0.2 ng g −1), LOQ (from 0.1 to 0.63 ng g −1, respectively), within and inter-day repeatability (2.27% and 5.38%, respectively) linear ranges (up to 20 ng g −1 for AFB 1 and AFG 1 and 6 ng g −1 for AFB 2 and AFG 2), and total raw extraction efficiency (in the range 55–59% at concentrations in the range 0.3–1 ng g −1 and 49–52% at concentrations in the range 1–10 ng g −1). The results were also compared with the purification step carried out by conventional immunoaffinity columns.