In-syringe dispersive micro-solid phase extraction method for the HPLC-fluorescence determination of aflatoxins in milk

The simultaneous determination of aflatoxins (B-1, B-2, M-1 and M-2) in milk using a new sample pretreatment technique, the in-syringe dispersive micro-solid phase extraction (ISD mu SPE), coupled with high performance liquid chromatography with fluorescence detection is described. The separation of the aflatoxins were performed using C18 Hypersil gold (250 mm x 4.6 mm, 5 mu m) column at 40 degrees C under gradient elution for 35 min. The excitation and emission wavelengths of the fluorescence detector were at 360 nm and 440 nm, respectively. Online photo-chemical derivatization was used to enhance the detection of aflatoxin B-1. Several parameters such as type and amount of sorbent, vortex speed, vortex time and elution solvent were evaluated. Limits of detection (LOD) ranged from 0.003 to 0.005 ng mL(-1), limits of quantification (LOQ) ranged from 0.01 to 0.02 ng mL(-1), recoveries ranged from 73.0 to 109.6%, and relative standard deviations (RSDs) was less than 17.3%. The proposed method was succesfully applied to the analysis of aflatoxins in milk.

Automated summary

A new sample pretreatment technique, ISD mu SPE, coupled with high performance liquid chromatography, was used for simultaneous determination of aflatoxins in milk. Online photo-chemical derivatization and optimization of parameters led to high sensitivity and accuracy in the analysis.