Poly (methacrylic acid-co-diethenyl-benzene) monolithic microextraction column and its application to simultaneous enrichment and analysis of mycotoxins.

A poly (methacrylic acid-co-divinyl-benzene) [poly (MAA-co-DVB)] monolithic column was specially prepared according to the chemical structures of the three mycotoxins of aflatoxin B1, zearalenone and sterigmatocystin, and used for in-tube solid-phase microextraction (in-tube SPME) of the selected mycotoxins. The poly (MAA-co-DVB) monolithic column was characterized in detail, and exhibited effective hydrophobic, π-π, and hydrogen bonding interactions towards the target analytes. By coupling the poly (MAA-co-DVB) monolithic column-based in-tube SPME with high-performance liquid chromatography, a simple, sensitive and matrix effect-free method for determination of mycotoxins was developed. Some important parameters related to extraction efficiency were optimized systematically. Under the optimal conditions, the enrichment factors for the three mycotoxins ranged from 71.9 to 98.7. Recoveries of mycotoxins in rice grains with three spiked concentration levels were in the range of 78.0-102.8%, with satisfactory relative standard deviations (n = 4) of 2.96-4.74%. Good linearity was obtained with correlation coefficients larger than 0.99, and the detection limits (S/N = 3) of the three mycotoxins were between 0.69 and 2.03μgkg-1. The developed poly (MAA-co-DVB) monolithic column based in-tube SPME-HPLC method was successfully used to sensitively determine trace mycotoxins in practical samples of rice grain without interference peaks, indicating that it is promising for the detection of trace mycotoxins in complex grain samples.