Detection of moniliformin in maize using capillary zone electrophoresis

Abstract

Moniliformin is a mycotoxin produced by certain fungi pathogenic to maize. It is capable of causing disease in domestic animals, possibly through inhibition of pyruvate dehydrogenase. Testing for MON commonly involves extraction of maize, isolation of moniliformin using solid-phase extraction columns and detection with high-performance liquid chromatography (HPLC) or gas chromatography. A capillary zone electrophoresis-diode array detection (CZE-DAD) method for determination of moniliformin in maize is reported. The extraction and isolation procedures are similar to those of a commonly used HPLC method, while the detection step requires only 10 min. Sixty-three samples of maize were tested by an established HPLC method using absorbance at 229 nm (HPLC-ultraviolet light) and by the CZE-DAD method. The limit of detection of the CZE-DAD method was 0.1 μg MON g⁻¹ maize compared with 0.05 μg g⁻¹ for the HPLC-ultraviolet light method. The CZE-DAD method gave good agreement with the HPLC-ultraviolet light method for samples tested at levels up to 1500 μg g⁻¹, with a linear regression of r ² = 0.996.

Keywords:

• moniliformin
• mycotoxin
• capillary electrophoresis
• detection

Acknowledgement

The author thanks Mr John Bobell, USDA-ARS-NCAUR, for exceptional technical assistance, Mr Ronald D. Plattner, USDA-ARS-NCAUR, for graciously providing moniliformin, Dr Anne Desjardins, USDA-ARS-NCAUR, for producing and providing the field inoculated maize, and Ms Stephanie Folmar, USDA-ARS-NCAUR, for shelling the inoculated maize. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the products, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable.