Thursday, November 8, 2007 - 9:05 AM
Pavilion VII (Intercontinental at the Plaza)
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HPLC Determination of Melamine, Ammeline, Ammelide, and Cyanuric Acid Contamination in Wheat Gluten and Rice Protein Concentrate

Robert Smith, Jimmie Weigand, and Joan Nandrea. US FDA Laboratory, Lenexa, KS

Wheat gluten or rice protein concentrate was extracted with pH 2.5, 50 mM phosphate buffer by stirring vigorously for four hours at 60C. The extract was injected onto a combination of two columns in series (a short strong cation exchange column and a C18 column) and eluted using a 50 mM phosphate pH 2.5 buffer. The limit of detection (LOD) and limit of quantification (LOQ) were estimated from the noise level to be approximately 100 g/mL and 400g/mL respectively for melamine, ammeline, and cyanuric acid in the original material. Ammelide LOD and LOQ were estimated at 10g/mL and 40g/mL respectively. Spike recoveries were 98% to110%. This method is useful for quantitation in the range of 0.1% to 5% for melamine and cyanuric acid, and from 400 ppm to 10,000 ppm for ammeline and from 50 ppm to 10,000 ppm for ammelide in the wheat gluten or rice protein.