Homogenization of food samples for gamma spectrometry using tetramethylammonium hydroxide and enzymatic digestion

We have developed a method of food sample preparation for gamma spectrometry involving the use of tetramethylammonium hydroxide (TMAH) and/or enzymes such as alpha-amylase or cellulase for sample homogenization. We demonstrated the effectiveness of this method using food matrices spiked with Co-60, I-131, Cs-134,Cs-137, and Am-241 radionuclides, homogenized with TMAH (mixed salad, parmesan cheese, and ground beef); enzymes (alpha-amylase for bread, and cellulase for baked beans); or alpha-amylase followed by TMAH (cheeseburgers). Procedures were developed which are best compromises between the degree of homogenization, accuracy, speed, and minimizing laboratory equipment contamination. Based on calculated sample biases and z-scores, our results suggest that homogenization using TMAH and enzymes would be a useful method of sample preparation for gamma spectrometry samples during radiological emergencies.