Journal of Radioanalytical and Nuclear Chemistry

, Volume 314, Issue 2, pp 859–870 | Cite as

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

  • Kimi Nishikawa
  • Abdul Bari
  • Abdul Jabbar Khan
  • Xin Li
  • Traci Menia
  • Thomas M. Semkow
  • Zhichao Lin
  • Stephanie Healey


We have developed a method of food sample preparation for gamma spectrometry involving the use of tetramethylammonium hydroxide (TMAH) and/or enzymes such as α-amylase or cellulase for sample homogenization. We demonstrated the effectiveness of this method using food matrices spiked with 60Co, 131I, 134,137Cs, and 241Am radionuclides, homogenized with TMAH (mixed salad, parmesan cheese, and ground beef); enzymes (α-amylase for bread, and cellulase for baked beans); or α-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.


Gamma spectrometry Radiological emergency Food contamination Sample homogenization Tetramethylammonium hydroxide Volatilization of 131



K. Nishikawa acknowledges support by the U.S. Food and Drug Administration/Food Emergency Response Network’s Cooperative Agreement Continuation Program 5U18FD003485-08. We highly benefited from the discussions with C. Palmer (Wadsworth Center, New York State Department of Health) on the use of TMAH to homogenize protein samples. We are grateful to E. Fielman for discussion on sample aliquot factors.


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2017

Authors and Affiliations

  1. 1.Wadsworth Center, New York State Department of HealthAlbanyUSA
  2. 2.Department of Environmental Health Sciences, School of Public HealthUniversity at Albany, State University of New YorkRensselaerUSA
  3. 3.Winchester Engineering and Analytical Center, Food and Drug AdministrationWinchesterUSA

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