Author
MESTER, ZOLTAN - INMS, OTTAWA, CANADA | |
WILLIE, SCOTT - INMS, OTTAWA, CANADA | |
STURGEON, RALPH - INMS, OTTAWA, CANADA | |
CARUSO, JOSEPH - UN OF CINCINNATI, OHIO | |
FERNANDEZ, MARIA LUISA - UN OF OVIEDO, SPAIN | |
FODOR, PETER - UN OF BUDAPEST, HUNGARY | |
Goldschmidt, Robert | |
GOENAGA-INFANTE, HEIDI - LAB GOV CHEMIST, UK | |
LOBINDKI, RYSZARD - DEPT OF CHEM,POLAND | |
Wolf, Wayne |
Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/5/2005 Publication Date: 1/26/2006 Citation: Mester, Z., Willie, S., Sturgeon, R., Caruso, J.A., Fernandez, M., Fodor, P., Goldschmidt, R.J., Goenaga-Infante, H., Lobindki, R., Wolf, W.R. 2006. Certification of a new selenized yeast reference material (selm-1) for methionine, selenomethinone and total selenium content and its use in an intercomparison exercise for quantifying of these analytes. Analytical and Bioanalytical Chemistry. 385(1):168-180. Interpretive Summary: A new Selenized Yeast reference material (SELM-1) produced by Institute for National Measurement Standards, National Research Council of Canada (INMS, NRC) is certified for total selenium (2059 ± 64 mg/kg), methionine (Met, 5758 ± 277 mg/kg) and selenomethionine (SeMet, 3431 ± 157 mg/kg) content using GC-MS and LC-MS quantitation. Isotope dilution (ID) calibration using 13C-labelled SeMet and Met was used for both compounds. Total Se was determined by ID ICP-MS using a 82Se spike. An international intercomparison exercise involving seven laboratories (2 National Metrology Institutes (NMIs) and 5 university / government laboratories) was conducted by NRC to asses the state-of-the-art of measurement of selenomethionine and total Se in SELM-1. For SeMet, various acid digestion and enzymatic procedures followed by LC ICP-MS, LC AFS or GC-MS quantitation were used, and ten independent mean values were generated. Four values were based on species specific ID calibration, one on non-species specific ID with the remainder using standard addition (SA) or external calibration (EC). For total selenium, laboratories employed various acid digestion procedures followed by ICP-MS, AFS or GC-MS quantitation, with four laboratories employing ID calibration. The majority of participants submitted values within the certified range for selenomethionine and total Se. This information will be used by public and private sector food testing and analysis laboratories determining total Se and Selenomethionine in Dietary Supplements and foods. Technical Abstract: A new Selenized Yeast reference material (SELM-1) produced by Institute for National Measurement Standards, National Research Council of Canada (INMS, NRC) is certified for total selenium (2059 ± 64 mg/kg), methionine (Met, 5758 ± 277 mg/kg) and selenomethionine (SeMet, 3431 ± 157 mg/kg) content using GC-MS and LC-MS quantitation. Isotope dilution (ID) calibration using 13C-labelled SeMet and Met was used for both compounds. Total Se was determined by ID ICP-MS using a 82Se spike. An international intercomparison exercise involving seven laboratories (2 National Metrology Institutes (NMIs) and 5 university / government laboratories) was conducted by NRC to asses the state-of-the-art of measurement of selenomethionine and total Se in SELM-1. For SeMet, various acid digestion and enzymatic procedures followed by LC ICP-MS, LC AFS or GC-MS quantitation were used, and ten independent mean values were generated. Four values were based on species specific ID calibration, one on non-species specific ID with the remainder using standard addition (SA) or external calibration (EC). For total selenium, laboratories employed various acid digestion procedures followed by ICP-MS, AFS or GC-MS quantitation, with four laboratories employing ID calibration. The majority of participants submitted values within the certified range for selenomethionine and total Se. |