title: Method for the determination of total selenium in a wide variety of foods using inductively coupled plasma/mass spectrometry.
abstract: An optimized method for use in a high volume laboratory was developed and validated for the determination of total selenium in a wide variety of food products including infant formula. The method utilizes a single-stage, closed-vessel microwave digestion procedure with nitric acid. Upon completion of digestion, the solution is brought to volume with water. A dilution is prepared for analysis by adding methanol (MeOH) to an aliquot and then brought to volume by nitric acid diluent resulting in a 3% MeOH concentration. The amount of selenium is determined by inductively coupled plasma (ICP)/MS with the capability of removing argon-based polyatomic interferences. Experiments were conducted to validate the method by determining precision, accuracy, linearity, specificity, ruggedness, and robustness. The calculated practical reporting level for this method was 25.0 microg/kg. The method provided an average RSD of 2.03% during analysis of a wheat flour reference material and 2.73% during analysis of a powdered infant formula. The accuracy of the method for these materials was 98.6 and 105%, respectively. The method has also been used successfully on a variety of foods from various categories including fruits, grains, vegetables, protein, and dairy.
authors.affiliation: Covance Laboratories Inc., 3301 Kinsman Blvd, Madison, WI 53704, USA. Darryl.Sullivan@covance.com
authors.forename: Darryl
authors.initials: D
authors.lastname: Sullivan
authors.forename: Richard
authors.initials: R
authors.lastname: Zywicki
authors.forename: Mark
authors.initials: M
authors.lastname: Yancey
mesh_terms: D002138:Calibration; D005504:Food Analysis / Q000379:methods*; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D012643:Selenium / Q000032:analysis*; D013054:Spectrophotometry, Atomic / Q000379:methods*
chemical_list: D012643:Selenium