Arsenic has been measured in food and food supplement Standard Reference Materials by neutron activation analysis for the purpose of value-assigning As mass fractions and assessing homogeneity. Instrumental neutron activation analysis (INAA) has been used to value assign As in candidate food supplement SRMs 3532 Calcium Supplement, and 3262 St. Johns Wort Aerial Part down to about 100 µg/kg as well as two additional candidate St. Johns Wort SRMs with As mass fractions < 100 µg/kg. In the latter case, the presence of significant 24Na and 82Br limited the reproducibility of the method below 100 µg/kg. For measurement of lower As mass fractions, a radiochemical neutron activation analysis (RNAA) with extraction of As3+ into dimethyldithiocarbamate in chloroform has been developed with detection limits down to 0.1 µg/kg As. The procedure has been used to value-assign As mass fractions for SRM 3280 Multivitamin Tablets and for candidate food SRMs Fortified Breakfast Cereal, and at < 10 µg/kg in 1845a Whole Egg Powder.
Citation: Journal of Radioanalytical and Nuclear Chemistry
Pub Type: Journals
activation analysis, neutrons, arsenic, radiochemistry, foods, food supplements, analytical chemistry