Atomic absorption spectrometric determination of tin in canned foods using nitric acid-hydrochloric acid digestion and nitrous oxide-acetylene flame.

Foods (5-40 g) are digested sequentially with HNO3 and HCI, diluted to 100 mL, and filtered, and tin is determined by atomic absorption using an N2O-C2H2 flame. Synthetic standards in 10% HCl are used. A positive interference by potassium is compensated by adding 100 micrograms potassium/mL to both standards and samples. Recoveries for 17 foods spiked with tin at levels between 40 and 500 micrograms/g ranged from 85 to 110% with a mean of 101%. Results agreed well with a solvent extraction atomic absorption method and a direct X-ray fluorescence method.