DETERMINATION OF TIN IN CANNED FRUITS AND VEGETABLES BY ATOMIC-ABSORPTION SPECTROMETRY AND LIQUID-LIQUID-EXTRACTION

A method was developed for the determination of tin based on the extraction of its 5,5'-methylenedisalicylohydroxamic acid complex with 1.09M isobutyl methyl ketone in tributyl phosphate. After the samples were treated with nitric and hydrochloric acid, the aqueous phase was made to 0.05M in perchloric acid. When the ratio of aqueous phase to organic phase was 4:1 (v/v), the detection limit and the relative standard deviation (n = 7, 50 mu g tin) were 0.20 mu g/mL and 0.9%, respectively. The proposed method was applied to the analysis of tin in canned fruits and vegetables. The results were in good agreement with those obtained by the phenyl-fluorone method.