The trace lithium content of different kinds of samples was determined by flame photometry using the atomic absorption spectrophotometer with air-acetylene flame at the optimum instrumental conditions, after the decomposition of a sample with nitricperchloric acid mixture or the decomposition of a freeze-drying food sample with nitric-perchloric-hydrofluoric acid mixture. In the highpurity chemicals lithium content as impurity was considerably higher in calcium salt (metal: 39500ng/g, oxide: 21500ng/g, carbonate: 13700〜14400ng/g) than in magnesium (11〜67ng/g), sodium (198〜634ng/g) and potassium salt (196〜361ng/g). In the carbonate minerals the content was higher in aragonite (av. 21970ng/g) and calcite (av. 14100ng/g) than in dolomite (av. 9959ng/g) depending on calcium content as a matrix component. In the table-salt samples of sea-, lake- and rock-salt the content was 934, 724 and 870ng/g, respectively, and the lithium content was summarized to be 900ng/g as mean for all the 34 samples. In the rice the content was three times higher than in unpolished rice av. 12.7ng/g than in polished rice av. 5.2ng/g. Finally in the cow\u27s milk the content was almost constant to be av. 23.7ng/g regardless with the different fat-content, pasteurized temperature and manufactured district (Prefecture in Japan). In addition to an annual variation of the lithium content of a same brand of cow\u27s milk the content was also almost constant to be av. 24.3ng/g, regardless of four seasons.The trace lithium content of different kinds of samples was determined by flame photometry using the atomic absorption spectrophotometer with air-acetylene flame at the optimum instrumental conditions, after the decomposition of a sample with nitricperchloric acid mixture or the decomposition of a freeze-drying food sample with nitric-perchloric-hydrofluoric acid mixture. In the highpurity chemicals lithium content as impurity was considerably higher in calcium salt (metal: 39500ng/g, oxide: 21500ng/g, carbonate: 13700〜14400ng/g) than in magnesium (11〜67ng/g), sodium (198〜634ng/g) and potassium salt (196〜361ng/g). In the carbonate minerals the content was higher in aragonite (av. 21970ng/g) and calcite (av. 14100ng/g) than in dolomite (av. 9959ng/g) depending on calcium content as a matrix component. In the table-salt samples of sea-, lake- and rock-salt the content was 934, 724 and 870ng/g, respectively, and the lithium content was summarized to be 900ng/g as mean for all the 34 samples. In the rice the content was three times higher than in unpolished rice av. 12.7ng/g than in polished rice av. 5.2ng/g. Finally in the cow\u27s milk the content was almost constant to be av. 23.7ng/g regardless with the different fat-content, pasteurized temperature and manufactured district (Prefecture in Japan). In addition to an annual variation of the lithium content of a same brand of cow\u27s milk the content was also almost constant to be av. 24.3ng/g, regardless of four seasons
