OBJECTIVETo establish the method of graphite furnace atomic absorption spectrometry for the measurement of stannum in urine with calcium nitrate as the matrix modifier.

METHODSGraphite tube was pretreated with calcium nitrate as the matrix modifier, the urine sample was diluted with 1% nitric acid and then direct injection was performed for these samples, and graphite furnace atomic absorption spectrometry was applied for measurement.

RESULTSThe concentration of stannum in urine showed a good linear relationship within the range of 8.0~40.0 μg/L, with a correlation coefficient of 0.9981. The minimum detectable concentration was 0.72 μg/L, the degree of precision was 1.54%~6.69%, and the recovery rate was 99.23%~107.63%.

CONCLUSIONThis method can determine the content of stannum in urine accurately and rapidly, with a high sensitivity and a low cost.