ICP-AES Determination of 12 Heavy Metal Elements Migrated from Stainless Steel Food Container

The cleaned stainless steel food container was filled with HOAc (4+96) to a definite volume and boiled for 30 min. After cooling HOAc (4+96) was added to the original volume to replace loss by evaporation and the food container was soaked with the HOAc (4+96) for 24 h. The solution obtained was used for ICP-AES determination of the 12 elements migrated from the stainless steel container. Based on the results of test for interferences of co-existing elements, 12 spectral lines with relatively higher intensity and less interference were chosen as the analytical lines. Three working parameters for the instrument were optimized and given as follows: ① RF power: 1 250 W; ② flow-rate of carrier gas: 0.6 L·min-1; and ③ height of observation: 16 mm. Linear relationships between values of spectral intensity and mass concentration of the 12 elements were found in the same range of 0.05 to 1.0 mg·L-1, with detection limits (3s) range from 0.001 to 0.013 mg·L-1. Values of recovery found by standard addition method were in the range of 98.2% to 104%. Values of RSD′s (n=10) found by replicate determination of the 12 elements in a same sample solution were all less than 3.0%.