Abstract：The determination of acid-soluble aluminum in middle-low alloy steel by spark source atomic emission spectrometry was investigated. The effect of various sample preparation methods (milling machine and flat grinding machine) and argon state on determination results was discussed. It was found that the sample preparation by milling machine was the best selection, while sand paper may bring the interference of same-type elements if sample was prepared by flat grinding machine. After the sample was grinded with aluminum sand paper, the acid-soluble aluminum should be analyzed using overlapping-point excitation mode. The response curve of instrumental analysis program was modified. The acid-soluble aluminum was determined using the modified analysis program and overlapping-point excitation mode. The proposed method was applied to the analysis of low alloy steel standard sample. The relative standard deviations (RSD) were 1.2 % and 2.9 %, respectively. The found results of actual sample were consistent with those obtained by wet method. The analytical precision and comparison results between this method and wet analysis indicated that, the proposed method could fully meet the requirements of GB/T4336 (the residual aluminum nitride could be ignored).
