ICP-AES Determination of Iron, Calcium, Magnesium, Aluminum and Barium in Rich-Kalium Slate from Baiyunobo Mine

A method for the determination of Fe, Ca, Mg, Al and Ba in rich-kalium slate from Baiyunobo mine by inductively coupled plasma-atomic emission spectrometry (ICP-AES) was developed. Rich-kalium slate sample of 0.3 g was placed in a nickel and melted at 750 ℃ with sodium hydroxide of 2.0 g and sodium peroxide of 2.0 g, and then acidized by 20 mL hydrochloric acid. The contents of Fe, Ca, Mg, Al and Ba in the sample were determined by ICP-AES. Optimal analytical spectral lines of Fe, Ca, Mg, Al and Ba were 259.940, 396.847, 279.553, 396.152 and 493.408 nm. The results showed that linear relationships between values of mass concentration of Fe, Ca, Mg, Al, Ba and their emission intensity were kept in definite ranges, with detection limits (3s) of 0.016, 0.015, 0.002 4, 0.016, 0.014 mg·L^-1. The contents of Fe, Ca, Mg, Al, Ba in reference material of potassium feldspar (GBW 03116) and rich-kalium slate sample were determined by this method, giving RSDs (n=11) of the determined values in the range of 0.45%-7.0%. The determined values of reference material were consistent with its certified values. Recovery test was made by standard addition method, giving results in the range of 95.2%-100%.