Determination of Major and Minor Components in Dolomite by X-Ray Fluorescence Spectrometry after Fusion Sample Preparation

A method for the simultaneous determination of calcium oxide, magnesium oxide, silicon dioxide, aluminum oxide, iron oxide, titanium dioxide, potassium oxide, sodium oxide and phosphorus pentaoxide in dolomite by X-ray fluorescence spectrometry after fusion sample preparation was established. 6.000 0 g of the flux mixture (lithium tetraborate and lithium metaborate with mass ratio of 67:33) was weighed, half of the flux was poured into a Pt-Au crucible, and ammonium iodide (0.2 g) and the dried sample (0.900 0 g) were added subsequently. After mixing well, the remaining flux was taken and covered on the surface of the above mixture for melting at 1 000 ℃ for 12 min, the glassy slice of sample obtained was analyzed by XRFS. The series of standard samples for calibration were prepared by melting of the mixtures of standard materials, spectral pure reagents and reference reagents, matrix effect and spectral line overlapping effect were corrected by empirical α coefficient method. The results showed that linear correlation coefficients of calibration curves were found beween 0.993 8 and 1.000, with detection limits ranged from 9.31 μg·g^-1 to 129.1 μg·g^-1. The actual samples were analyzed by eleven repeated determinations in a single-day and 11 days repeated determinations, RSDs of the determined values was not greater than 6.0% or 10%; single-day and 11 days (1 sample per-day) continuous determinations were made on 11 parallel-prepared samples, RSDs of the determined values was not greater than 7.0% or 8.0%. The proposed method was applied to analyze standard substances and actual samples, errors between the determined values and the certified values or the determined values obtained from GB/T 3286-2012 were all within the allowable error range of GB/T 3286-2012.