Determination of Ultratrace Copper in Barium Phosphate Laser Glass by Inductively Coupled Plasma Mass Spectrometry / 分析化学

ABSTRACT

With the use of high pure HF and HNO3 reagents, and autoclaves made of high purity Rerfluoroalkoxy ( PFA ) material, a solution sample digestion technique effective for phosphate samples, subjected to high temperature fusion, was established. The whole procedure was concise, fast and of low blank value. Key factors such as the amount and ratios of the reagents, the digestion temperature and time, were systematically optimized, it was found that within 0. 5 h at 150 ℃, only 1. 7 mL of total reagent consumption could lead to a complete sample decomposition. Most importantly, the samples were not required to be ground to fine powder, which greatly reduced the risk of contamination. In addition, an effective liquid_liquid extraction procedure based on 5_nonylsalicylaldehyde oxime as the extractant was established for matrix separation and analyte preconcentration. Under the optimal extraction conditions of 5 mL of 15% extractant, 0. 5% HNO3 of extraction acidity and 20% HNO3 of back_extraction acidity, a matrix separation efficiency of over 99. 999% could be realized and a preconctration factor of 10 could be obtained, which resulted in complete elimination of the matrix_induced interference and great enhancement of the analytical sensitivity. After optimization of the operation parameters of ICP_MS, high signal to background detection of Cu in 20%HNO3 at 840 W of plasma power and low sample uptake rate were realized. The detection limits of 2. 5 ng/g, RSD of 3. 3% for six detections of parallel samples, and the recovery of 94. 3% for spike test were obtained, respectively. The method was finally applied to three real samples analysis, and the results agreed well with the data from laser adsorption loss experiment.