微波消解-电感耦合等离子体发射光谱法测定煤中磷

采用硝酸、硫酸、氢氟酸在高压密封微波消解体系中完全消解褐煤、烟煤和无烟煤样品,消解温度为180℃以上,以178.283 nm作为磷的分析谱线,电感耦合等离子体发射光谱法测定煤样中磷的含量。通过扣除背景的方法消除了基体干扰和光谱干扰,Si、Fe、Ca、Al、Mg对磷的检测无显著影响。磷浓度在0～10 mg/L范围内与等离子体发射强度呈良好的线性关系,方法检出限为0.09 mg/L,回收率为94.5%～101.2%,精密度(RSD,n=12)为1.89%～5.21%。方法用于分析标准物质,测定值与标准值一致。

Determination of Phosphorus in Coal Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry with Microwave Digestion

A method for the determination of phosphorus content in coal samples with Microwave Digestion was established by using inductively coupled plasma-atomic emission spectrometry(ICP-AES).The samples of lignitic coal,bituminous coal and anthracite coal were completely dissolved in HNO3-H2SO4-HF mixed acids at a temperature greater than 180℃ by high-pressure-airproof microwave digestion.The phosphorus was measured by ICP-AES using the 178.283 nm spectral line for analysis.The matrix interferences and spectral interferences were avoided by background correction.Si,Fe,Ca,Al and Mg have no outstanding effect on the measurement phosphorous.The linear range for phosphorus was 0-10 mg/L,and the detection limit was 0.09 mg/L.This method,when applied to the determination of phosphorus content in coal yields a relative standard deviation(RSD) of 1.89%-5.21% and recovery factors of 94.5%-101.2%.The results obtained using this method are in good agreement with the values of certified reference materials.