火焰原子吸收光谱法测定天然气转化催化剂中的氧化钾

建立火焰原子吸收光谱法测定天然气转化催化剂中氧化钾的分析方法。该方法将催化剂样品和助溶剂四硼酸锂熔融后再用盐酸溶解定容,采用火焰原子吸收光谱仪对样品溶液进行测定。在优化的实验条件下,钾离子的质量浓度在0.05~0.50 mg/L范围内与吸光度呈良好线性关系,相关系数为0.9995。钾的方法检出限为0.001 mg/L,定量限为0.01 mg/L,测定结果的相对标准偏差为2.6%~4.3%(n=6),样品加标回收率为97.8%~102.3%。与HG/T 3543-2014中的酸溶制样法相比,该方法能够将催化剂样品中的难溶钾盐溶出,分析结果准确度更高,可用于天然气转化催化剂中氧化钾含量的测定。

Determination of potassium oxide in natural gas conversion catalyst by flame atomic absorption spectrometry

A method for the determination of potassium oxide in natural gas conversion catalyst by flame atomic absorption spectrometry was established.The catalyst sample were fused with lithium tetraborateand,which was determined by flame atomic absorption spectrometer.Under optimized experimental conditions,the concentration of K+had a good linear relationship with absorption in the range of 0.05-0.50 mg/L.The correlation coefficient was 0.9995.The detection limit of K+was 0.001 mg/L and the quantitative limit was 0.01 mg/L.The relative standard deviation of the detection results was 2.6%-4.3%(n=6),and the recovery of standard addition was 97.8%-102.3%.Compared with acid solution method in HG/T 3543-2014,the new sample preparation method may dissolve insoluble potassium salt from catalyst samples,and gave more accurate result.This method can be used to analyze the content of potassium oxide in natural gas conversion catalyst.