火焰原子吸收光谱法测定长石中的钾和钠

Determination of potassium and sodium in feldspar by flame atomic absorption spectrometry

建立火焰原子吸收光谱法测定长石中钾和钠的含量。样品采用硝酸–氢氟酸进行消解,用10 mL 5%的硝酸加热浸取后加水称量试液的质量,用火焰原子吸收分光光度仪进行测定。氧化钾和氧化钠的质量浓度在0.00～40.28μg/g范围内与吸光度呈良好的线性关系,相关系数为0.999 3～0.999 4,方法检出限为0.002 8～0.007 9μg/g。测定结果的相对标准偏差为0.78%～3.91%(n=6),测定值与标准值的相对误差为–1.70%～1.52%。该方法操作简单、快速,结果准确、可靠,满足地质样品的检测要求,适用于长石中钾和钠的测定。

A method for the determination of K and Na in feldspar by flame atomic absorption spectrometry was established. The samples were digested by nitric acid with hydrofluoric acid. After heating with 10 mL 5% nitric acid, water was added and the test solution was weighted, and then determination by flame atomic absorption spectrophotometer. The mass concentration of K2O, Na2O had good linear relationships with the absorbance in the range of 0.00–40.28 μg/g with the correlation coefficient of 0.999 3–0.999 4, and the detection limits were 0.002 8–0.007 9 μg/g. The relative standard deviation of the results was 0.78%–3.91%（n=6）. The relative error between the measured value and the standard value was –1.70%–1.52%. The method is simple, fast, accurate and reliable. It is suitable for the determination of K, Na and other metallic elements in feldspar.