石墨炉原子吸收法测定铝矾土中的硅

Determination of Silicon in Bauxite by Graphite Furnace Atomic Absorption Spectrometry

通过对照硅在热解石墨管、涂钼及涂钨石墨管中的原子化行为，选用涂钼石墨管和Ｌａ做基体改进剂，石墨炉原子吸收法测定铝矾土中的硅。经铝矾土管理样分析验证，方法可靠。实际样品分析结果与重量法和钼蓝法相符，对质量分数ｗ（ＳｉＯ２）在４％水平的铝矾土进行分析（ｎ＝５），其ＲＳＤ在１２％～１７％。

In this paper, atomization behaviors of Si in pyro coated, molybdenum coated and tungsten coated graphite tubes are evaluated and compared. Molybdenum coated graphite tube shows the best analytical performance. The tube has been used in the determination of Si in bauxites by GF AAS with La as a modifier. The results are in good agreement with those obtained from gravimetry and spectrophotometry with precision of 1.2%～1.7% RSD( n =5).