碱性氢化物发生原子吸收法测定钢铁中的微量铅

采用碱性氢化物体系发生原子吸收方法测定了钢铁中的微量铅.选择铁氰化钾-酒石酸钠为氢化物发生的氧化剂和配位剂,还原剂硼氢化钾的质量浓度为1g,L,测定液中氢氧化钠的质量浓度为3.6g/L,用12.5g/L的草酸酸化,方法特征浓度为0.073ng/mL,检出限为0.20ng/mL.此体系允许2.5 mL测定液中含铁、钴、镍的量为30,3,3 mg,可以满足直接测定钢铁中的微量铅的需要.通过对含铅0.002%(质量分数)的样品测定实验,得到了满意的结果.

Pb Determination in Iron and Steel Utilizing Hydride Generation from Alkaline Solution by Atomic Absorption Spectrometry

The hydride generation of Pb from alkaline solution by atomic absorption spectrometry was studied. The K₃Fe(CN)₆ and sodium tartaric were used as oxidant and coordinate agent, and the mass concentrations of NaOH and KBH₄ in the test solution were 3.6 g/L and 1 g/L respectively. The test solution was acidified with 12.5 g/L oxalic acid to generate the hydride of Pb. The sensitivity and detection limit were 0.073 ng/ mL and 0.20 ng/ mL, respectively. The allowable values of Fe, Co, Ni in the test solution of 25 mL were 30, 3, 3 mg with this system, and it was enough to determine Pb in iron and steel without seperation of the matrix. The method was experimentally used to determine Pb in iron and steel with a satisfactory result.