材料期刊网

采用硫化氢分离、深孔电极直流电弧粉末法进行了一种镍基合金中微量有害杂质(Pb,Bi,Sn,Sb,As)的分析。 由于操作流程较长,试剂用量亦较大,即使采用分析纯级试剂实验空白(主要为Pb,Sn,As)也很高。为此系统地分析了空白的来源,并寻找了降低的办法,最后使Pb,Sn的空自值降低至1—2微克。满足了分析的要求。 试样中,As的蒸发很不完全。加入P_2O_5后,使As的蒸发大大加速。由于有效地利用了样品,因而使As的灵敏度提高了4—5倍。实验中发现在As 2349埃处有碳电极在空气中燃弧所产生的带状光谱。 系统实验的结果表明,可以用经过硫化氢沉淀后的纯溶液来配制标准样品,避免了采用一般增量法制定定标曲线,保证了结果的准确度。 通过系统实验,确定了操作条件。对于三个实际试样进行了多次分析。结果说明,本法的分析下限分别为:Pb:0.0001％,Sn,Sb:0.0002％,As:0.0003％,Bi:0.00002％。

A spectro-chemical method, for the analysis of trace of impurity elements (Pb, Bi, Sn, Sb, As) in one kind of Ni-alloys, was developed, with D.C. arc powder excitation following H_2S pre-separation.Owing to the needs of long periods of operation and large amount of reagents, the use of A. R. grade reagents led to a considerable blank value. After using purified reagents, the blanks (for Pb, Sn) were reduced to a μ-gram range.During the arcing of the specimens, the evaporation of arsenic was found to be very imcomplete. The addition of P_2O_5 accelerated its evaporation very obviously. While the sample being utilized efficiently, the sensitivity of arsenic increased 4—5 times. It was noticed that at the position of the line As 2349 (?), the band spectra of carbon ignited in air was very obvious and a correction must be made.Results of experiments showed that standard samples could be prepared by the H_2S treatment of pure standard solutions. The usual blank correction of the matrix could thus be avoided.An analytical procedure was suggested and the results of three specimens were listed. These data showed teat the lower limits of analysis of this method were: Pb:0.0001%, Sn, Sb:0.0002%, As:0.0003% and Bi:0.00002%.