高频燃烧红外吸收法测定锡锌铅青铜中硫

称取0.3 g纯铜助熔剂于坩埚底部,再称取0.4 g样品,上面覆盖1.0 g钨粒,以钢铁标准样品绘制校准曲线,建立了高频燃烧红外吸收法测定锡锌铅青铜中硫的方法。实验表明,当硫质量分数不大于0.01%时,测定低含量硫时应减去空白值;当硫质量分数大于0.01%时,空白值的影响可忽略。方法检出限为0.000 1%,方法测定下限为0.000 3%。用硫酸钾基准试剂配制的硫标准溶液进行方法验证,结果表明,测定值与理论值一致;按照实验方法测定由紫铜光谱标准样品5#、锡粒、纯锌、纯铅混合配制的锡锌铅青铜合成样品,测定值与理论值基本一致。利用实验方法对锡锌铅青铜样品中硫进行测定,测定结果的相对标准偏差(RSD,n=11)为0.71%~1.5%。按照实验方法在锡锌铅青铜样品中加入硫标准溶液进行加标回收试验,回收率在95%～103%之间。

Determination of sulfur in tin-zinc-lead bronze by high frequency combustion infrared absorption method

0.3 g of pure copper flux was transferred on bottom of crucible followed by adding 0.4 g of sample and 1.0 g of tungsten particles in sequence. The calibration curve was prepared with certified reference materials of steel. The determination method of sulfur in tin-zinc-lead bronze by high frequency combustion infrared absorption method was established. The results showed that the blank value should be deducted for the determination of low-content sulfur (the mass fraction of sulfur was lower than 0.01%). The influence of blank could be ignored when the mass fraction of sulfur was higher than 0.01%. The detection limit was 0.000 1%, and the low limit of determination was 0.000 3%. The sulfur standard solution prepared by certified reference material of potassium sulfate was used for method validation. It was found that the results were consistent with the theoretical values. The synthetic sample of tin-zinc-lead bronze prepared by certified reference material of red copper for spectral analysis (5#), tin particle, pure zinc and pure lead was determined according to the experimental method. The results were consistent with the theoretical values. The content of sulfur in tin-zinc-lead bronze sample was determined by the proposed method, and the relative standard deviations (RSD, n=11) were between 0.71% and 1.5%. The standard solution of sulfur was added into tin-zinc-lead bronze sample for recovery test. The recoveries were between 95% and 103%.