辉光放电发射光谱法测定钢板镀锌层中铅镉铬

通过条件试验,确定了辉光放电发射光谱仪(GD-OES)的最佳分析参数为:分析功率30 W、氩气气压620 Pa、预溅射时间200 s、积分时间10 s。选用多种基体标准样品,通过溅射率校正建立校准曲线,定量分析镀锌板镀层中铅、镉、铬元素含量及分布状况,得到镀锌层中各元素随深度变化的分析谱图,方法定义了镀层中元素积分计算方法,从而得到镀层中铅、镉、铬元素含量。以纯锌标准样品进行检出限测定,各元素的检出限分别为3.65(铅)、1.33(镉)、0.21(铬) μg/g;以纯锌标准样品进行短期精密度考察,3个元素测定结果的相对标准偏差(RSD, n=15)分别为2.8%(铅)、1.3%(镉)、6.6%(铬)。制备了典型涂镀样板,采用实验方法进行测定,并采用电感耦合等离子体质谱法进行比对分析,结果一致性较好。实验方法适用于快速定量测定钢表面1～50 μm厚度的镀锌板镀层中铅、镉、铬元素含量。

Determination of lead,cadmium and chromium in galvanized layer of steel plate by glow discharge optical emission spectrometry

The optimal analytical parameters of glow discharge optical emission spectrometer (GD OES) were obtained as follows by condition experiments: the analytical power of 30 W, the argon pressure of 620 Pa, the pre sputtering time of 200 s and the integral time of 10 s. The calibration curve was established by the correction of sputtering rate with several matrix certified reference materials. The content and distribution of lead, cadmium and chromium in galvanized layer of steel plate were quantitatively analyzed. The analytical spectra of elements in galvanized layer with the change of depth were obtained. The integral computation method of elements in galvanized layer was defined by the proposed method to determine the content of lead, cadmium and chromium. The detection limit of method was determined with pure zinc certified reference materials. It was found that the detection limit of lead, cadmium and chromium was 3.65, 1.33 and 0.21 μg/g, respectively. The short term precision was investigated by determination of pure zinc certified reference materials, and the relative standard deviation (RSD, n=15) for lead, cadmium and chromium was 2.8%, 1.3% and 6.6%, respectively. The typical galvanized steel plate was prepared and determined by the experimental method. The results were well consistent with those obtained by inductively coupled plasma mass spectrometry. The proposed method was applicable for the rapid and quantitative determination of lead, cadmium and chromium in galvanized layer (thickness of 1-50 μm) on the surface of steel plate.