校准曲线和观测方式对电感耦合等离子体原子发射光谱法测定不锈钢中镍、铬和锰的影响

Effect of calibration curve and observation way on the determination of nickel,chromium and manganese in stainless steel by inductively coupled plasma atomic emission spectrometry

装饰装修用不锈钢材料主要为200和300系列不锈钢,其化学元素含量对其性能影响较大,其中镍、铬、锰3种元素扮演着举足轻重的作用,因而能否对这些元素含量准确测定意义重大。不锈钢材料中化学元素含量测试主要依据SN/T2718-2010、GB/T 18705-2002、SN/T 3343-2012标准进行测定,此类方法均运用铁基体匹配的系列混合标准溶液绘制校准曲线、电感耦合等离子体原子发射光谱(ICP-AES)法进行测定。用这种方法绘制校准曲线,实验前期准备工作繁琐,而且用于绘制校准曲线的溶液成分与实际待测样品溶液的成分不完全一致,造成样品中成分测定的不确定度大。因此,实验采用系列不锈钢标准样品绘制校准曲线后测定不锈钢中镍、铬、锰含量,并对比了这两种绘制校准曲线方法和测定时观测方式对测定结果的影响。结果表明,采用系列不锈钢标准样品绘制的校准曲线测定镍、铬、锰的含量,准确性明显优于用单标准溶液(样品)绘制的校准曲线,而且配制方法简单,可以大大缩短检测时间。ICP-AES测定的观测方式对不锈钢成分的测定结果有影响,径向观测比轴向观测更适用于不锈钢中镍、铬、锰含量的测定。

The stainless steel materials for ornament and decoration mainly include 200 and 300 series stainless steel. The properties of steel are greatly affected by the content of chemical elements. The element of nickel, chromium and manganese play an important role. Therefore, the accurate determination of these elements is significant. The determination of chemical elements in stainless steel materials is mainly based on the standards including SN/T 2718-2010, GB/T 18705-2002 and SN/T 3343-2012. In these methods, the calibration curves are plotted using the series mixed standard solution with matching of iron matrix. Then, the contents are determined by inductively coupled plasma atomic emission spectrometry（ICP- AES）. However, the procedures of previous preparation are complicated and time-consuming. Moreover, the compositions in solution for plotting calibration curve are not fully consistent with those in sample solution, resulting in large uncertainty of measurement. Therefore, the content of nickel, chromium and manganese in stainless steel was determined with the calibration curve prepared by series standard samples of stainless steel. These two methods for preparing calibration curve were compared. The effect of observation way on the determination results was investigated. The results showed that the accuracy of calibration curve prepared by series standard samples of stainless steel was much better than prepared by single standard solution （sample）. In addition, the preparation method was simple, which could greatly shorten the detection time. The observation method of inductively coupled plasma atomic emission spectrometry had certain influence on the determination results of stainless steel composition. The radial observation was more suitable for the determination of nickel, chromium and manganese in stainless steel than axial observation.