X射线荧光光谱分析铸铁中28种元素

对铸铁的X射线荧光光谱分析方法进行系统的研究,包含C、Mg、Al、Si、Mn、P、S、V、Ti、Cr、Co、Ni、Cu、Zn、As、Se、Zr、Nb、Mo、Sn、Nd、Ce、La、W、Pb、Bi、Te、Sb 28种元素进行测定。试验通过利用国内外21块铸铁标准样品拟合成一套铸铁的通用校准曲线,选择合适谱线和测量条件并进行有效的背景扣除,其中,测定P、S、Mn、Co、As受共存元素谱线重叠干扰的校正系数,解决了元素之间谱线重叠干扰的问题;Pb元素选用Lβ₁谱线做分析线,以避免As元素的谱线干扰;Te、Sb、Sn均选用Kα谱线,并采用高分辨狭缝以提高峰背比;C、Mg采用高灵敏狭缝,有效解决了元素间干扰问题及超轻元素、微量杂质元素的检测难题。方法用于铸铁标准样品中主次元素的检测,测定值与认定值相符,各元素测定结果的相对标准偏差(RSD,n=10)均小于1.5%。

Determination of twenty-eight elements in cast iron by X-ray fluorescence spectrometry

A method for determination of 28 elements in cast iron was systematically studied by X-ray fluorescence spectrometry(XRF) including C, Mg, Al, Si, Mn, P, S, V, Ti, Cr, Co, Ni, Cu, Zn, As, Se, Zr, Nb, Mo, Sn, Nd, Ce, La, W, Pb, Bi, Te and Sb. A general calibration curve was fitted for cast iron with a set of 21 cast iron certified reference materials at home and abroad. The proper spectral lines and determination conditions were selected, and the background was effectively deducted. The correction coefficient of spectral overlapping interference by coexisting elements was measured during the determination of P, S, Mn, Co and As, solving the spectral overlapping problem among elements. Lβ₁ line was used for the analysis of Pb to avoid the spectral interference of As. The elements including Te, Sb and Sn were determined with Kα line. Meanwhile, the high resolution slit was adopted to enhance the peak-to-background ratio. C and Mg was determined with high sensitivity slit to eliminate the interference among elements, solving the determination problem of ultralight elements and micro impurities. The proposed method was applied to the determination of major and minor elements in cast iron alloy certified reference materials. The results were consistent with certified values. The relative standard deviations (RSD, n=10) were less than 1.5%.