1.湖南省地质调查所，长沙 410116； 2.湖南省湘南地质勘查院，湖南郴州 423000
Determination of sulfur in geological samples by open acid dissolution-inductively coupled plasma optical emission spectrometry
ZHAO Wei1, LI Wuqing1, ZHOU Hong2, WAN Likai1, WANG Wenlin1, XIA Xingping1
1. Geological Survey of Hunan Institute, Changsha 410116, China; 2. Southern Hunan Institute of Geology and Survey, Chenzhou 423000, China
摘要：建立敞口酸溶-电感耦合等离子体发射光谱(ICP-OES)法测定地质样品中硫的方法。采用硝酸-氢氟酸-高氯酸混合酸体系对样品进行消解，用王水溶液(体积比为1∶1)对样品消解后的盐类进行复溶提取，选择181.975 nm谱线作为分析线，采用ICP-OES法测定地质样品中的硫。硫的质量浓度在0～166.67μg/mL(质量分数为0%～42%)范围内与光谱强度线性关系良好，相关系数为0.999 9，方法检出限为0.06 mg/L，超出线性范围的样品可稀释后测定。化探类样品测定结果的相对标准偏差为1.25%～6.99%(n=12)；矿石类样品测定结果的相对标准偏差为1.71%～3.36%(n=12)，两类标准物质测定值均在标准值不确定度范围内。该方法能同时满足硫含量较低的化探类样品和硫含量较高的矿石类样品的测定。经该方法处理的样品溶液，还可用于同时测定K， Na， Ca， Mg， Fe， Al， Ti， V，Mn，Zn，Sr，Ba， Ni等十几种元素，可大幅提高分析效率，值得在地质样品分析中进行推广。该方法不适用于炭质含量较高的样品的测定。
Abstract：A method for the determination of sulfur in geological samples by open acid dissolution-inductively coupled plasma optical emission spectrometry (ICP-OES) was established. The samples were digested with the mixed acid system of nitric acid, hydrofluoric acid and perchloric acid, and the dissolved salts were extracted with aqua regia solution (volume ratio was 1∶1). The 181.975 nm spectral line was used as the analytical line. The sulfur in geological samples was determined by ICP-OES. The mass concentration of sulfur had a good linear relationship with the spectral intensity in the range of 0-166.67μg/ml (mass fraction was 0%-42%), the correlation coef ficient was 0.999 9, and the detection limit of the method was 0.06 mg/L. Samples beyond the linear range could be diluted for determination. The relative standard deviations of the determination results of geochemical exploration samples were 1.25%-6.99%(n=12). The relative standard deviations of the determination results of ore samples were 1.71%-3.36%(n=12), and the determination values of the two type of reference materials were all within the uncertainty range of the standard values. The method could simultaneously meet the determination of sulfur content in low sulfur content geochemical exploration samples and high sulfur content ore samples. The sample solution treated by this method could be used for simultaneous determination of more than ten elements such as K, Na, Ca, Mg, Fe, Al, Ti, V, Mn, Zn, Sr, Ba, Ni, etc., which could greatly improve the ef ficiency of sample analysis, and it was worthy of promotion in geological sample analysis. This method is not suitable for the determination of sulfur in sample with high carbon content.
Keywords：inductively coupled plasma optical emission spectrometry; geochemical sample; ore sample; sulfur
ZHAO Wei，LI Wuqing，ZHOU Hong，et al. Determination of sulfur in geological samples by open acid dissolution-inductively coupled plasma optical emission spectrometry[J]. Chemical Analysis and Meterage，2022，31(7)：63.