五酸和硝酸微波消解法结合ICP-OES技术测定多金属矿中多种元素的对比研究

快速、准确测定多金属矿中的主次量元素需要根据多金属矿的具体类型选择不同的预处理方法。本文采集我国典型区域的铅锌、锡、钼、钒和铜镍等5种多金属矿,对比了盐酸-硝酸-高氯酸-氢氟酸-硫酸五酸微波消解和硝酸微波消解的溶样效果,应用电感耦合等离子体发射光谱法(ICP-OES)测定铜铅锌锡钨钼锰钛钒9种元素。通过国家标准物质分析验证,五酸微波消解的溶样时间较长,但一次可测定铜铅锌钼锰钒6种元素;硝酸微波消解的溶样时间短,但一次只能测定铜铅锌钼4种元素;两种方法的准确度和精密度高(RSD5%),检出限低(5.3~30 mg/kg),均适合在地质行业推广应用。而由于锡钨钛3种元素不能完全被酸溶解,上述两种消解方法均不适合。

Determination of Multi-elements in Polymetallic Ores by ICP-OES with Mixed Acids and Nitric Acid Microwave Digestion

Different pretreatment methods should be used for quick and accurate determination of major and minor elements in different types of polymetallic ores. In this study, five types of polymetallic ores including Pb-Zn, Sn, Mo, V, and Cu-Ni polymetallic ores were collected from typical metallogenic areas of China. Comparison of microwave digestion using mixed acids of hydrochloric-nitric-perchloric-hydrofluoric-sulphuric acids with digestion using nitric acid only was performed. Nine elements, Cu, Pb, Zn, Sn, W, Mo, Mn, Ti, and V were determined by the Inductively Coupled Plasma-Optical Emission Spectrometry technique. Analytical results of National Standards Reference indicate that digestion with a mixture of five acids has a long digestion time and can simultaneously determine the 6 elements of Cu, Pb, Zn, Mo, Mn, and V. Digestion with nitric acid needs only 1 h and can determine 4 elements, Cu, Pb, Zn, and Mo. Two methods have good accuracy and precision (RSD<5%) and low detection limits of 5.3-30 mg/kg, which are suitable for application in geological analyses. However, neither of these two methods are suitable for analyzing Sn, W, and Ti, because these elements cannot be digested completely by acids.