岩矿测试2026，Vol.45Issue(5)：983-1005,23.DOI:10.15898/j.ykcs.202512300305
地质样品中痕量贵金属的火试金富集与测定技术研究进展
A Review of Research Progress in Fire Assay Preconcentration and Determination Techniques for Trace Precious Metals in Geological Samples
摘要
Abstract
Precious metals,including gold(Au)and platinum-group elements(PGEs),are characterized by extremely low abundances,heterogeneous distribution and susceptibility to the"nugget effect"in natural geological matrices,making their accurate quantitative determination a long-standing challenge in the field of analytical geochemistry.Fire assay(FA)has established itself as one of the primary pretreatment methods for trace precious metal analysis in geological samples,offering distinct advantages such as large sample intake and excellent sample representativeness.The merits and limitations of six prominent fire assay approaches are evaluated in this review:lead,nickel sulfide,bismuth,antimony,tin and copper fire assay.Furthermore,the current research status and mechanisms of cupellation protective agents are discussed and summarized.A critical comparison is presented of the analytical techniques hyphenated with fire assay,including inductively coupled plasma-mass spectrometry(ICP-MS),laser ablation ICP-MS(LA-ICP-MS),inductively coupled plasma-optical emission spectrometry(ICP-OES)and atomic absorption spectrometry(AAS).Among the FA methods,lead,nickel sulfide and antimony fire assay exhibit superior precious metal collection efficiency but are plagued by high toxicity and elevated procedural blanks;moreover,impurity removal and separation from antimony buttons are particularly difficult.In contrast,bismuth and tin fire assay offer low toxicity and low blanks but are constrained by poor button formation integrity(for bismuth)and cumbersome post-processing procedures(for tin).Copper fire assay produces buttons of satisfactory integrity yet results in intractable buttons,severe copper matrix interference and lengthy signal correction procedures.Regarding cupellation protective agents,single precious metal agents improve the enrichment efficiency of specific target elements but are insufficient for the simultaneous determination of multiple precious metals.The incomplete cupellation suffers from poor endpoint controllability and is highly dependent on operator experience.Composite agents enhance the overall protective effect,but they inevitably introduce additional matrix components,increasing the risk of instrumental interferences.In terms of instrumental analysis,ICP-MS provides ultra-high sensitivity and multi-element capability but remains vulnerable to spectral interferences,particularly from polyatomic ions,which can be effectively corrected using collision/reaction cell technologies.LA-ICP-MS eliminates solution-based matrix interferences but is strongly dependent on the availability of matrix-matched reference materials and is still subject to inherent matrix effects and elemental fractionation.ICP-OES features a wide linear dynamic range and strong resistance to spectral interferences but is limited by relatively high detection limits.Conventional line-source AAS offers simple instrumentation and low operational cost but suffers from limited analytical throughput(especially graphite furnace AAS)and poor anti-interference performance.In contrast,novel high-resolution continuum-source AAS exhibits significantly improved anti-interference ability and multi-element analytical efficiency,with increased instrumental complexity and corresponding cost.To this effect,the future development directions of fire assay-based enrichment and determination methods are outlined in this review.Emphasis is placed on the development of green and low-toxicity collectors,the application of solid sampling techniques,full-process automation and the advancement of analytical standardization.关键词
地质样品/贵金属/火试金/铂族元素/灰吹保护剂/原子吸收光谱法Key words
geological samples/precious metals/fire assay/platinum-group elements/cupellation protectant/atomic absorption spectrometry分类
天文与地球科学引用本文复制引用
邵坤,赵改红,赵朝辉..地质样品中痕量贵金属的火试金富集与测定技术研究进展[J].岩矿测试,2026,45(5):983-1005,23.基金项目
深地国家科技重大专项项目(2024ZD1004002) （2024ZD1004002）
四川省科技计划项目(2023YFQ0062) （2023YFQ0062）
