A Potential New Chalcopyrite Reference Material for Secondary Ion Mass Spectrometry Sulfur Isotope Ratio Analysis

Abstract

Chalcopyrite is an important sulfide mineral in many types of ore deposits, but matrix‐matched chalcopyrite reference materials for microanalysis are lacking. A new natural chalcopyrite‐bearing specimen (HTS4‐6) was analysed in this study to investigate its potential as a reference material for microbeam sulfur isotope ratio measurement. Detailed textural examination and major element determination showed that the HTS4‐6 chalcopyrite grains have no growth rim or zoning. A total of 607 sulfur isotope ratio spot measurements with secondary ion mass spectrometry (SIMS) conducted on the cruciform sections, and over 120 randomly selected grains yielded highly consistent sulfur isotope ratio. The intermediate measurement precision for four measurement sessions of the 34S/32S measurement results was better than 0.39‰ (2s). Randomly selected chalcopyrite grains of HTS4‐6 were further analysed by LA‐MC‐ICP‐MS, which gave a mean δ34S value of +0.58 ± 0.38‰ (2s, n = 95). The maximum variance (expressed as intermediate precision from SIMS and LA‐MC‐ICP‐MS measurements) is not worse than 0.39‰ (the SIMS value), indicating that HTS4‐6 chalcopyrite is a potential reference material for in situ microbeam sulfur isotope measurements. The mean δ34S value determined by gas source isotope ratio mass spectrometry (GS‐IRMS) is +0.63 ± 0.16‰ (2s, n = 23), consistent with that derived by LA‐MC‐ICP‐MS, and can represent the recommended value for this potential reference material.

Atomic spectrometry update – a review of advances in environmental analysis

“…Recommended values for d 56 Fe were based on solution MC-ICP-MS analysis whereas d 33 S and d 34 S were determined by IRMS. Li 215 proposed a natural chalcopyrite (HTS4-6) as a RM for in situ S-isotope-ratio microanalysis aer examination by SIMS and LA-MC-ICP-MS. The measurement precision for 34 S/ 32 S from both techniques was <0.39& (2SD).…”

A new synthesis scheme of pyrite and chalcopyrite reference materials for in situ iron and sulfur isotope analysis using LA-MC-ICP-MS

“…[1][2][3] Measurements of the 56 Fe/ 54 Fe ratio or 34 S/ 32 S ratio in suldes have been used as important tools in studies, such as tracers of ore-forming material sources or global biogeochemical cycling. [4][5][6][7][8][9][10][11] The microanalysis of Fe and S isotope ratios can be conducted by LA-MC-ICP-MS, which provides great advantages over conventional bulk analytical techniques, [12][13][14][15][16][17][18][19][20][21] including the absence of sample preparation, efficient sample introduction, high sample throughput and the ability to distinguish the isotope variations on the scale of micrometers. [22][23][24][25][26][27][28][29][30][31] However, the accurate determination of Fe and S isotope ratios is limited by the inherent problems of LA-MC-ICP-MS, such as isotopic fractionation and matrix effect.…”

“…40) and JC-Po, 17 pentlandite JC-Pn, 17 State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, PR China. E-mail: tuyaken@hotmail.com; Fax: +86-27-67885096; Tel: +86-27-67885096 † Electronic supplementary information (ESI) available: (A) The photographs of chalcopyrite HTS4-6, 20 GC, 14 Cpy-1 (ref. 14) and TC1725 (ref.…”

New Potential Sphalerite, Chalcopyrite, Galena and Pyrite Reference Materials for Sulfur Isotope Determination by Laser Ablation‐MC‐ICP‐MS

“…At present, several in-house sulfide mineral reference materials have been produced by different microbeam laboratories for sulfur isotope determination, including pressed powder pellets (Bühn et al 2012, Pribil et al 2015, natural minerals (Gilbert et al 2014, Li et al 2018b, Li et al 2020, Bao et al 2021 and other artificial solid reference materials (Chen et al 2017). Natural minerals with homogeneous isotopic compositions are the optimal option when measuring natural samples, since their chemical and physical properties are as close as possible.…”

“…Other solid natural mineral references have also been developed for in situ sulfur isotope ratio measurement, such as chalcopyrite HTS4‐6, pyrrhotite JC‐Po and pentlandite JC‐Pn for SIMS (Li et al . 2020, Chen et al . 2021), and pyrite Py‐4, chalcopyrite TC1725 and baryte YF‐2 for LA‐MC‐ICP‐MS (Yuan et al .…”