Test category: In-situ analysis of Lead isotopic composition Test target: pyrite, chalcopyrite, feldspar, galena, etc. Test period: 20-30 work days Requirements: 1, thin sections, thick sections, or polished sections, length ≤ 5 cm, width ≤ 3 cm, thickness ≤ 0.8 cm, analysis spot marked on the reflected light images. 2, measurements can be done either by customer or by our technician. 3, Feldspar Pb concent should be > 5 ppm, and sulfide Pb concent should be > 200 ppm. 4, Sample Hg/Pb should be < 0.2. Please inform us in advance if not. Analytical methods: 1. In-situ Pb isotope analysis of sulfide by using LA-MC-ICP-MS 2. In situ Pb isotope analysis of feldspar by using LA-MC-ICP-MS Data quality: Precision (2SE) depends on sample Pb concent. Feldspar (K-feldspar and alkali feldspar) Pb content > 20 ppm: 208Pb/204Pb<0.05 207Pb/204Pb<0.02 206Pb/204Pb<0.02 Pb concent = 5-20 ppm 208Pb/204Pb: 0.05~0.2 207Pb/204Pb: 0.02~0.06 206Pb/204Pb: 0.02~0.06 Sulfide sulfide Pb concent vary significantly. The following precision is only for sulfide with Pb = 500 ppm. 208Pb/204Pb≈0.018 207Pb/204Pb≈0.007 206Pb/204Pb≈0.007 Galena 208Pb/204Pb<0.008 207Pb/204Pb<0.003 206Pb/204Pb<0.003 Accuracy depends on analytical methods. 208Pb/204Pb≈0.017 207Pb/204Pb≈0.006 206Pb/204Pb≈0.006 Applied standards: