| Black rock series are important carriers of various useful elements, and some have abnormally enriched precious metal elements, even with a content exceeding that in some basic and ultrabasic rocks. At present, there are no reference materials available both domestically and internationally for composition analysis of noble metals in black shale. Two such reference materials (HSYY-G1 and HSYY-H2) have been developed in our work with candidate samples taken from Zunyi, Guizhou and Zhuangjiayu, Hunan. Randomly selected samples were used for uniformity and stability tests and the measured values of F were all less than 1.65 for F0.05(29, 60), with relative standard deviations of less than 10%, indicating good sample uniformity. During the stability assessment period, no statistically significant differences were found, suggesting good sample stability. An inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), ultraviolet visible spectrophotometry (COL) and other relatively targeted value determination methods were adopted in several collaborative laboratories to ensure the accuracy of the determination of precious metalsin black shale. This batch of standard materials will be very useful in actual analysis of precious metals in black shale. |
