Quick Search:       Advanced Search
WANG Xue-qiu,ZHANG Qin,BAI Jin-feng,YAO Wen-sheng,LIU Mei,LIU Xue-min,WANG Wei.Comparison of Laboratory Analysis Parameters and Guidelines for Global Geochemical Baselines and Environmental Monitoring[J].Rock and Mineral Analysis,2020,39(1):1-14
View Full Text   View/Add Comment   EndNote   BibTeX   Download reader
Comparison of Laboratory Analysis Parameters and Guidelines for Global Geochemical Baselines and Environmental Monitoring
Received:June 05, 2019  Revised:August 26, 2019
DOI:10.15898/j.cnki.11-2131/td.201906050080
Key words: geochemical datum  mercury  cadmium  tungsten  sampling error  laboratory analysis error
Author NameAffiliation
WANG Xue-qiu Key Laboratory of Geochemical Exploration of Ministry of Natural Resources, Institute of Geophysical and Geochemical Exploration, Chinese Acamedy of Geologcial Sciences, Langfang 065000, China
UNESCO International Centre on Global-scale Geochemistry, Langfang 065000, China 
ZHANG Qin Key Laboratory of Geochemical Exploration of Ministry of Natural Resources, Institute of Geophysical and Geochemical Exploration, Chinese Acamedy of Geologcial Sciences, Langfang 065000, China
UNESCO International Centre on Global-scale Geochemistry, Langfang 065000, China 
BAI Jin-feng Key Laboratory of Geochemical Exploration of Ministry of Natural Resources, Institute of Geophysical and Geochemical Exploration, Chinese Acamedy of Geologcial Sciences, Langfang 065000, China
UNESCO International Centre on Global-scale Geochemistry, Langfang 065000, China 
YAO Wen-sheng Key Laboratory of Geochemical Exploration of Ministry of Natural Resources, Institute of Geophysical and Geochemical Exploration, Chinese Acamedy of Geologcial Sciences, Langfang 065000, China
UNESCO International Centre on Global-scale Geochemistry, Langfang 065000, China 
LIU Mei Key Laboratory of Geochemical Exploration of Ministry of Natural Resources, Institute of Geophysical and Geochemical Exploration, Chinese Acamedy of Geologcial Sciences, Langfang 065000, China
UNESCO International Centre on Global-scale Geochemistry, Langfang 065000, China 
LIU Xue-min Chengdu University of Science and Technology, Chengdu 610059, China 
WANG Wei Key Laboratory of Geochemical Exploration of Ministry of Natural Resources, Institute of Geophysical and Geochemical Exploration, Chinese Acamedy of Geologcial Sciences, Langfang 065000, China
UNESCO International Centre on Global-scale Geochemistry, Langfang 065000, China 
Hits: 125
Download times: 95
Abstract:
      BACKGROUND: Global harmonious high-quality geochemical data and accompanying maps are reference baselines for quantifying future human-induced or natural environmental changes.
OBJECTIVES: To ensure the accuracy of geochemical reference values and analysis data, advices were made for laboratory analysis.
METHODS: The analytical data of Cd, Hg and W from China, USA, Europe and Australia were compared and two analysis data collected 15 years apart from one laboratory in China were also compared.
RESULTS: All of the cadmium analysis data were consistent with a correlation coefficient of 0.96. Mercury was poorly consistent with a correlation coefficient of 0.74, and tungsten was not comparable with a correlation coefficient of 0.56. The analysis results of cadmium were highly consistent because the analysis method was the same and the detection limit was comparable. The consistency of mercury was poor, especially the low-content mercury, which was significantly different due to different analysis methods and detection limits. Tungsten was not comparable due to different laboratory analysis methods. The prerequisite for recognition of environmental changes (RCenv > REsmpl+RDlab) was that the change value must be larger than the value of field sampling error (REsmpl) and laboratory analysis error (RDlab). Therefore, sampling error and laboratory analysis error must be minimized.
CONCLUSIONS: Six general guidelines are proposed. (1) The original sample is separated through a 10-mesh sieve and processed to a particle size of less than 200 mesh using a pollution-free method. (2) A total of 71 elements plus other parameters should be determined by well-established multiple analysis methods, e.g., fused glass bead-XRF for major elements and 4-acids ICP-MS and ICP-OES for minor elements in combination with other methods. (3) The method detection limits must be lower than crustal abundance of the chemical elements and reportable data percentage must be more than 90%. (4) The geochemical reference materials used for quality control should contain the reported certified CRM values for all elements. (5) Analytical relative errors for the triplicate samples should be less than 40% (RD ≤ 40%) if concentration of the element is less than 3 times detection limits, and less than 20% (RD ≤ 20%) for the elements with concentration more than 3 times detection limits as well as major elements, Fe-group elements and toxic metals. (6) The total contents of major elements SiO2, Al2O3, Fe2O3, FeO, MnO, MgO, CaO, Na2O, K2O, TiO2, P2O5, H2O+, CO2, SO2 and organic matters or those of SiO2, Al2O3, Fe2O3, FeO, MnO, MgO, CaO, Na2O, K2O, TiO2, P2O5 and LOI should be at 99.3%-100.7%.