Standard materials for soil composition analysis

I. Overview

There are 2 soil standard substance meters in this series, mainly used for the comparison plan of geochemical mapping in arid desert areas and the measurement and quality monitoring standards of multi-objective environmental geological survey sample testing.

two、Preparation of samples

The samples were collected from three representative geochemical landscape areas in Xinjiang region (high-altitude mountainous areas, eroded mid low mountain desert areas, and eroded rocky Gobi areas). The distribution areas of gold deposits, copper nickel deposits, tungsten molybdenum deposits, and antimony (gold) deposits in different mineralization zones include the Ashi gold deposit sampling area, the Karatongke copper nickel deposit sampling area, the Karajiaoguya antimony (gold) deposit sampling area, and the Xiaobaishitou tungsten deposit sampling area. The sample is dried, sieved through a 0.25mm or 1mm sieve to remove impurities, mixed, and 120⁰Dry for 24 hours to remove negative water, inactivate, and grind with a high alumina magnetic ball mill to -0.074mm, accounting for over 96%.

three、Uniformity and stability

24 small bottle samples (representing the time error of the samples) were uniformly extracted from different parts of each packaging barrel of each large sample. Each small bottle sample was analyzed in duplicate (representing the error between analyses), and X-ray fluorescence spectrometer was used for measurement. The nested analysis of variance was used to verify the good uniformity of the samples. A bumpy test was conducted on the standard sample, with a bumpy mileage of 10000 kilometers and a duration of 2 months. At the same time, three stability tests were conducted at different times over a year and a half. Molten X-ray fluorescence spectroscopy, ICP-MS, ICP-OES, VOL, AFS were used for determination, and no significant changes were found in the detected elements and components, indicating good stability of the sample.

four、Sample testing

There are a total of 18 main testing methods used. ICP-MS method: acid dissolution determination Ba、Be、Bi、Cd、Ce、Co、Cr、Cs、Cu、Hf、Li、La、Mo、Nb、Ni、Pb、Rb、Sb、Sc、Sr、Ta、Th、Tl、U、V、W、Zn、Sn （Ga、In、Tl）（Y、La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu） Waiting, closed molten ore determination Ba、Li、Be、Sc、V、Cr、Co、Ni、Ca、Ge、Rb、Mo、Cd、In、W、Tl、Pb、B、Bi、Th、S、Cs、U （Br、I） Alkali melting determination of Mn, Co, Y, Zr, Nb, Ba, Hf, Ta, Th, separation determination of Tl, In, Te, etc（Se）Separation and determination of Pt and Pd by gold assay; XRF method: Ba、Br、Ce、Cl、Co、Cr、Cu、Ga、La、Mn、Nb、Ni、P、Pb、Rb、S、Sc、Sr、Th、Ti、V、Y、Zn、Zr、Na₂O、K₂O、MgO、CaO、Fe₂O₃、Al₂O₃、SiO₂；NNA法： Mn、V 、K、La、Na 、Ce、Cr、Cs、Co、Fe、Hf、Rb、Sc、Ta、Th、 I、U、In、 As 、Br、W、Ga； ICP-OES 法： Fe₂O₃、CaO、MgO、K₂O、Na₂O、Ba、Be、Co、Cr、Cu、Li、Mn、Nb、Ni、P、Sc、Sr、Ti、V、Zn； ICP-AES 法：酸溶测定 Fe、Ca、Ti、Nb、Be、Sr、Ba、La、V、Cr、Y、Cu、Zn、Co、Ni、Th、Mn、Al、Mg（Tl）Isothermal determination of 15 rare earth elements and scandium (Zr and Hf) (Nb, Ta, Zr, Hf), alkaline melting determination of SiO₂、Al₂O₃、TFe₂O₃、Na₂O、K₂O、CaO、MgO、TiO₂、MnO、P₂O₅Atomic fluorescence spectroscopy determination: As, Sb, BiHgTheSeTheGe、 Te. Determination of Au by chemical spectroscopy, small fire assay, and assay; determination of Ga, Ag, B, Sn, Pb by emission spectroscopy; ANN method for determinationAgTheTl、 Cd; Determination of K by AAS method₂O、 Na₂O、MgO、 Cu、Zn、Cr、Ni、Co、Ca、Mn； Determination of Cl, Br, and I by ion chromatography; Catalytic colorimetric method for determination of I; Polarographic method for determination of W and Mo; Determination of F by ion selective electrode method; determination by colorimetric methodTFe₂O₃TheTiO₂TheP₂O₅Total carbon and organic carbon method for determining C; Kjeldahl method for determining N; combustion method and gravimetric method for determining S; volumetric method for determining SiO₂TheAl₂O₃TheCaOTheMgOTheFeODetermination of U by laser uranium analyzer method and determination by weight methodL.O.LDetermination of SO by Infrared Analysis Method₃、TC。

5、 Standard value and uncertainty

The basic condition for setting it as a standard value is that there are no less than 8 sets of data, reliable methods with different principles are tested with each other, and the test results are consistent. When the data is small (but not less than 6 sets) or the data is discrete, locate the reference value and represent it with parentheses. The uncertainty (U) of the standard values is listed in the data table）,U=tα·s/Where t α represents the t-value in the t-distribution table, α=0.01, s is the standard deviation, N is the number of data, and when N>20, it is calculated as 20.

6、 Transportation and Storage

The samples are packaged in well sealed polyvinyl fluoride bottles, 70g/bottle and 300g/bottle, tightly sealed with a back cover and stored in a cool place.

7testing unit

Xinjiang Mineral Experimental Research Institute, Langfang Physical and Chemical Exploration Research Institute Testing Center, National Geological Experimental Testing Center, Wuhan Comprehensive Rock and Mineral Testing Center, Chengdu Comprehensive Rock and Mineral Testing Center, Anhui Geological Experimental Research Institute, Shenyang Comprehensive Testing Research Institute, Shandong Comprehensive Testing Research Institute, Henan Rock and Mineral Testing Center, Hunan Rock and Mineral Analysis and Testing Center, Xi'an Comprehensive Rock and Mineral Analysis and Testing Center, Yichang Comprehensive Mineral Research Institute, Chengdu Comprehensive Mineral Research Institute, Qinghai Comprehensive Rock and Mineral Analysis and Testing Center, Xinjiang Nonferrous Testing Center, etc.