Determination of Major Elements in Silicate Samples with High Content Strontium and Barium by X-ray Fluorescence Spectrometry
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摘要: 用百分总和检查硅酸盐岩石全分析数据的质量是分析工作者的传统做法,但对于微量元素含量较高的样品,采用X射线荧光光谱法(XRF)进行测定,如果不考虑微量元素的含量及其对主量元素基体效应的影响,往往会使主量元素含量更加偏离真实值。本文针对Sr、Ba含量较高的硅酸盐样品,通过人工配制标准样品,扩大了Sr、Ba校准曲线的定量范围,主量元素校准中加入Sr、Ba的基体校正系数,达到了主量元素定量更加准确可靠的实际效果。采用此方法分析国家标准物质,各主量元素的精密度(RSD)均小于2%;分析不参加回归的标准物质和人工配制的标准样品,主量元素的测量值与标准值(或参考值)基本一致。该方法可以满足硅酸盐的测定要求,主量元素各项结果的加和能够达到《地质矿产实验室测试质量管理规范》的一级标准(99.3%~100.7%)。Abstract: Traditionally, the percentage sum method is used to check the data quality of total analysis of constituents for silicate rock. For samples with a high content of trace elements, the contents of major elements obtained by X-ray Fluorescence Spectrometry (XRF) will deviate from the true values, regardless of trace elements, as will its corresponding matrix effect to the major element. The method described in this paper improves the accuracy of major element content in silicate samples with a high content of Sr and Ba, through extending the calibration curve′s quantitative range of Sr and Ba by Chinese National Standard Materials and artificial standard materials, and applying a matrix correction coefficient of Sr and Ba to the major element calibration procedure. The validity of the method was substantiated by analyzing the national standard materials; the relative standard deviations (RSD) of major elements were less than 2%. Additionally, analysis results of major elements of national standard materials and artificial standard materials, which do not participate in regression were basically in accordance with reference contents. The method can be used to satisfy the analysis of silicate rock and the sum results of all major elements meet the standard of specification of testing quality management for geological laboratories (99.3% to 100.7%).
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Key words:
- silicate /
- major elements /
- strontium /
- barium /
- X-ray Fluorescence Spectrometry
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表 1 XRF仪器分析条件
Table 1. Working conditions of the elements by XRF
元素及谱线 分析晶体 准直器/μm 探测器 电压
U/kV电流
i/mA2θ/(°) PHD范围 峰值 背景1 背景2 Na Kα PX1 550 Flow 32 100 27.8950 -1.8918 2.1214 22~82 Mg Kα PX1 550 Flow 32 100 23.0778 -1.8768 2.1788 20~78 Al Kα PE 002 550 Flow 32 100 144.9836 2.9372 -1.2496 21~76 Si Kα PE 002 550 Flow 32 100 109.1424 -2.3160 1.7938 26~76 P Kα Ge 111 550 Flow 32 100 141.0290 -1.3964 2.8040 23~78 S Kα Ge 111 550 Flow 32 100 110.7464 -1.5162 1.4708 16~74 K Kα LiF 200 150 Flow 32 100 136.7348 -1.1732 2.2190 26~74 Ca Kα LiF 200 150 Flow 32 100 113.1632 -0.8730 1.6258 28~70 Ti Kα LiF 200 150 Flow 40 90 86.2152 -0.6326 0.8640 26~75 Mn Kα LiF 200 150 Duplex 55 66 62.9988 -0.7194 0.7868 13~72 Fe Kα LiF 200 150 Duplex 55 66 57.5302 -0.7132 0.8854 16~69 Cr Kα LiF 200 150 Duplex 55 66 69.3652 -0.6454 0.7386 12~73 Ni Kα LiF 200 150 Duplex 55 66 48.6588 -0.5898 0.8294 18~70 Sr Kα LiF 200 150 Scint 55 66 25.1218 -0.5610 0.7542 22~78 Ba Lα LiF 200 150 Flow 40 90 87.2046 0.6376 - 33~71 Rh KαC LiF 200 150 Scint 55 66 18.4474 - - 26~78 表 2 各元素校准曲线范围
Table 2. Concentration range of elements in the calibration curve
元素 wB/% Na2O 0.01~7.16 MgO 0.008~41.03 Al2O3 0.10~29.26 SiO2 0.62~90.36 P2O5 0.003~0.946 K2O 0.01~7.48 CaO 0.10~53.83 TiO2 0.004~7.69 MnO 0.0039~0.322 Fe2O3 0.155~24.75 SrO 0.0029~2.17 BaO 0.0010~1.49 表 3 方法检出限
Table 3. Detection limit of elements
元素 检出限/(μg·g-1) Na2O 59.22 MgO 38.77 Al2O3 12.88 SiO2 91.36 P2O5 13.13 K2O 24.29 CaO 22.34 TiO2 28.26 MnO 8.52 Fe2O3 6.05 SrO 2.13 BaO 37.18 表 4 方法精密度
Table 4. Precision tests of the method
元素 GBW 07111(n=10) GBW 07131(n=10) wB/% RSD/% wB/% RSD/% Na2O 4.08 0.40 < 0.1 - MgO 2.79 0.31 1.42 0.41 Al2O3 16.79 0.41 1.13 1.02 SiO2 59.83 0.43 6.30 0.51 P2O5 0.34 0.52 0.12 0.90 K2O 3.52 0.27 0.41 0.47 CaO 4.71 0.19 47.37 0.29 TiO2 0.75 0.32 0.047 5.82 MnO 0.095 0.71 0.091 1.04 Fe2O3 6.08 0.21 0.74 0.54 SrO 0.14 0.80 0.055 2.34 BaO 0.21 1.58 1.46 0.43 表 5 分析结果与参考值比对
Table 5. Comparison of analytical results and proposed values in samples
wB/% 元素 GBW 07111 HC-Ba1 HC-Sr2 HC-Sr3 测量值 标准值 测量值 标准值 测量值 标准值 测量值 标准值 Na2O 4.07 4.05 0.027 0.056 0.058 0.060 4.02 3.99 MgO 2.80 2.81 0.74 0.77 0.079 0.080 2.77 2.77 Al2O3 16.69 16.56 2.32 2.33 3.45 3.44 16.37 16.31 SiO2 59.79 59.68 48.46 48.32 88.52 88.27 58.77 58.76 P2O5 0.34 0.34 0.17 0.17 0.22 0.21 0.34 0.33 SO3 0.03 0.03 0.59 0.60 0.21 0.21 0.03 0.03 K2O 3.49 3.50 0.53 0.53 0.64 0.64 3.46 3.45 CaO 4.68 4.72 23.99 24.23 0.28 0.29 4.63 4.65 TiO2 0.74 0.77 0.16 0.15 0.26 0.25 0.74 0.76 MnO 0.094 0.094 0.055 0.055 0.020 0.020 0.094 0.093 Fe2O3 6.09 6.07 1.98 1.98 3.15 3.15 6.00 5.98 SrO 0.15 0.14 0.03 0.03 1.62 1.63 1.18 1.22 BaO 0.22 0.21 0.74 0.75 0.022 0.016 0.21 0.21 表 6 高含量的微量元素Sr、Ba对主量元素结果的影响
Table 6. Effect of Sr and Ba on major elements determination
wB/% 元素 样品1 样品2 样品3 样品4 加入Sr、
Ba校正不加入Sr、
Ba校正加入Sr、
Ba校正不加入Sr、
Ba校正加入Sr、
Ba校正不加入Sr、
Ba校正加入Sr、
Ba校正不加入Sr、
Ba校正Na2O 3.62 3.58 3.65 3.61 4.16 4.12 3.99 3.95 MgO 4.21 4.16 3.42 3.37 3.89 3.84 3.39 3.35 Al2O3 15.45 15.25 14.80 14.6 15.14 14.95 14.97 14.8 SiO2 48.70 48.05 48.35 47.64 49.55 48.88 49.14 48.53 P2O5 1.22 1.20 1.17 1.15 1.21 1.19 1.19 1.18 K2O 3.46 3.40 3.58 3.5 3.00 2.93 3.24 3.18 CaO 4.70 4.61 5.96 5.83 4.58 4.48 5.74 5.64 TiO2 2.80 2.72 2.70 2.62 2.72 2.63 2.70 2.62 MnO 0.17 0.16 0.17 0.16 0.17 0.16 0.16 0.15 Fe2O3 9.88 9.24 9.17 8.51 9.58 8.98 9.13 8.57 SrO 0.21 0.21 0.28 0.28 0.77 0.77 0.22 0.22 BaO 2.22 2.19 2.47 2.44 1.99 1.96 2.09 2.06 LOI 3.28 3.28 3.97 3.97 3.27 3.27 3.82 3.82 总和 99.92 98.05 99.69 97.68 100.03 98.16 99.78 98.07 -
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