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目前,国际上硼同位素分析方法主要有两类:一类是溶液法,将样品溶解后提纯出硼,用表面热电离质谱(P-TIMS和N-TIMS)或MC-ICP-MS来测量硼同位素比值;另一类是原位分析法,用离子探针或LA-MC-ICP-MS直接对矿物进行原位硼同位素比值测量.硼同位素微区原位分析法不仅避免了溶液法繁杂的化学纯化分离流程,提高了工作效率,而且可以对矿物的环带和微层等进行原位分析,揭示矿物形成的精细过程和条件.利用LA-MC-ICP-MS,采用标准-样品-标准(SSB)交叉法对仪器质量歧视和同位素分馏进行校正,建立了LA-MC-ICP-MS硼同位素微区原位测定方法.对系列硼同位素标准和样品进行了详细的测试,对基质效应进行了检验,分析结果与前人报道值或P-TIMS测定值在误差范围内一致.硼含量较高的IAEAB4和IMRRB1的测试结果分别为δ11B=-8.36‰±0.58‰(2σ,n=50)和δ11B=-12.96‰±0.97‰(2σ,n=57),含硼较低的IAEAB6的测试结果为δ11B=-3.29‰±1.12‰(2σ,n=35),分析精度达到国际同类实验室先进水平,满足地质样品分析要求.对电气石、钠硼解石、硼镁铁矿、板棚石和硼镁石等地质样品的B同位素进行了微区原位测量,分析结果与P-TIMS测定结果在误差范围内一致.
At present, there are mainly two types of boron isotope analysis methods in the world: one is solution method, the sample is dissolved to purify boron, and the boron is measured by surface thermal ionization mass spectrometry (P-TIMS and N-TIMS) or MC-ICP-MS Isotope ratios, and the other is in-situ analysis, which directly measures the in-situ boron isotope ratios of minerals by ion probe or LA-MC-ICP-MS.The boron isotope microinanalysis in situ method not only avoids the complicated solution Chemical purification of the separation process to improve work efficiency, but also on the mineral annulus and micro-layer in situ analysis to reveal the fine process and conditions of mineral formation using LA-MC-ICP-MS, using the standard - the sample - standard (SSB) method was used to calibrate the instrument quality discrimination and isotope fractionation, and a LA-MC-ICP-MS boron isotope microarray in situ determination method was established. The series of boron isotope standards and samples were tested in detail. The results of the analysis are consistent with the reported values of previous reports or the P-TIMS values within the error range.The results of the IAEAB4 and IMRRB1 with higher boron content are respectively δ11B = -8.36 ‰ ± 0.58 ‰ (2σ, n = 50) And δ11B = -12.96 ‰ ± 0.97 ‰ (2σ, n = 57), the lower boron content of IAEAB6 The test result is δ11B = -3.29 ‰ ± 1.12 ‰ (2σ, n = 35), the analytical accuracy reaches the international advanced level of similar laboratories to meet the requirements of geological sample analysis. B isotopes of geological samples such as shale and boehmite were measured in situ and the results were consistent with the results of P-TIMS in the error range.