Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins. For high-Fe/Ti and high-Mg/Ti igneous samples, a three-column procedure was required, whereas a two-column procedure was used for low-Fe/Ti and low-Mg/Ti igneous samples. The Ti isotopes were analysed by MC-ICP-MS, and instrumental mass bias was corrected using a ⁴⁷Ti-⁴⁹Ti double-spike technique. The ⁴⁷Ti-⁴⁹Ti double-spike and SRM 3162a were calibrated using SRM 979-Cr, certificated value ⁵³Cr/⁵²Cr_true = 0.11339. Isobaric interference was evaluated by analysing Alfa-Ti doped with Na, Mg, Ca, and Mo, and results indicate that high concentrations of Na and Mg have no significant effect on Ti isotope analyses; however, Ca and Mo interferences lead to erroneous δ^49/47Ti values when Ca/Ti and Mo/Ti ratios exceed 0.01 and 0.1, respectively. Titanium isotopic compositions were determined for 12 igneous reference materials, BCR-2, BHVO-2, GBW07105, AGV-1, AGV-2, W-2, GBW07123, GBW07126, GBW07127, GBW07101, JP-1, and DTS-2b. Samples yield δ^49/47Ti (‰) of −0.035 ± 0.022, −0.038 ± 0.031, 0.031 ± 0.022, 0.059 ± 0.038, 0.044 ± 0.037, 0.000 ± 0.015, 0.154 ± 0.044, −0.044 ± 0.018, 0.010 ± 0.022, 0.064 ± 0.043, 0.169 ± 0.034, and −0.047 ± 0.025 (relative to OL-Ti, ±2SD), respectively; of which isotopic compositions of DTS-2b, JP-1, GBW07101, GBW07105, GBW07123, GBW07126, and GBW07127 are reported for the first time. Standard Alfa-Ti was analysed repeatedly over a ten-month period, indicating a reproducibility of ±0.047 (2SD) for δ^49/47Ti, similar to the precisions obtained for geochemical reference materials.

中文翻译：

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使用双尖峰 MC-ICP-MS 方法对火成参考材料进行钛同位素分析

Ti 分离是通过使用 Bio-Rad AG 1-X8 阴离子交换和 DGA 树脂的离子交换色谱法实现的。对于高 Fe/Ti 和高 Mg/Ti 火成岩样品，需要三柱程序，而对于低 Fe/Ti 和低 Mg/Ti 火成岩样品，需要使用两柱程序。通过 MC-ICP-MS 分析 Ti 同位素，并使用⁴⁷ Ti- ⁴⁹ Ti 双尖峰技术校正仪器质量偏差。使用SRM 979-Cr 校准⁴⁷ Ti- ⁴⁹ Ti 双钉和 SRM 3162a，认证值⁵³ Cr/ ⁵² Cr _true= 0.11339。通过分析掺有 Na、Mg、Ca 和 Mo 的 Alfa-Ti 来评估等压干扰，结果表明高浓度的 Na 和 Mg 对 Ti 同位素分析没有显着影响；然而，当 Ca/Ti 和 Mo/Ti 比率分别超过 0.01 和 0.1 时，Ca 和 Mo 干扰会导致错误的δ ^49/47 Ti 值。测定了 12 种火成岩参考材料 BCR-2、BHVO-2、GBW07105、AGV-1、AGV-2、W-2、GBW07123、GBW07126、GBW07127、GBW07101、JP-1 和 DTS-2b 的钛同位素组成。样品产量δ ^49/47Ti（‰）为-0.035±0.022，-0.038±0.031，0.031±0.022，0.059±0.038，0.044±0.037，0.000±0.015，0.015，0.154，0.154±0.044，0.044，0.044，0.0444444444444±0.044±0.04.44±0.0±0.0±0.010 n.010 n.44±±0.0 n.44，0.010 n.010 n.44±±0.0 n.0 n.0;分别为 0.034 和 -0.047 ± 0.025（相对于 OL-Ti，±2SD）；其中DTS-2b、JP-1、GBW07101、GBW07105、GBW07123、GBW07126、GBW07127的同位素组成为首次报道。在 10 个月内重复分析标准 Alfa-Ti，表明δ ^49/47 Ti 的重现性为 ±0.047 (2SD)，与地球化学参考材料获得的精度相似。