In this study, a simple but highly sensitive and cost-effective lead isotopic analysis strategy is presented. The design uses liquid spray dielectric barrier discharge plasma-induced chemical vapor generation (LSDBD-CVG) coupled with multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). In this LSDBD-CVG approach, Pb was efficiently converted into volatile species in the presence of 1% (v/v) formic acid, which enhances the signal more than seven times and thus enables high-precision Pb isotopic analysis even at low concentrations. The minimum Pb required per analysis with LSDBD-CVG is ∼16 ng, which is one order of magnitude less than the amount needed for the pneumatic nebulization sample introduction. Pb isotopic fractionation during LSDBD-CVG was observed, but the mass bias could be effectively corrected using ²⁰⁵Tl/²⁰³Tl correction combined with standard-sample bracketing. Under optimized conditions, the external precisions at 20 μg L^–1 of Pb with 8 min acquisition time for ²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb, and ²⁰⁶Pb/²⁰⁴Pb were found to be 35, 90, and 23 ppm (2RSD), respectively. The methodology has been successfully validated by Pb isotopic analysis of solutions standard of NIST 981 and geological reference materials (BCR-2 and BHVO-2). Additionally, the good agreement of the measured Pb isotopic compositions of selected soils and Pb-Zn ore district materials obtained by this method with those obtained by membrane desolvation sample introduction using MC-ICPMS further demonstrates its applicability for real samples. As a green and efficient sample introduction method, LSDBD-CVG offers higher sensitivity and better tolerance of coexisting ions than wet plasma conditions for Pb isotopic analysis. Furthermore, the sampling of Pb and Tl can be achieved simultaneously in LSDBD-CVG, which greatly simplifies the introduction system compared with CVG/gas chromatography-MC-ICPMS. The proposed LSDBD-CVG provides a promising new sample introduction strategy for high-precision isotopic analysis, especially for the analysis of isotopes in microsamples.

中文翻译：

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基于液体喷雾介电势垒放电等离子体诱导化学气相生成的多接收电感耦合等离子体质谱法的灵敏度和高精度铅同位素分析

在这项研究中，提出了一种简单但高度灵敏且具有成本效益的铅同位素分析策略。该设计使用液体喷雾介质阻挡放电等离子体诱导化学蒸汽生成 (LSDBD-CVG) 与多接收器电感耦合等离子体质谱 (MC-ICPMS) 相结合。在这种 LSDBD-CVG 方法中，在 1% (v/v) 甲酸的存在下，Pb 被有效地转化为挥发性物质，这将信号增强了七倍以上，因此即使在低浓度下也能进行高精度的 Pb 同位素分析。使用 LSDBD-CVG 每次分析所需的最低 Pb 为 ~16 ng，这比气动雾化样品引入所需的量少一个数量级。在 LSDBD-CVG 过程中观察到 Pb 同位素分馏，但质量偏差可以使用²⁰⁵ Tl/ ²⁰³ Tl 校正结合标准样品包围。在优化条件下，20 μg L ^–1 Pb的外部精度，²⁰⁸ Pb/ ²⁰⁴ Pb、²⁰⁷ Pb/ ²⁰⁴ Pb 和²⁰⁶ Pb/ ^{204 的}采集时间为 8 分钟发现 Pb 分别为 35、90 和 23 ppm (2RSD)。该方法已通过 NIST 981 溶液标准和地质参考材料（BCR-2 和 BHVO-2）的 Pb 同位素分析成功验证。此外，通过该方法获得的选定土壤和 Pb-Zn 矿区材料的测量 Pb 同位素组成与使用 MC-ICPMS 通过膜去溶剂化样品引入获得的那些具有良好的一致性，进一步证明了其对实际样品的适用性。作为一种绿色高效的样品引入方法，LSDBD-CVG 为 Pb 同位素分析提供了比湿等离子体条件更高的灵敏度和更好的共存离子耐受性。此外，在 LSDBD-CVG 中可以同时实现 Pb 和 Tl 的采样，与 CVG/气相色谱-MC-ICPMS 相比，大大简化了进样系统。所提出的 LSDBD-CVG 为高精度同位素分析提供了一种很有前途的新样品引入策略，特别是对于微量样品中的同位素分析。