On-line chloride removal from ion chromatography for trace-level analyses of phosphite and other anions by coupled ion chromatography-inductively coupled plasma mass spectrometry
On-line chloride removal from ion chromatography for trace-level analyses of phosphite and other anions by coupled ion chromatography-inductively coupled plasma mass spectrometry
复制标题
通过耦合离子色谱-电感耦合等离子体质谱法从离子色谱中在线去除氯化物，用于亚磷酸根和其他阴离子的痕量分析
DOI：
10.1002/rcm.9665
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发表时间：
2023
影响因子：
2
通讯作者：
Baidya A
中科院分区：
文献类型：
--
作者：
Baidya A
离子色谱（IC）与电感耦合等离子体质谱（ICPMS）相结合是测量低浓度阴离子物质（如亚磷酸盐）的理想工具；然而，天然溶液中高浓度的氯离子和其他阴离子可能会对色谱分离和数据质量产生负面影响。我们开发了一种在离子色谱仪内在线去除样品中氯离子的机制，使用一个附加的阀和一个分离柱将氯离子转移到废物中，而亚磷酸盐和大多数其他阴离子被保留。我们将该系统安装在耦合IC/ICPMS系统中（ICS6000和Element 2在中分辨率模式下），并确定了线性度和检测限。此外，我们通过核磁共振测量磷的种类进行比较，作为亚硝酸盐测定的替代方法。结果样品中氯化物被完全去除，亚磷酸盐被保留，可以用IC/ICPMS分析。测定浓度可低至0.003 μmol/L，且在所测范围内线性良好（可达1.615 μmol/L, r2= 0.999）。核磁共振检出限为6.46 μmol/L。结论在线去除机制能有效地简化样品基质。它消除了使用OnGuard柱进行昂贵的前分析样品处理的需要。我们证实IC/ICPMS是测定天然溶液中亚硝酸盐最有效的技术。新的氯离子去除方法也适用于其他阴离子的分析。
RationaleIon chromatography (IC) combined with inductively coupled plasma mass spectrometry (ICPMS) is an ideal tool for measuring low concentrations of anionic species such as phosphite; however, the high concentration of chloride and other anions in natural solutions may negatively impact chromatographic separation and data quality.MethodWe developed an on‐line mechanism of removing chloride from a sample within an ion chromatograph, using an additional valve and a separation column that transfers chloride to waste while phosphite and most other anions are retained. We installed this system in a coupled IC/ICPMS system (ICS6000 and Element 2 in medium‐resolution mode) and determined linearity and detection limits. In addition, we measured phosphorus species by NMR for comparison as an alternative method for phosphite determination.ResultsChloride was fully removed from the samples while phosphite was retained and could be analysed by IC/ICPMS. Concentrations could be measured down to 0.003 μmol/L and possibly less with good linearity over the explored range (up to 1.615 μmol/L;r2= 0.999). In contrast, the detection limit by NMR was 6.46 μmol/L.ConclusionsThe on‐line removal mechanism works well for simplifying sample matrices. It removes the need for costly pre‐analytical sample treatment with OnGuard columns. We confirm that IC/ICPMS is the most powerful technique for quantifying phosphite in natural solutions. The new chloride‐removal method may also be applicable to analyses of other anions.