Krata Agnieszka, Kontozova-Deutsch Velichka, Bencs László, Deutsch Felix, Van Grieken René
Micro and Trace Analysis Centre, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium.
Talanta. 2009 Jun 30;79(1):16-21. doi: 10.1016/j.talanta.2009.02.044. Epub 2009 Mar 5.
For the isocratic ion chromatography (IC) separation of low-molecular-mass organic acids and inorganic anions three different anion-exchange columns were studied: IonPac AS14 (9 microm particle size), Allsep A-2 (7 microm particle size), and IC SI-50 4E (5 microm particle size). A complete baseline separation for all analyzed anions (i.e., F(-), acetate, formate, Cl(-), NO(2)(-), Br(-), NO(3)(-), HPO(4)(2-) and SO(4)(2-)) in one analytical cycle of shorter than 17 min was achieved on the IC SI-50 4E column, using an eluent mixture of 3.2mM Na(2)CO(3) and 1.0mM NaHCO(3) with a flow rate of 1.0 mL min(-1). On the IonPac AS14 column, it was possible to separate acetate from inorganic anions in one run (i.e., less than 9 min), but not formate, under the following conditions: 3.5mM Na(2)CO(3) plus 1.0mM NaHCO(3) with a flow rate of 1.2 mL min(-1). Therefore, it was necessary to adapt a second run with a 2.0mM Na(2)B(4)O(7) solution as an eluent under a flow rate of 0.8 mL min(-1) for the separation of organic ions, which considerably enlarged the analysis time. For the Allsep A-2 column, using an eluent mixture of 1.2mM Na(2)CO(3) plus 1.5mM NaHCO(3) with a flow rate of 1.6 mL min(-1), it was possible to separate almost all anions in one run within 25 min, except the fluoride-acetate critical pair. A Certified Multianion Standard Solution PRIMUS for IC was used for the validation of the analytical methods. The lowest RSDs (less than 1%) and the best LODs (0.02, 0.2, 0.16, 0.11, 0.06, 0.05, 0.04, 0.14 and 0.09 mg L(-1) for F(-), Ac(-), For(-), Cl(-), NO(2)(-), Br(-), NO(3)(-), HPO(4)(2-) and SO(4)(2-), respectively) were achieved using the IC SI-50 4E column. This column was applied for the separation of concerned ions in environmental precipitation samples such as snow, hail and rainwater.
为了对低分子量有机酸和无机阴离子进行等度离子色谱（IC）分离，研究了三种不同的阴离子交换柱：IonPac AS14（粒径9微米）、Allsep A-2（粒径7微米）和IC SI-50 4E（粒径5微米）。使用3.2mM Na₂CO₃和1.0mM NaHCO₃的洗脱液混合物，流速为1.0 mL min⁻¹，在IC SI-50 4E柱上，在短于17分钟的一个分析周期内实现了对所有分析阴离子（即F⁻、乙酸根、甲酸根、Cl⁻、NO₂⁻、Br⁻、NO₃⁻、HPO₄²⁻和SO₄²⁻）的完全基线分离。在IonPac AS14柱上，在以下条件下：3.5mM Na₂CO₃加1.0mM NaHCO₃，流速为1.2 mL min⁻¹，可以一次运行（即少于9分钟）将乙酸根与无机阴离子分离，但不能分离甲酸根。因此，有必要采用第二次运行，以2.0mM Na₂B₄O₇溶液作为洗脱液，流速为0.8 mL min⁻¹来分离有机离子，这大大延长了分析时间。对于Allsep A-2柱，使用1.2mM Na₂CO₃加1.5mM NaHCO₃的洗脱液混合物，流速为1.6 mL min⁻¹，在25分钟内可以一次运行分离几乎所有阴离子，除了氟化物 - 乙酸根关键对。使用IC认证的多阴离子标准溶液PRIMUS对分析方法进行验证。使用IC SI-50 4E柱实现了最低的相对标准偏差（小于1%）和最佳的检测限（F⁻、Ac⁻、For⁻、Cl⁻、NO₂⁻、Br⁻、NO₃⁻、HPO₄²⁻和SO₄²⁻分别为0.02、0.2、0.16、0.11、0.06、0.05、0.04、0.14和0.09 mg L⁻¹）。该柱用于分离雪、冰雹和雨水等环境降水样品中的相关离子。
