Capillary electrophoretic determination of sulfite using the zone-passing technique of in-capillary derivatization
Capillary electrophoretic determination of sulfite using the zone-passing technique of in-capillary derivatization
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DOI：
10.1016/s0021-9673(01)01295-x
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发表时间：
2001-11-16
影响因子：
4.1
通讯作者：
Padarauskas, A
中科院分区：
文献类型：
--
作者：
Jankovskiene, G;Daunoravicius, Z;Padarauskas, A
建立了一种新的毛细管电泳法测定亚硫酸盐的方法。所提出的方法是基于在毛细管衍生化。亚硫酸盐与碘使用区带通过技术和形成的碘化物的直接UV检测。通过改变碘的浓度、电解质的pH值和外加电压，确定了分离和衍生化反应的最佳条件。优化的分离在20 mmol l（-1）Tris-HCl电解质（pH 8.5）中进行，使用214 nm处的直接UV检测。实验结果表明，从毛细管阳极端进样碘区的精度明显提高。常见的紫外吸收阴离子如Br-、I-、S_2 O_（3 ~（2-））、NO_3-、NO_2-、SCN-不产生干扰。在1（.）范围内证明了有效校准（r（2）= 0.998）。10（-5）-8（.）10（-4）mol l（-1）亚硫酸盐。检出限（S/N = 3）为2（.）10（-6）mol l（-1）。将该体系应用于葡萄酒中游离亚硫酸盐的测定。葡萄酒样品的回收率在92- 103%范围内。并与碘量滴定法进行了比较。(C)2001 Elsevier Science B. V.保留所有权利。
A new capillary electrophoretic (CE) method was developed for the simple and selective determination of sulfite. The proposed method is based on the in-capillary derivatization. of sulfite with iodine using the zone-passing technique and direct UV detection of iodide formed. The optimal conditions for the separation and derivatization reaction were established by varying concentration of iodine, electrolyte pH and applied voltage. The optimised separations were carried out in 20 mmol l(-1) Tris-HCl electrolyte (pH 8.5) using direct UV detection at 214 nm. Experimental results showed that the injection of the iodine zone from anodic end of the capillary gives significantly better precision. Common UV absorbing anions such as Br-, I-, S2O32-, NO3-, NO2-, SCN- did not give any interferences. Valid calibration (r(2) = 0.998) is demonstrated in the range 1(.)10(-5)-8(.)10(-4) mol l(-1) of sulfite. The detection limit (S/N = 3) was 2(.)10(-6) mol l(-1). The proposed system was applied to the determination of free sulfite in wines. The recovery tests established for wine samples were within the range 92-103%. The CE results were compared with those obtained by iodometric titration technique. (C) 2001 Elsevier Science B.V. All rights reserved.