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Fast and simple method for determination of iodide in human urine, serum, sea water, and cooking salt by capillary zone electrophoresis
Author(s) -
Pantůčková Pavla,
Křivánková Ludmila
Publication year - 2004
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200305805
Subject(s) - seawater , iodide , capillary electrophoresis , chemistry , chromatography , polyethylenimine , detection limit , capillary action , salt (chemistry) , analytical chemistry (journal) , inorganic chemistry , materials science , biochemistry , organic chemistry , transfection , oceanography , composite material , gene , geology
For the determination of iodide in urine, where 80–90% of consumed iodine is excreted, a fast, simple, and sensitive method of capillary zone electrophoresis was elaborated and tested also for additional complex matrices such as human serum, cooking salt, and seawater. Several approaches were examined for the separation of iodide from other macro‐ and microcomponents in the tested matrices, and the best results were obtained when host‐guest interaction with α‐cyclodextrin or ion‐pairing with polyethylenimine was employed. In both cases comparable resolution and sensitivity were reached. Due to the relatively high price of cyclodextrin only the method with polyethylenimine was further optimized and a simple procedure enabling the determination of iodide in untreated human urine, serum, cooking salt, and seawater was elaborated. The samples were injected for 20 s at 0.5 psi (3.45 kPa) into a fused‐silica capillary (0.18 mm ID, 50 cm effective length) coated with polyacrylamide (electroosmotic flow < 2×10 −9 m 2 V −1 s −1 ) and filled with the optimized background electrolyte composed of 20 m M KH 2 PO 4 and 0.7% m/v polyethylenimine. For detection, UV absorption at 200 and 230 nm was measured. Concentration limits of detection reached at 230 nm were for human urine 0.14 μ M , for human serum 0.17 μ M , for seawater 0.17 μ M , and for cooking salt 89 n M . Relative standard deviations of iodide peak area and height in all matrices ranged within 0.93 to 4.19%.