Abstract (EN):
The use of a laboratory-made iodide ionselective electrode with tubular configuration and based on a crystalline membrane (AgI/Ag2S) as the detector for ion chromatographic determination of iodide in urine and serum is described. A C18 reversed-phase column was coated with N-cetylpyridinium chloride to prepare a low-exchange-capacity analytical column and with hexadecyltrimethylammonium bromide to prepare a concentrator pre-column. A 2.0 ml min(-1) flow rate of deionized water and 0.1 mol l(-1) KNO3 solution was used for the pre-concentration and for the chromatographic separation, respectively. For optimum performance of the detector a background level of iodide was added into the column effluent. A linear relationship (r = 0.9997) between tubular electrode potential (as peak height) and iodide concentration in the range 5-400 mu g l(-1) and a detection limit of 1.47 mu g l(-1) were obtained. The method shows good reproducibility for both peak height (2.2% RSD) and retention time (1.3% RSD). Recoveries on its application to the samples were 93.0-100.9% for urine and 91.4-106.0% for serum.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
6