A simple micro-photometric method for urinary iodine determination

Abstract

The modified SK-test takes approximately 90 min for analyses of 20 urine samples compared with 27 h for ICP-MS. The photometric test provides satisfactory results and can be performed with the basic equipment of a clinical laboratory.

Selenium status in patients with autoimmune and non-autoimmune thyroid diseases from four European countries

“…The diagnosis of HT was mainly established by positive thyroid Abs and appropriate findings on thyroid ultrasound. Finally, the GD group included novel GD patients before any treatment (in hyperthyroid condition) with or without GO (19) and GD patients on antithyroid drugs with or without GO (78). GD patients after radioactive iodine therapy or thyroidectomy and now on any type of treatment or off treatment were also included in this group.…”

A Review of Spectrophotometric and Chromatographic Methods and Sample Preparation Procedures for Determination of Iodine in Miscellaneous Matrices

“…Summarizing, future directions of iodine analysis lie rather in the simplification of methodologies and their extensive accessibility rather than in the tendency to decrease the limit of detection. Some recently published papers on the determination of iodine include: the evaluation of urinary iodide by the use of micro-photometric method compared to ICP-MS results (Grimm et al, 2011); determination of iodine and its species in plant samples using IC-ICP/MS (Lin et al, 2011); spectrophotometric determination of I -, IO 3 -, IO 4 -in table salt, pharmaceutical preparations and sea water (George et al, 2011); investigation of the concentration-dependent mobility, retardation, and speciation of iodine in surface sediment from the river (Zhang et al, 2011); comparison of Sandell-Kolthoff reaction with potentiometric measurements of urinary iodide in female thyroid patients (Kandhro et al, 2011). One of the newest studies concerns the analysis of food samples by ICP-MS after alkaline digestion with TMAH (Tinggi et al, 2012).…”

Potentiometric measurement of urinary iodine concentration in patients with thyroid diseases with and without previous exposure to non-radioactive iodine

“…Since ISE-based potentiometry measures exclusively I -, while the SandellKolthoff reaction measures only I 2 , systematically higher UIC in this study was expected. Another possible explanation is that the acid reactant used in the Sandell-Kolthoff reaction might reduce the catalytic activity of I 2 [15,16] and thereby possibly underestimate the real concentration of I 2 in the urine. According to the first hypothesis, to compare the potentiometric I --based UIC expressed in μ g/L to the results of the I 2 -based Sandell-Kolthoff reaction, a division of the UIC potentiometric value (expressed in μ g/L after multiplication for the molecular weight of iodine) for the presumed I -/I 2 ratio in the urine of 9 [12] is necessary.…”

“…Such methods include electrochemical detection, spectrophotometry, chemiluminescence, polarography, mass chromatography, gas chromatography, liquid chromatography and ion chromatography [12 -19] . All these methods have some suboptimal properties [15,16] . For example, analytical methods, particularly inductivity coupled plasma mass spectroscopy, which is often considered the gold standard [14] , is time consuming and requires expensive and complex instrumentation [17] .…”

“…High-performance liquid chromatography methods based on ion chromatography or ion-paired reversed phase separation and detection by amperometry are alternative procedures, but they need special equipment too [18,19] . Photometric methods, most of which make use of the Sandell-Kolthoff reaction, require a pretreatment of the urine sample with acid digestion to remove several organic substances that influence the iodine catalytic effect [15,16] .…”