Preliminary comparison of inductively coupled plasma mass spectrometry and electrospray mass spectrometry hyphenated with ion chromatography for trace analysis of iodide

Abstract

Ion-exchange chromatography hyphenated with mass spectrometric detection has been investigated for the determination of iodide in urine. Satisfactory chromatographic behavior of iodide could be achieved on a hydrophilic polymer-based anion-exchange column with 35 mM sodium hydroxide as the mobile phase. When electrospray ionization (ESI) was used, a suppressor as well as a flow splitter (split ratio 1 : 10) was required between the column and the interface. In the case of an inductively coupled plasma (ICP) ionization source, eluent and flow-rate were completely compatible with the interface. Under comparable chromatographic conditions, the ESI interface yielded a detection limit of 15 mg L 21 (quadrupole instrument), whereas the ICP interface lowered the detection limits by approximately two (quadrupole instrument) and three (sector field instrument) orders of magnitude. For urine samples both methods gave virtually the same results except for the relative standard deviation, which was 7% for ESI and 0.55% for sector field ICP. The molecule-selective detection of ESI may be an advantage in cases when insufficient separation from other iodine-containing species cannot be avoided. The element-selective ICP will be the preferred tool when iodide has to be determined in the sub-ppb range.

The assessment of iodine status – populations, individuals and limitations

“…29 Mass spectrometry can also be used as a detector in conjunction with liquid or ion chromatography to provide information on iodine species. 31,32 As with all trace element analysis, measurement of iodine is prone to contamination from a variety of sources including urine dipsticks as was recently reported. 33 Urine iodine in populations UI concentration has long been used as the standard means with which to assess the iodine status within a given population.…”

Environmental application of elemental speciation analysis based on liquid or gas chromatography hyphenated to inductively coupled plasma mass spectrometry—A review

“…In a set of seawater samples concentrations of 25.5-29.3 g L −1 for iodate and 27.7-31.6 g L −1 for iodide were determined, respectively. Buchberger and co-workers described the development of an analytical method combining anion-exchange chromatography on a hydrophilic polymer-based stationary phase using 35 mM aqueous NaOH as eluent with either ESI-MS (single quadrupole), ICP-QMS or ICP-SFMS for speciation of iodide in matrix-rich samples [83]. Significantly lower detection limits were obtained with ICP-SFMS (0.01 g L −1 ) and ICP-QMS (0.1 g L −1 ) in comparison with ESI-MS (15 g L −1 ).…”

Development of Standard Reference Materials to support assessment of iodine status for nutritional and public health purposes

“…The most common of the traditional methods is colorimetry based on the Sandell-Kolthoff reaction, in which iodide catalyzes the reduction of ceric ammonium sulfate by arsenious acid (15)(16)(17)(18). The emergence of newer instrumental methods based on coupled ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS) permit measurements of greater specificity and sensitivity, although at higher cost (19)(20)(21)(22).…”