Determination Of Iodide In Seawater Research Articles

Poly(ethylene glycol) Methyl Ether Methacrylate-bonded Stationary Phase in Ion Chromatography and Its Application to Seawater Samples.

A fast and simple ion chromatographic method for the determination of iodide in seawater is reported using poly(ethylene glycol) methyl ether methacrylate-bonded stationary phase. Poly(ethylene glycol) methyl ether methacrylate was reacted with primary amino groups of aminopropylsilica in N,N-dimethylformamide at 80°C. The prepared stationary phases were evaluated by analyzing several inorganic anions and the retention behavior was observed. Various chromatographic parameters were optimized for the separation of these anions. Although there were no ion-exchange sites on the resulted stationary phases, the results obtained suggested that an ion-exchange mechanism was involved in the retention of analyte anions. With 0.15 μL injection, the limit of quantitation of iodide was 26 μg L-1 when 200 mM NaCl was selected as the eluent. This stationary phase was applied to the analysis of direct and fast determination of iodide in real seawater samples successfully with the recovery rates of 98.1 and 104.9%.

A portable multi-syringe flow system for spectrofluorimetric determination of iodide in seawater

A miniaturized analyzer encompassing a poly(methyl methacrylate) chip with integrated spectrofluorimetric detection and solutions propelling by a multi-syringe module is proposed. Iodide was determined through its catalytic effect on the reaction between Ce(IV) and As(III). Matrix isopotential synchronous fluorescence was explored to set the excitation and emission wavelengths. A two-level full factorial design allowed to evaluate the significance of variables (Ce(IV), As(III) and H2SO4 concentrations) and their interaction effects in the experimental domain. A Doehlert Matrix was applied to identify the critical values. The optimized procedure showed a linear response from 1 to 100μgL−1 (S=53.7+2.61C, in which S is the net fluorescence and C is iodide concentration in μgL−1). Detection limit, coefficient of variation (n=6) and sampling rate were estimated at 0.3 μgL−1, 0.8% and 20h−1, respectively. Recoveries within 90–117% were estimated for iodide spiked to seawater samples. The proposed procedure stands out because of the portability, robustness, and simplicity for in-field analysis of iodide in seawater.

A miniaturized analyzer for the catalytic determination of iodide in seawater and pharmaceutical samples

A monolithic flow conduit was especially designed and coupled to a multisyringe unit (MSFIA) in order to develop a kinetic analytical method. The new device, denoted CHIP, integrates different functions in a reduced size including confluent mixing, reaction coil, and thermostating, which allowed minimizing the dimensions of the entire analyzer system. The CHIP–MSFIA was satisfactorily applied to the determination of iodide using the Sandell–Kolthoff reaction. The resulting system allows fast, simple and automatic analysis in seawater samples and a pharmaceutical preparation. By the use of an additional syringe, reagent blank, sample blank, unspecific interferences, and sample analyte concentration was evaluated by simply changing the mode of operation. The instrumentation and analytical procedures were optimized in respect of sensitivity. A limit of detection of 4.7μgL−1 and linear working range of 4.3–70μgL−1 were achieved.Two new modes of air bubble elimination were developed and employed in this work, leading to improved reproducibility (RSD %=1.5%) and method robustness. The accuracy of analysis for seawater samples was evaluated by an Add–Recovery test obtaining recoveries between 97 and 106%. For the quantification of iodide in the pharmaceutical sample, standard addition calibration was required. No significant differences between the found and the certified value were found. The entire analytical procedure lasted about 150s enabling a measuring frequency of 23h−1.

Determination of Iodide in Seawater by Capillary Ion Chromatography Using Hexadimethrine Bromide Modified C30 Stationary Phases

A novel and simple capillary ion chromatographic method for the determination of iodide is reported. Separation was achieved on a laboratory-made packed capillary column (100 mm × 0.32 mm i.d.) packed with triacontyl-functionalized silica, followed by a modification with hexadimethrine bromide, where 1 mM sodium chloride-acetonitrile (95:5, v/v) was used as the eluent and UV-absorbing analyte anions were detected at 225 nm. The effects of the eluent composition on the retention behavior of inorganic anions were investigated. The addition of a small amount of an organic substance in an eluent such as acetonitrile increased the retention of iodide, while the addition of methanol decreased its retention. The present analytical method was successfully applied to the rapid and direct determination of iodide in seawater without any preconcentration. Also, this modified column could be used for about two months (6 h operation per day) without hexadimethrine bromide being contained in the eluent.

Rapid determination of iodide in seawater samples by ion chromatography with chemically-bonded vitamin-U stationary phase

A simple and rapid analytical method using a laboratory-made packed column (100mm×0.32mm i.d.) was developed for the determination of iodide in seawater. The stationary phases were prepared by the reaction of the hydroxyl group on the surface of the diol-group bonded silica gel with vitamin U. Simultaneous separation of four common inorganic anions (iodate, nitrate, iodide, and thiocyanate) was achieved within 9min using 0.05mM sulfuric acid–methanol (99:1, v/v) as the eluent. The limit of detection of iodide was 8.2μgl−1 (S/N=3), and the limit of quantification was 27μgl−1 (S/N=10). The RSD values of retention time, peak area and peak height were all smaller than 2.4%. The present analytical method was successfully applied to the rapid and direct determination of iodide in seawater samples collected from Japan coasts, and gave iodide content from 46.8 to 54.1μgl−1, by using a standard addition method. The recoveries of added iodide were from 95.6 to 106.4%. In the present system, the retention of analytes may not be caused by electrostatic interaction, but by hydrophobic interaction.

Determination of iodide in seawater samples by ion chromatography with chemically-bonded poly(ethylene glycol) stationary phase

An ion chromatographic method for the rapid and direct determination of iodide in seawater is reported. Poly(ethylene glycol) (PEG) groups were chemically bonded onto silica gel or C30-bonded silica gel via diol groups. PEG-bonded C30 binary phases allowed determination of iodide in seawater samples without any interference. Effects of eluent composition on retention behavior of inorganic anions have been investigated. Both cation and anion of the eluent affected the retention of analyte anions. The retention time of anions increased with increasing eluent concentration. The detection limit for iodide obtained by injecting 0.2 μl of sample was 13 μg l −1 (S/N = 3) while the limit of quantitation was 43 μg l −1 (S/N = 10). The present method was successfully applied to the rapid and direct determination of iodide in seawater with long-term durability.

Determination of iodide in seawater and edible salt by microcolumn liquid chromatography with poly(ethylene glycol) stationary phase

An ion chromatography method for rapid and direct determination of iodide in seawater and edible salt is reported. Separation was achieved using a laboratory-made C30 packed column ( 100 mm×0.32 mm i.d.) modified with poly(ethylene glycol) (PEG). Effects of eluent composition on retention behavior of inorganic anions have been investigated. Both cation and anion of the eluent affected the retention of analyte anions. The retention time of anions increased with increasing eluent concentration when lithium chloride, sodium chloride, potassium chloride, sodium sulfate, magnesium sulfate were used as the eluent, while it decreased with increasing eluent concentration when ammonium sulfate was used as the eluent. The detection limit for iodide obtained by injecting 0.2 μl of sample was 9 μg/l (S/N = 3). The present method was successfully applied to the rapid and direct determination of iodide in seawater and edible salt samples. Partition may be involved in the present separation mode.

Capillary zone electrophoretic determination of iodide in seawater using transient isotachophoresis with artificial seawater as the background electrolyte.

We describe an application of capillary zone electrophoresis (CZE) with transient isotachophoresis (ITP) as the on-line concentration procedure for the determination of iodide in seawater. The effective mobility of iodide was decreased by the addition of 10 mM cetyltrimethylammonium chloride (CTAC) to an artificial seawater background electrolyte (BGE) so that transient ITP functioned and iodide was separated from other coexisting anions such as bromide, nitrite, and nitrate in seawater samples. After sample injection, 600 mM acetate was separately injected into the capillary as the terminating ion to generate transient ITP. The limit of detection (LOD) for iodide was 3.0 microg/L. The LOD was obtained at a signal-to-noise ratio (S/N) of 3. The values of the relative standard deviation (RSD) of peak area, peak height, and migration time for iodide were 2.9, 2.1, and 0.6%. The proposed method was applied to the determination of iodide in seawater collected around the Osaka Bay. The results obtained by use of the calibration graph were agreed with those obtained by the addition of the standard solutions for iodide.

Rapid and direct determination of iodide in seawater by electrostatic ion chromatography

An electrostatic ion chromatographic (IC) method for rapid and direct determination of iodide in seawater is reported. Separation was achieved using a reversed-phase ODS packed column (250×4.6 mm I.D.) modified by coating with Zwittergent-3-14 micelles, with an eluent comprising an aqueous solution containing 0.2 m M NaClO 4 and 0.3 m M Zwittergent-3-14 and using UV detection at 210 nm. Samples prepared by dissolving NaIO 3, NaNO 2, NaBr, NaBrO 3, NaNO 3, NaI, and NaSCN in artificial or real seawaters were analyzed using this IC system. Nitrite, iodate, bromide, bromate, and nitrate showed very little or no retention, while iodide and thiocyanate were well separated, being eluted within 6 and 16 min, respectively. The detection limit for iodide obtained by injecting 400 μL of sample was 0.011 μ M ( S/ N=3), and the precision values obtained by analyzing samples containing 0.1 or 0.3 μ M iodide in real seawater samples were 2.3% RSD and 1.2% RSD, respectively. Direct determination of iodide in real seawater samples was possible using this proposed IC system.

Determination of iodide in seawater and urine by size exclusion chromatography with iodine–starch complex

A novel method for the determination of iodide by size exclusion chromatography was established. The method was simple and highly sensitive with good precision. Iodide was converted to iodine, then sequestered with starch, and separated from the matrix using a Shim-pack DIOL-150 (250×7.9 mm) size exclusion column with methanol–0.01 mol l −1 aqueous phosphoric acid (10:90, v/v) as mobile phase at 1.2 ml min −1 and UV detection at 224 nm. The calibration graph was linear from 1.0 ng ml −1 to 100.0 ng ml −1 for iodide with a correlation coefficient of 0.9992 ( n=6). The detection limit was 0.2 ng ml −1. The method was successfully applied to the determination of iodide in seawater and urine. The recovery was from 92% to 103% and the relative standard deviation was in the range of 1.5% to 3.7%.

Determination of Iodide in Seawater by Ion Chromatography

A simple and highly sensitive ion chromatographic method with UV detection was developed for iodide (I(-)) in seawater. A high-capacity anion-exchange resin with polystyrene-divinylbenzene matrix was used for both preconcentration and separation of iodide. Iodide in artificial seawater (salinity, 35‰) was trapped quantitatively (98.8 ± 0.6%) without peak broadening on a preconcentrator column and was separated with 0.35 M NaClO(4) + 0.01 M phosphate buffer (pH 6.1). On the other hand, the major anions in seawater, chloride and sulfate ions, were partially trapped (5-20%) and did not interfere in the determination of I(-). The detection limit for I(-) was 0.2 μg/L for 6 mL of artificial seawater. The present method was applied to determination of I(-) (ND - 18.3 μg/L) and total inorganic iodine (I(-) + IO(3)(-) - I, 50.0-52.7 μg/L) in seawater samples taken near Japan.

Direct determination of iodide in seawater by cathodic stripping square wave voltammetry

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect determination of iodide in seawater by cathodic stripping square wave voltammetryGeorge W. Luther, Christina Branson. Swartz, and William J. UllmanCite this: Anal. Chem. 1988, 60, 17, 1721–1724Publication Date (Print):September 1, 1988Publication History Published online1 May 2002Published inissue 1 September 1988https://doi.org/10.1021/ac00168a017RIGHTS & PERMISSIONSArticle Views575Altmetric-Citations150LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (463 KB) Get e-Alerts Get e-Alerts