Showing papers on "Iodine published in 2004"

Sources of dietary iodine: bread, cows' milk, and infant formula in the Boston area.

Abstract: Dietary iodine is essential for thyroid hormone production. Although U.S. dietary iodine is generally adequate, some groups, especially women of childbearing age, are at risk for mild iodine deficiency. Children’s average urinary iodine is higher than that of adults. U.S. dietary iodine sources have not been assessed recently. A survey of iodine content in 20 brands of bread, 18 brands of cows’ milk, and eight infant formulae was performed between 2001 and 2002. Three bread varieties contained more than 300 μg iodine per slice. Iodine content in other brands was far lower (mean ± sd, 10.1 ± 13.2 μg iodine/slice). All cows’ milk samples had at least 88 μg iodine/250 ml, ranging from 88–168 μg (116.0 ± 22.1 μg/250 ml). Infant formulae values ranged from 16.2 to 56.8 μg iodine/5 oz (23.5 ± 13.78 μg/5 oz). The public should be aware of the need for adequate dietary iodine intake and should be aware that ingredient lists do not reflect the iodine content of foods.

Synergistic Influence of Poly(4-Vinylpyridine) and Potassium Iodide on Inhibition of Corrosion of Mild Steel in 1M HCl

Abstract: The corrosion and inhibition behavior of mild steel in 1 M HCl in the presence of poly(4-vinylpyridine)(P4VP) and potassium iodide (KI) was investigated using weight loss measurements, potentiodynamic polarization studies and impedance measurements. The inhibition efficiency increased with increasing P4VP concentration. The inhibiting action of P4VP is considerably enhanced by the addition of potassium iodide. The adsorption of this compound either alone or in combination with iodide ions on the metal surface is found to obey Lamgmir's adsorption isotherm. The experimental results suggest that the presence of iodide ions in the solution increases the surface coverage Θ and, therefore, indicate the joint adsorption of P4VP and iodide ions. On the other hand, it was found that the inhibiting effect of P4VP and (P4VP + KI) increased with increasing temperature of the corrosion medium. The presence of these species in the solution decreases the double layer capacitance and increases the charge transfer resistance, both derived from Nyquist plots obtained from a.c. impedance studies. The variation of charge transfer resistance with time suggests that the inhibitive action of (P4VP + KI) depends mainly on the protective inhibitor film formed on the steel surface.

Ambient temperature plastic crystal electrolyte for efficient, all-solid-state dye-sensitized solar cell.

Abstract: Doping the molecular plastic crystal of succinonitrile with solid N-methyl-N-butylpyrrolidinium iodide salt and iodine has produced a highly conductive solid iodide/triiodide conductor. Furthermore, it was employed for a highly efficient, all-solid-state dye-sensitized solar cell.

Transient hypothyroidism or persistent hyperthyrotropinemia in neonates born to mothers with excessive iodine intake.

Abstract: Perinatal exposure to excess iodine can lead to transient hypothyroidism in the newborn. In Japan, large quantities of iodine-rich seaweed such as kombu (Laminaria japonica) are consumed. However, effects of iodine from food consumed during the perinatal period are unknown. The concentration of iodine in serum, urine, and breast milk in addition to thyrotropin (TSH), free thyroxine (FT(4)), and thyroglobulin was measured in 34 infants who were positive at congenital hypothyroidism screening. Based on the concentration of iodine in the urine, 15 infants were diagnosed with hyperthyrotropinemia caused by the excess ingestion of iodine by their mothers during their pregnancy. According to serum iodine concentrations, these infants were classified into group A (over 17 microg/dL) and group B (under 17 microg/dL) of serum iodine. During their pregnancies these mothers consumed kombu, other seaweeds, and instant kombu soups containing a high level of iodine. It was calculated that the mothers of group A infants ingested approximately 2300-3200 microg of iodine, and the mothers of group B infants approximately 820-1400 microg of iodine per day during their pregnancies. Twelve of 15 infants have required levo-thyroxine (LT(4)) because hypothyroxinemia or persistent hyperthyrotropinemia was present. In addition, consumption of iodine by the postnatal child and susceptibility to the inhibitory effect of iodine may contribute in part to the persistent hyperthyrotropinemia. We propose that hyperthyrotropinemia related to excessive iodine ingestion by the mother during pregnancy in some cases may not be transient.

Toxicological profile for iodine

Abstract: DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. A Toxicological Profile for Iodine, Draft for Public Comment was released in September 2001. This edition supersedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary. For information regarding the update status of previously released profiles, contact ATSDR at: vi Background Information The toxicological profiles are developed by ATSDR pursuant to Section 104(i) (3) and (5) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA or Superfund) for hazardous substances found at Department of Energy (DOE) waste sites. CERCLA directs ATSDR to prepare toxicological profiles for hazardous substances most commonly found at facilities on the CERCLA National Priorities List (NPL) and that pose the most significant potential threat to human health, as determined by ATSDR and the EPA. ATSDR and DOE entered into a Memorandum of Understanding on November 4, 1992 which provided that ATSDR would prepare toxicological profiles for hazardous substances based upon ATSDR=s or DOE=s identification of need. The current ATSDR priority list of hazardous substances at DOE NPL sites was announced in the Toxicological Profiles are a unique compilation of toxicological information on a given hazardous substance. Each profile reflects a comprehensive and extensive evaluation, summary, and interpretation of available toxicologic and epidemiologic information on a substance. Health care providers treating patients potentially exposed to hazardous substances will find the following information helpful for fast answers to often-asked questions. Chapter 1: Public Health Statement: The Public Health Statement can be a useful tool for educating patients about possible exposure to a hazardous substance. It explains a substance's relevant toxicologic properties in a nontechnical, question-and-answer format, and it includes a review of the general health effects observed following exposure. Chapter 3: Health Effects: Specific health effects of a given hazardous compound are reported by type of health effect (death, systemic, immunologic, reproductive), by route of exposure, and by length of exposure (acute, intermediate, and chronic). In addition, both human and animal studies are reported in this section. NOTE: Not all health effects reported in this section are necessarily observed in the clinical setting. Please refer to the Public Health Statement to identify general health effects observed following exposure. The following additional material can be ordered through the ATSDR Information Center: IODINE viii Case …

Prevalence of maternal dietary iodine insufficiency in the north east of England: implications for the fetus

Abstract: Background: Maternal subclinical hypothyroidism is a cause of poor neurodevelopment outcome in the offspring. Although iodine deficiency is the most common cause of hypothyroidism world wide, there are no screening programmes for it in the United Kingdom where the population is assumed to be iodine replete. Objective: To determine the prevalence of reduced iodine intake by measuring urinary iodide concentrations in pregnant and non-pregnant women from the north east of England. Methods: Urinary iodide excretion (UIE) rate was estimated using inductively coupled mass spectrometry in 227 women at 15 weeks gestation and in 227 non-pregnant age matched controls. A reduced intake of iodine is indicated by a concentration in urine of less than 50 μg/l or less than 0.05 μg iodine/mmol creatinine. Results: Eight (3.5%) pregnant women and 13 (5.7%) controls had a reduced iodine/creatinine ratio. These values were higher when UIE was expressed as iodine concentration: 16 (7%) and 20 (8.8%) respectively. Ninety (40%) of the pregnant women had a UIE of 0.05–0.10, which is consistent with borderline deficiency. Conclusion: In this study, 3.5% of pregnant women had evidence of iodine deficiency, and 40% may be borderline deficient. Larger scale studies are required to estimate the true prevalence of iodine deficiency in the United Kingdom.

A survey of iodine content in Laminaria digitata

Abstract: Laminaria digitata sporophytes sampled from eight Eu-ropean populations (five in Brittany, one in Helgoland,two in the Shetland Islands) were measured for theiriodine levels. The average iodine contents were highestin late autumn and in winter (in the range 0.75–1.20%dw) and were lowest in summer (0.25–0.60%). Youngerplants were richer in iodine, with maxima close to 5% ofdry weight for plantlets. Tissue-specific differences in therates of uptake of iodine correlated with haloperoxidaseactivity, but not with the iodine contents. Keywords: haloperoxidase; iodine; Laminaria ; oxidativestress. Introduction The total iodine concentration in the open ocean isaround 0.5 m M , i.e., approximately 0.06 ppm. The majoriodine species in coastal sea waters are iodate (IO 3y ) andiodide (I y ), along with smaller concentrations of molec-ular iodine, hypoiodous acid and iodinated organic com-pounds (Truesdale et al. 1995). The iodine contents ofmembers of the Laminariales, an average of 1.0% of dryweight in

Iodine nutrition improves in Latin America.

Abstract: Iodine deficiency has been a public health problem in most Latin American countries. Massive programs of salt iodization have achieved great progress toward its elimination but no consistent monitoring has been applied. We used the ThyroMobil model to visit 163 sites in 13 countries and assess randomly selected schoolchildren of both genders 6-12 years of age. The median urinary iodine concentration (8208 samples) varied from 72 to 540 microg/L. One national median was below the recommended range of 100-200 microg/L; five were 100-200 microg/L, and seven were higher than 200 microg/L, including three greter than 300 microg/L. Urinary iodine concentration correlated with the iodine content of salt in all countries. Median values of thyroid volume were within the normal range for age in all countries, but the goiter prevalence varied markedly from 3.1% to 25.0% because of scatter. The median iodine content of salt from local markets (2734 samples) varied from 5.9 parts per million (ppm) to 78 ppm and was greater than 15 ppm in 83.1% of all samples. Only seven countries had higher than 15 ppm iodine in 80% of the samples, and only three had greater than 15 ppm in at least 90%. Iodized salt was available at retail level in all countries but its median iodine content was within the recommended range (20-40 ppm) in only five. This study, the first to apply a standardized assessment strategy to recent iodine nutrition in Latin America, documents a remarkable success in the elimination of iodine deficiency by iodized salt in all but 1 of the 13 countries. Some iodine excess occurs, but side effects have not been reported so far, and two countries have already decreased their legal levels of salt iodization and improved the quality control of iodized salt, in part because of our results. The present work should be followed by regular monitoring of iodine nutrition and thyroid function, especially in the countries presently exposed to iodine excess.

Inorganic iodine speciation in tropical Atlantic aerosol

Abstract: [1] The inorganic speciation of soluble iodine has been determined in size-fractionated aerosol samples collected from the tropical Atlantic Ocean in October/November 2002 during Meteor cruise 55, a pilot study of the German SOLAS programme. Iodide concentrations were appreciable (>0.4 pmol m−3) in the fine and coarse modes of all samples whereas iodate was occasionally below detection limit (∼0.7 pmol m−3) in samples from northern hemisphere air and was undetectable in all samples from the southern hemisphere. Iodine was enriched, and chlorine and bromine depleted, relative to seasalt concentrations. The majority of Cl− loss was due to the seasalt displacement reaction. Halogen activation (I− + HOX + H+ = IX + H2O) may also have occurred, but did not result in net I− depletion in any aerosol fraction. The observed variations of iodine speciation cannot be reproduced by current models of aerosol iodine chemistry.

Valproic Acid Induces the Expression of the Na+/I- Symporter and Iodine Uptake in Poorly Differentiated Thyroid Cancer Cells

Abstract: In poorly differentiated thyroid cancer, molecular characteristics are reported to be lost such as to cause insensitivity of the tumor to radiometabolic therapy. Considerable work is in progress to identify compounds that redifferentiate thyroid cancer cells. The present study evaluates the action of valproic acid, a potent anticonvulsant recently reported to inhibit histone deacetylase, on cultured thyroid cancer cells. N-PA (poorly differentiated) and ARO (anaplastic) cells were treated with increasing valproic acid concentrations; expression of mRNA and cell localization pattern for the Na + /I - symporter (NIS), as well as 125 I uptake, were evaluated before and after treatment. Valproic acid induced NIS gene expression, NIS membrane localization and iodide accumulation in N-PA cells; it was effective at clinically-safe doses in the therapeutic range. In ARO cells, only induction of NIS mRNA was observed, and was not followed by any change in iodide uptake. Valproic acid is thus effective at restoring the ability of N-PA cells to accumulate iodide and its use in clinical trials may be recommended.

Long-Term Radioiodine Retention and Regression of Liver Cancer after Sodium Iodide Symporter Gene Transfer in Wistar Rats

Abstract: Radioiodine therapy of nonthyroid cancers after sodium iodide symporter (NIS) gene delivery has been proposed as a potential application of gene therapy. However, it seems to be precluded by the rapid efflux of taken up iodine from most transduced xenografted tumors. We present an in vivo kinetic study of NIS-related hepatic iodine uptake in an aggressive model of hepatocarcinoma induced by diethylnitrosamine in immunocompetent Wistar rats. We followed the whole-body iodine distribution by repeated imaging of live animals. We constructed a rat NIS (rNIS) adenoviral vector, Ad-CMV-rNIS, using the cytomegalovirus (CMV) as a promoter. Injected in the portal vein in 5 healthy and 25 hepatocarcinoma-bearing rats and liver tumors in 9 hepatocarcinoma-bearing rats, Ad-CMV-rNIS drove expression of a functional NIS protein by hepatocytes and allowed marked (from 20 to 30% of the injected dose) and sustained (>11 days) iodine uptake. This contrasts with the massive iodine efflux found in vitro in human hepatic tumor cell lines. In vivo specific inhibition of NIS by sodium perchlorate led to a rapid iodine efflux from the liver, indicating that the sustained uptake was not attributable to an active retention mechanism but to permanent recycling of the effluent radioiodine via the high hepatic blood flow. Radioiodine therapy after Ad-CMV-rNIS administration achieved a strong inhibition of tumor growth, the complete regression of small nodules, and prolonged survival of hepatocarcinoma-bearing rats. This demonstrates for the first time the efficacy of NIS-based radiotherapy in a relevant preclinical model of nonthyroid human carcinogenesis.

Do iodine-containing contrast media induce clinically relevant changes in thyroid function parameters of euthyroid patients within the first week?

Abstract: Little is known about the reaction of normal thyroid glands to the iodine load given by x-ray dyes. We have therefore investigated the short-term effects of high doses of iodine on thyroid parameters in euthyroid patients. We measured free triiodothyronine (FT3), free thyroxine (FT4), and thyrotropin (TSH) serum concentrations before and daily for 1 week after parenteral application of x-ray dyes (coronary angiography: n = 16; computed tomography [CT] of either thorax or abdomen: n = 6; iodine dose range from 300-1221 mg of iodine per kilogram). Inclusion criteria were as follows: normal FT4, normal TSH, negative thyroid antibodies, urinary iodine excretion below 30 microg/dL, no palpable goiter and no euthyroid sick syndrome. All but one patient reacted with a TSH increase. Mean TSH values increased significantly 3-5 days after the iodine load within the normal range. Four patients (18%) had a TSH increase above normal, the maximal observed value being 6.4 microU/mL. Basal TSH values of these four patients were above 2 microU/mL. The day peak TSH concentrations were reached varied from day 1 to day 7, the majority (32%) having the peak on day 3. Peak TSH was significantly correlated with basal TSH values (r = 0.794, p < 0.0001). FT4 and FT3 remained unchanged and there was no significant correlation between the dose of iodine and the TSH reaction. In conclusion, iodine-containing contrast media can induce transiently subclinical hypothyroidism even in euthyroid patients. The TSH reaction seems to depend on the preexisting state of thyroid function.

Speciation studies by capillary electrophoresis -simultaneous determination of iodide and iodate in seawater

Abstract: A capillary electrophoresis (CE) method was developed for the simple and highly-sensitive determination of iodine species in seawater. The proposed method is based on the on-capillary preconcentration of iodide and iodate using the principle of transient isotachophoresis (tITP) stacking, and direct UV detection of the separated species at 226 and 210 nm, respectively. The preconcentration procedure takes advantage of the electrokinetic introduction of the terminating ion [2-(N-morpholino)ethanesulfonate (MES)] into the capillary, that enables a longer tITP state. The appropriate conditions for the tITP step were optimized by varying the MES and sample injection time and the concentration of cetyltrimethylammonium chloride (CTAC). The latter component of the separation electrolyte (SE) was shown to strongly affect the migration and therefore the enrichment of iodide due to specific ion-association. The optimized separations were performed in 12.5 mM CTAC, 0.5 M NaCl (pH 2.4). Valid calibration is demonstrated in the range 3–60 μg L−1 iodide (R=0.9992) and 40–800 μg L−1 iodate (R=0.9994). The detection limits achieved were 0.23 μg L−1 (2 nM) for iodide and 10 μg L−1 (57 nM) for iodate. Such sensitivity and linearity thresholds allowed the reported tITP-CE system to be applied to direct speciation analysis of surface and seabed seawater. The comparison of CE results with those of an ion-chromatography (IC) technique proved that the method has acceptable accuracy.

Metabolism of bromide and its interference with the metabolism of iodine.

Abstract: The present knowledge about the metabolism of bromide with respect to its goitrogenic effects, including some conclusions drawn from our recent research on this subject, is reviewed. Firstly, the biological behavior of bromide ion is compared with that of chloride and iodide. Secondly, the details about distribution and kinetics of bromide ions in the body and in 15 different organs and tissues of the rat are given. Significant correlation between the values of the steady-state concentration of bromide in the respective tissue and of the corresponding biological half-life was found in most tissues examined. A remarkably high concentration of radiobromide was found in the skin, which represents, due to its large mass, the most abundant depot of bromide in the body of the rat. Thirdly, the effects of excessive bromide on the rat thyroid are summarized, along with the interference of exogenous bromide with the whole-body metabolism of iodine. It is suggested that high levels of bromide in the organism of experimental animals can influence their iodine metabolism in two parallel ways: by a decrease in iodide accumulation in the thyroid and skin (and in the mammary glands in lactating dams), and by a rise in iodide excretion by kidneys. By accelerating the renal excretion of iodide, excessive bromide can also influence the pool of exchangeable iodide in the thyroid. Finally, our recent results concerning the influence of high bromide intake in the lactating rat dam on iodine and bromide transfer to the suckling, and the impact of seriously decreased iodine content and increased bromide concentration in mother's milk on the young are discussed. We must state, however, that the virtue of the toxic effects of excessive bromide on the thyroid gland and its interference with the biosynthesis of thyroid hormones, as well as the exact mechanism of bromide interference with postnatal developmental processes remains to be elucidated.

Coordinative interactions in a dye-sensitized solar cell

Abstract: Resonance Raman scattering studies of a complete dye-sensitized solar cell (DSC) including iodine and lithium iodide in the electrolyte indicate that triiodide (I3−) exchange the SCN− ligand of the ...

Iodine status remains critical in mother and infant in Central Anatolia (Kayseri) of Turkey.

Abstract: Severe iodine deficiency disorders have been eradicated in many parts of the world, but milder forms still exist and may escape detection. Turkey has long been known to be a mild to moderate iodine deficiency area. The aim of this study was to assess the iodine nutritional status and the thyroid function of pregnant women and their neonates in the region of Kayseri (central Anatolia of Turkey) that appeared to be iodine deficient in previous studies performed before the introduction of mandatory salt iodization. A cross-sectional voluntary screening study was performed in the Maternity Unit of a university hospital. A total of 70 mothers and their healthy full-term neonates were included in this study. Urinary iodine concentration was estimated in spot urine samples obtained from mothers and their neonates on day 5. All the neonates were breastfed. The iodine content was determined in the breast milk of all mothers on day 5. Serum concentrations of TSH, thyroglobulin (Tg), free triiodothyronine (FT3) and free thyroxine (FT4) were investigated in the cord serum of neonates and compared to those of mothers immediately after parturition The median urinary iodine on day 5 in mothers and their babies were 30.20 and 23.80 µg/l, respectively. These figures are much lower than normal for these age groups (150–200 µg/l). The median iodine content of breast-milk was 73 µg/l. It is again much lower than in iodine sufficient areas, indicating that the status of iodine nutrition of pregnant and lactating women is clearly insufficient. The median concentrations (and ranges) of neonatal TSH, Tg, FT3 and FT4 were 7.44 mU/l, 71.62 ng/ml, 1.30 pg/ml and 1.34 ng/dl respectively. The corresponding levels for the mothers during labor were 2.19 mU/l, 25.65 ng/ml, 1.31 pg/ml and 1.23 ng/dl respectively. The median neonatal serum concentrations of TSH and Tg were significantly higher than the corresponding maternal levels (P < 0.0001, P < 0.0001, respectively) and 27.1% of the neonates had serum TSH concentrations above 10 mU/l and 57.1 % had cord blood serum Tg concentrations above 54 ng/ml. None of the mothers showed TSH concentrations above 5 mU/l and 41.4% had serum Tg concentrations above 30 ng/ml. Iodine deficiency with low urinary iodine excretion and high serum Tg and TSH concentrations were recognized among pregnant women and their babies in Kayseri in spite of the program of salt iodization. National measures are urgently required for improving the correction of iodine deficiency in Turkey. This includes regular supplementation with iodine, starting at preconception or in early pregnancy and continuing during the period of nursing in this region.

Iodine as catalyst for the direct oxidation of methane to methyl sulfates in oleum

Abstract: A new series of iodine-containing compounds is reported as catalysts for the direct and selective oxidation of methane to methyl sulfates (especially mono methyl sulfate) in 65 wt.% oleum. The solubility of elemental iodine in 65 wt.% oleum at 180 °C was found to be ca. 34 mmol/l with only the dissolved part of the iodine as the active catalyst. A mathematical model for the relationship between the initial reaction rate and the iodine concentration is given. It is found that the iodine-catalyzed reaction is first order for methane (up to above 100 bar), but 0.5 order for iodine. Suitable reaction temperatures are in the range 170–190 °C. Besides elemental iodine, many compounds containing iodine, such as KI, NaI, CH3I, I2O5, KIO3 and KIO4, also catalyze the methane oxidation to methyl sulfates in oleum in the same manner and at the same iodine concentration indicating that they are converted into the same catalytic intermediate. High performance liquid chromatography and gas chromatography and other methods was used to clarify the stoichiometry of the proposed reaction schemes. Titration results showed that, when methane was in excess compared to the amount of SO3 in the beginning of an experiment, almost pure sulfuric acid (99.06±0.15%) was the result in the end of the experiment. Gas chromatograph measurements showed that 4.6% of the consumed methane was converted to CO2 while the overall selectivity of methane to methyl sulfates was found to be ca. 92%.

The elimination of iodine deficiency in the Czech Republic: the steps toward success.

Abstract: The Czech Republic has a long history of iodine deficiency. Salt iodization was introduced in 1947, followed by a progressive correction of iodine deficiency. The present study reports the changes in the status of iodine nutrition and of thyroid function in the country from 1994 to 2002. The study included 29612 individuals, aged 0 to 98 years, including 5263 individuals randomly selected from the general population and 24349 individuals who attended the Institute of Endocrinology of Prague (hospital population). Urinary iodine was determined in all individuals. Measurements of serum thyrotropin (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and thyroglobulin (Tg), were taken in 8544 to 19060 individuals. The iodine content of table salt was measured in 1130 samples. The median urinary iodine in the general and hospital populations were not significantly different. They progressively increased with time, starting from values indicating mild iodine deficiency (88-95 microg/L) prior to 1997, reaching the critical threshold of 100 microg/L in 1998, and optimal values between 120-140 microg/L since 2000. There was only a low and not significant positive correlation between the iodine content of salt and the urinary iodine. In contrast, urinary iodine showed marked seasonal changes, with the highest values during winter, when livestock were supplemented by mineral tablets containing iodine. Variables exploring thyroid function were all situated within the normal range in adults but another study (results not reported) has shown the persistence of slightly elevated TSH in neonates. The correction of iodine deficiency was not accompanied by unfavorable side effects. In conclusion, the Czech Republic has achieved sustainable elimination of iodine deficiency. Salt iodization has been a determining, but not the only, factor responsible for the success. Iodine supplementation of livestock and increased consumption of milk rich in iodine have probably played a determining role. Neonatal thyroid screening could constitute the major monitoring tool in order to insure sustainable elimination of iodine deficiency in the Czech Republic.

Fast and simple method for determination of iodide in human urine, serum, sea water, and cooking salt by capillary zone electrophoresis.

Abstract: 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 alpha-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 05 psi (345 kPa) into a fused-silica capillary (018 mm ID, 50 cm effective length) coated with polyacrylamide (electroosmotic flow < 2 x 10(-9) m(2)V(-1)s(-1)) and filled with the optimized background electrolyte composed of 20 mM KH(2)PO(4) and 07% 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 014 microM, for human serum 017 microM, for seawater 017 microM, and for cooking salt 89 nM Relative standard deviations of iodide peak area and height in all matrices ranged within 093 to 419%