Iodine

About: Iodine is a research topic. Over the lifetime, 8936 publications have been published within this topic receiving 139981 citations. The topic is also known as: I & element 53.

A new method for the measurement of thyroidal iodine release in man

Abstract: A new method is described for the detection of variations in the release rate of all iodinated products by the thyroid gland in man. (125)I was employed to endogenously label the thyroid gland, and a parenterally administered (131)I thyroxine dose was used to generate a (131)I reference source. Thyroidal iodine release activity was quantitatively assessed by the measurement of variations in (125)I/(131)I ratio values obtained in timed urine samples. Diurnal variation in thyroid release patterns was observed in euthyroid subjects which was promptly suppressed by exogenous triiodothyronine administration and was simulated by the intramuscular injection of 0.25-0.50 U of bovine thyrotropin. The zenith value occurred at 4:00 a.m. +/-3.4 hr (SD) and the nadir at 5:00 p.m. +/-3.6 hr. The absence of a diurnal pattern in patients with thyrotoxicosis and in secondary hypothyroidism indicated that this diurnal fluctuation was under thyrotropin (TSH) regulation. This new method also promises to be a useful tool for the study of the intrathyroidal recycling of iodide from the iodotyrosine pool and the detection of factors which may acutely alter thyroid function.

Iodine and bromine speciation in snow and the effect of orographically induced precipitation

Abstract: Iodine is an essential trace element for all mam- mals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the ter- restrial environment, the processes effecting its distribution, speciation and transport are relatively unknown. The aim of this study was to determine the effect of orographically induced precipitation on iodine concentrations in snow and also to quantify the inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile ( 840 m) from the northern Black Forest and were analysed by ion-chromatography - inductively coupled plasma mass spectrometry (IC-ICP-MS) for iodine and bromine species and trace metals (ICP-MS). All elements and species concen- trations in snow showed significant ( r 2 >0.65) exponential decrease relationships with altitude despite the short (5 km) horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l) over the 840 m height change. The results suggest that orographic lifting and subsequent precipitation has a major influence on iodine concentrations in snow. This orographically induced removal effect may be more important than lateral distance from the ocean in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all ele- ments indicating that the iodine and bromine are internally mixed within the snow crystals. We also show that organ- ically bound iodine is the dominant iodine species in snow (61-75%), followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two un- known but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2- 10% of the total iodine. The majority of the bromine was inorganic bromide with a max. of 32% organo-Br.

Ten-year follow-up of thyroid epidemiology in Slovenia after increase in salt iodization.

Abstract: Iodine is an essential element of thyroid hormones, crucial for the prevention of iodine deficiency disorders. Iodine supplementation is an important public health measure that influences the thyroid volume and determines the epidemiology of thyroid disorders. According to the World Health Organization (WHO) criteria, the main indicators of iodine supply are median urinary iodine concentration (UIC) and thyroid size in schoolchildren (1). There are limited and sometimes conflicting longitudinal studies on epidemiology of thyroid disorders after the increase in iodine intake in areas with previously mild iodine deficiency. A few studies reported an early increase in the incidence of hyperthyroidism due to Graves’ disease and thyroid autonomy (2-4), in some cases followed by a decrease (2,5). Some reported an increased incidence of hypothyroidism (5), probably due to a higher incidence of thyroid autoimmunity (6-8). All investigators observed a decrease in the incidence of diffuse goiter in young population (3,9-11), while the data in the elderly are controversial (3,12). The prevalence of goiter in Slovenia between the two world wars was up to 80% (13). In 1953, iodine prophylaxis was introduced with addition of 10 mg potassium iodide per kilogram of kitchen salt. In 1991 to 1994, an epidemiological study revealed a goiter grade 2 by WHO criteria in 11% of 1740 schoolchildren aged 13 years (14). The mean thyroid volume measured by ultrasonography was 7.2 mL and UIC was lower than 100 μg/g of creatinine in 73.7% of children, with a median of 82.9 μg/g of creatinine (14), which classified Slovenia a mildly iodine-deficient according to the WHO criteria. Therefore, in January 1999 the Ministry of Health issued a recommendation for mandatory salt iodization with 25 mg (within range of 20-30 mg) of potassium iodide. In this study, we investigated the iodine supply and incidence of different thyroid disorders in Slovenia after the increase in salt iodization in 1999. We assessed the iodine supply in a population of schoolchildren using UIC and measurement of thyroid volume. We also performed a ten-year follow-up on the incidence of different thyroid disorders, including goiter, thyroid autonomy, Graves’ disease, and Hashimoto’s thyroiditis in the adult population.

Recovery of gold and/or palladium from an iodide-iodine etching solution

Abstract: A method of recovering gold and palladium from a spent aqueous potassium iodide-iodine etching solution, and regenerating the etching solution for reuse, involves adjusting the spent solution to a strongly basic pH (e.g., 12.5) by the addition of an alkaline compound (e.g., potassium hydroxide) to precipitate metallic gold from the solution. Metallic palladium is precipitated from the resulting alkaline solution by the addition of a borohydride, (e.g., potassium borohydride). Following removal of the precipitated gold and palladium, the spent alkaline solution is made acidic-to-neutral in pH to change potassium hypoiodite and some potassium iodide in the solution to iodine. The solution then is adjusted back upward to a slightly alkaline pH value (e.g., 9.0), and precipitate is removed at room temperature. Potassium iodide and iodine crystals then are added to the solution, as necessary, to regenerate the solution to substantially its original composition and strength for reuse.