Iodides in milk

Iodide ion-selective electrode The iodide electrode has broad application both in the direct determination of iodide ions present in various media as well as for the determination of iodide in various compounds. It is, for example, important in the determination of iodide in milk [44,64,218, 382, 442], This electrode responds to Hg ions [150, 306, 439] and can be used for the indirect determination of oxidizing agents that react with iodide, such as 10 [305], lOi [158], Pd(II) [117, 347,405] and for the determination of the overall oxidant content, for example in the atmosphere [393], It can also be used to monitor the iodide concentration formed during the reactions of iodide with hydrogen peroxide or perborate, catalyzed by molybdenum, tungsten or vanadium ions, permitting determination of traces of these metals [12,192,193, 194, 195]. The permeability of bilayer lipid membranes for iodide can be measured using an I"... 

Lacroix, D. E. and Wong, N. P. 1980. Determination of iodide in milk using the iodide specific ion electrode and its application to market milk samples. J. Food Protection 43, 672-674. 

The determination of iodide in milk (2% milkfat) by ion chromatography coupled with pulsed amperometric detection on a silver electrode is an application that benefits from matrix elimination of fats. The pulsed amperometric waveform improves reproducibility by electrochemically cleaning the working electrode on each pulse. In addition, the fats are removed from the sample using a disposable cartridge containing a polymeric reversed phase resin (OnGuard II RP, Dionex Corp.). When 50 jal of 0.1 mg/1 iodide was added to 200 jal of prepared milk, the recovery was 100%. The iodide peak area and retention time RSDs were 1.4% and 0.4% respectively [28]. 

P. Bermejo Barrera, M. Aboal Somoza, A. Bermejo Barrera, M. L. Cervera, M. de la Guardia, Microwave assisted distillation of iodine for the indirect atomic absorption spectrometric determination of iodide in milk samples, J. Anal. Atom. Spectrom., 16 (2001), 382-389. 

Various forms of iodine are convertible into iodoacetone, which was extracted with hexaneFor the detection of iodide in milk, proteins were precipitated with diluted sulfuric acid, and the filtrate was treated with acetone and potassium iodate. For total iodine a digestion with potassium carbonate was carried out at 600° Elemental phosphorus is extracted into benzene or isooctane from water, aqueous filtered extractions of mud or homogenized tissue-filtered extracts ... 

For health purposes, the determination of inorganic anions such as nitrite, nitrate, and iodide in milk and milk products [345,346] is of great importance. Together with secondary amines, nitrite, for example, can form carcinogenic nitrosamines an excess of iodide can provoke thyroid malfunction. To prolong... 

Figure 10.248 Determination of iodide in milk- and soy-based infant formuias. Separator column lonPac AS11 column dimensions ...

Metrohm AG, Metrohm Application Note S-162 Iodide in Milk Powder. Metrohm AG, Herisau, Switzerland. 

Breast milk During lactation human mammary tissue expresses the sodium iodide symporter [260], and thus significant transfer of perchlorate into human milk is likely. The presence of micrograms per liter concentrations of perchlorate in milk collected fi om US women [233] confirms lactation as a relevant perchlorate excretion path. If lactating women are secreting perchlorate in milk, then urine-based estimates of total perchlorate exposure for these individuals are likely to be lower than actual [242]. 

Kirk AB, Martinelango PK, Tian K, Dutta A, Smith EE, Dasgupta PK (2005) Perchlorate and iodide in dairy and breast milk. Environ Sci Technol 39 2011-2017... 

Some methods which do not involve separation of the FFAs from the milk fat or the whole product have considerable appeal because of their simplicity. Sharma and Bindal (1987) exploited the property of methyl urea to complex triglycerides in producing methyl esters with BF3-methanol without first separating the FFAs from the fat, while Spangelo et al. (1986) were able to methylate FFAs in an acetonitrile extract of milk with methyl iodide in the presence of an anion exchange resin as catalyst. Miwa and Yamamoto (1990) derivatised the FFAs in milk and milk products for HPLC analysis by direct reaction with 2-nitrophenylhydrazine hydrochloride. 

Other methods were developed for various anions. Bromides were oxidized with permanganate and the bromine so produced reacted with cyclohexene to form 1,2-dibromocyclohexane [577]. Similarly, iodides were analysed in milk as monoiodoacetone after oxidation with iodate and after reaction of the released iodine with acetone [578]. Pennington [579] utilized the same oxidation reaction for the analysis of iodates the iodine released was analysed as such. Cyanides were chlorinated prior to analysis with chloramine-T and the cyanogen chloride so produced was subjected to GC [580]. Analogously, cyanides and isocyanates form cyanogen bromide with bromine water, which can be analysed by GC [581]. 

Grys [654] studied this method in more detail and applied it to the determination of iodine, present as a free element, iodide and firmly bound iodine in milk. A 0.4-ml volume of fresh milk was placed in a 35-ml Kjehldahl swan-necked flask, mixed with 1.0 ml of 2 M potassium carbonate solution, dried at 105°C overnight and then ashed at 600—... 

Grys, S. The gas-liquid chromatographic determination of inorganic iodine, iodide and tightly bound iodine in milk. J. Chromatogr. 100, 43 (1974)... 

Milk products Determination of iodide in whole milk chloride and/or sodium in butter lactate, pyruvate and citrate in cheese... 

Iodide was identified as the main iodine species in milk, but in a few samples also traces of iodate and several unidentified, presumably organoiodine, compounds were observed. 

Let us consider the determination of iodides as an example. The reaction method of iodide determination was proposed by Hasty [137, 138]. It is based on iodination of ketones in an acidic medium followed by determination of the resulting iodoketone by gas-liquid chromatography using an electron-capture detector. The method was later improved by using butanone-2 instead of acetone, which made it possible to increase the detection sensitivity [139]. A similar method for determining the total content of inorganic iodine in milk was proposed by Bakker [140]. The detection limit does not exceed lOmg/1. It is a sufficiently accurate method with a relative standard deviation of 1.9%. 

In milk and urine, most iodine occurs as iodide, but are some species of organic iodine also found. The iodine species in fish are similar to that in the human body. 

Thiocyanate is a competitive inhibitor of the sodium iodide transporter responsible for the accumulation of iodide in the thyroid gland and in breast milk. 

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