Iodate separation

H. Klinger made the di-iodate by mixing 20 grms. of potassium chlorate, 21 grms. of iodine, and 100 c.c. of water in a half-litre tubulated retort with a thermometer fitted in the tubulure, and the neck directed upwards. The mixture is heated by a small flame. The liquid becomes yellow, and violet vapours condense in the neck of the retort. The materials begin to react at about 85°, and the reaction is complete at about 95°. Only a little chlorine is evolved when the liquid is heated up to its b.p. When the colourless liquid is cooled, crystals of the di-iodate separate, and these can be purified by recrystallization from hot water. The yield is over 70 per cent. Some barium di-iodate can be recovered by adding barium chloride to the mother-liquid. 

When Po ion in nitric acid is treated with HIO3, white crystals of the iodate separate. The crystals decompose at 350 400 °C, but a satisfactory analysis has not been obtained for this material. 

Iodic acid can also be obtained by tlie action of dilute sol-pbndo acid on barinm iodate, which is prepared as follows the requisite quantity of iodine is dissolved in a bob concentrated sdn-tion of potassium chlorate and a few drops of nitric add added immediatdy a vblent evolution of cUtnine gas commences, and,bn oooU)qg, the potassium iodate crystalHzes out This salt is then dissolved in water and to the edution barium-ddoride is added, when barium iodate separates out as a white powder. 

Approximately 80 wt % of the potassium iodate [7758-05-6] KIO, crystallizes from the reaction mixture and is separated for sale. Of the remainder, 90 wt % is removed by evaporation, fusion, and heating to ca 600°C. 

A mixture of dimethyl sulfate with SO is probably dimethyl pyrosulfate [10506-59-9] CH2OSO2OSO2OCH2, and, with chlorobenzene, it yields the 4,4 -dichlorodiphenylsulfone (153). Trivalent rare earths can be separated by a slow release of acid into a solution of rare earth chelated with an ethylenediaminetetraacetic acid agent and iodate anion. As dimethyl sulfate slowly hydrolyzes and pH decreases, each metal is released from the chelate in turn and precipitates as the iodate, resulting in improved separations (154). 

Oxo Ion Salts. Salts of 0x0 anions, such as nitrate, sulfate, perchlorate, iodate, hydroxide, carbonate, phosphate, oxalate, etc, are important for the separation and reprocessing of uranium, hydroxide, carbonate, and phosphate ions are important for the chemical behavior of uranium ia the environment (150—153). 

Preparation ofpure potassium hydrogeniodate. Dissolve 27 g of potassium iodate in 125 mL of boiling water, and add a solution of 22 g of iodic acid in 45 mL of warm water acidified with six drops of concentrated hydrochloric acid. Potassium hydrogeniodate separates on cooling. Filter on a sintered-glass funnel, and wash with cold water. Recrystallise three times from hot water use 3 parts of water for 1 part of the salt and stir continuously during each cooling. Dry the crystals at 100 °C for several hours. The purity exceeds 99.95 per cent. 

Procedure. Acidify the iodate solution (lOOmL containing ca 0.3 g of I03) (see Note) with sulphuric acid, and pass in sulphur dioxide (or add a freshly prepared saturated solution of sulphurous acid) until the solution, which at first becomes yellow, on account of the separation of iodine, is again colourless. Boil off the excess of sulphur dioxide, and precipitate the iodide with dilute silver nitrate solution as described in Section 11.64. Weigh as Agl. 

Iodine was determined by an iodometric titration adapted from White and Secor.(3) Instead of the normal Carius combustion, iodide was separated from the samples either by slurrying in 6M NaOH, or by stirring the sample with liquid sodium-potassium (NaK) alloy, followed by dissolving excess NaK in ethanol. Precipitated plutonium hydroxides were filtered. Iodine was determined in the filtrate by bromine oxidation to iodate in an acetate buffer solution, destruction of the excess bromine with formic acid, acidifying with SO, addition of excess KI solution, and titrating the liberated iodine with standard sodium thiosulfate. The precision of the iodine determination is estimated to be about 5% of the measured value, principally due to incomplete extraction of iodine from the sample. 

In the process of separating Pb2 ions from Cu2+ ions as sparingly soluble iodates, what is the Pb2+ concentration when Cu2+ just begins to precipitate as sodium iodate is added to a solution that is initially 0.0010 m Pb(N03)2(aq) and 0.0010 M Cu(N03)2(aq) ... 

Procedure Weigh accurately benzalkonium chloride 4.0 g and dissolve it in sufficient DW to make 100 ml. Pipette 25.0 ml into a separating funnel, add 25 ml of chloroform, 10 ml of 0.1 N NaOH and 10 ml of potassium iodide solution. Shake the contents thoroughly, allow to separate and collect the chloroform layer in another separating funnel. Treat the aqueous layer with 3 further quantities each of 10 ml of chloroform and discard the chloroform layer. To the aqueous layer add 40 ml of hydrochloric acid, cool and titrate with 0.05 M potassium iodate till the solution becomes pale brown in colour. Add 2 ml of chloroform and continue the titration until the chlorofonn layer becomes colourless. Titrate a mixture of 29 ml of water, 10 ml of KI solution and 40 ml of hydrochloric acid with 0.05 M potassium iodate under identical conditions (Blank Titration). The differences between the titrations represent the amount of 0.05 M potassium iodate required. Each ml of 0.05 M potassium iodate is equivalent to 0.0354 g of C H CIN. 

Stathakis and Cassidy, on his part, used a-, y- (0—40mM/L), or -cyclodextrin (0—lOmM/L) to separate a mix containing iodide, nitrate, perchlorate, thiocyanate, bromate, iodate, ethanesulfonate, pentanesulfonate, and octanesulfonate. The separation of nitrate and nitrite can be improved by the addition of 3% a-cyclodextrin in a 30mM PDC buffer at pH 5.4 (Figure 15). 

Chilean saltpeter [potassium nitrate (KNOj)] has a number of impurities, including sodium and calcium iodate. Iodine is separated from the impurities and, after being treated chemically, finally produces diatomic iodine. Today, iodine is mostly recovered from sodium iodate (NalO ) and sodium periodate (NalO ) obtained from Chile and Bohvia. 

A few DBFs, such as bromate, chlorate, iodate, and chlorite, are present as anions in drinking water. As a result, they are not volatile and cannot be analyzed by GC/MS. They are also difficult to separate by LC, but will separate nicely using ion chromatography (IC). At neutral pH, HAAs are also anions and can be separated using 1C. A number of methods have been created for these DBFs using both IC/ inductively coupled plasma (ICF)-MS and IC/ESl-MS. Fretreatment to remove interfering ions (e.g., sulfate and chloride), along with the use of a suppressor column prior to introduction into the MS interface, is beneficial for trace-level measurement. 

Most potassium iodate, KIO3, is separated from the product mixture by crystallization and filtration. Remaining iodates are removed by evaporation of the solution and other processes, such as carbon reduction or thermal decompostion at 600°C to iodide ... 

Torimura etal. [194] developed an analytical approach capable of determining subnanomolar amounts of carbohydrates based on the indirect detection of iodate, 103 , at a glassy carbon electrode. The method was applied as a postcolumn detection system for HPLC separation. 

Formerly all the iodine was made from the ash of seaweed, and potash was a remunerative appendix to the iodine industry but just as the Stassfurt salts killed those industries which extracted potash from other sources, so did the separation of iodine from the caliche mother-liquors threaten the industrial extraction of iodine from seaweed with extinction. Iodine in a very crude form was exported from Chili in 1874—e.g. a sample was reported with iodine 52-5 per cent. iodine chloride, 3-3 sodium iodate, 13 potassium and sodium nitrate and sulphate, 15 9 magnesium chloride, 0 4 insoluble matter, 1 5 water, 25-2 per cent. About that time much of the iodine was imported as cuprous iodide. This rendered necessary the purification of the Chilian product but now the iodine is purified in Chili before it is exported. The capacity of the Chilian nitre works for the extraction of iodine is greater than the world s demand. It is said that the existing Chilian factories could produce about 5100 tons of iodine per annum whereas the... 

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