Lodometric titration

Test Method for Sulfur in Graphite by Combustion—lodometric Titration Method... 

Determination. The most accurate (68) method for the deterrnination of copper in its compounds is by electrogravimetry from a sulfuric and nitric acid solution (45). Pure copper compounds can be readily titrated using ethylene diamine tetracetic acid (EDTA) to a SNAZOXS or Murexide endpoint. lodometric titration using sodium thiosulfate to a starch—iodide endpoint is one of the most common methods used industrially. This latter titration is quicker than electrolysis, almost as accurate, and much more tolerant of impurities than is the titration with EDTA. Gravimetry as the thiocyanate has also been used (68). 

Water Transfer 5 mL acetic acid, or enough to adjust sample pH between 3 and 4, and 1 g Kl, and 1 ml starch solution pour in sample and mix. lodometric titration 20 ig/L No data APHA 1998 (Method 4500-CL02-B)... 

Diphenylbenzo[c]furan is reportedly attacked by oxygen without catalysts in the dark, even in the solid state. When a solution of 138 in benzene (or toluene) is treated with oxygen, on precipitation with ether a white powder with mp 140°C is obtained in 82% yield on heating to 150— 170°C explosion occurs/ lodometric titration in tetrahydrofuran showed a content of 94% peroxide from this solution 37% o-dibenzoylbenzene (140) has been obtained. The molecular weight was determined to be 2830 (cryoscopic in benzene) and th6 structure formulated as 241 ( = 8-10). 

The total concentration or amount of chlonne-based oxidants is often expressed as available chorine, or less frequently as active chlorine. Available chlorine is the equivalent concentration or amount of Q2 needed to make the oxidant according to equations 1-4. Active chlorine is the equivalent coiicentiation oi amount of Cl atoms that can accept two electrons. This is a convention, not a description of the reaction mechanism of the oxidant. Because Cl2 only accepts two electrons as does HOCI and raonochloramines, it only has one active Cl atom according to the definition. Thus the active chlorine is always one-half of the available chlorine. The available chlorine is usually measured by lodometric titration. Tlie weight of available chlorine can also be calculated by equation 5. where 70.9 represents the mol wt of Cl2 and moles of oxidant can be represented wt oxidant/mol wt of oxidant. 

Basic Protocol 2 Determination of Peroxide Value by lodometric Titration D2.1.4... 

Iodine, colorimetric determination of amylase using, 689-692 Iodine value, lipid composition canola oil, 474 (table) oil quality indices, 467-469, 475-477 lodometric titration, determination of peroxide value, 518-519 Ionization techniques, in mass... 

Traditional techniques to measure dissolved sulfur in marine porewaters are iodometric titrations and colorimetric methods based on methylene blue color development. However, these methods(17-] ) are not capable of measuring a wide variety of sulfur species or distinguishing between sulfur species. Major sulfur species are defined as those with concentrations typically greater than 10 uM. lodometric titrations can determine sulfur in -1 and -2 oxidation states as shown in equations (1) through (4). However, these titrations cannot distinguish between all of the various forms. 

After all the peracetic acid has been added, the reaction mixture is diluted with 80 ml. of water and heated from 35° to 100° over a 20-minute period (Note 2). It is then kept at 100° for 45 minutes. The flask is cooled to 0-5° in an ice bath, and the solid iodoxybenzene is collected on a Buchner funnel and air-dried with suction for 1 hour. Additional material is obtained by concentrating the filtrate to one-fourth of its volume Caution Note 3). The two crops of crude iodoxybenzene are combined and dried overnight in a desiccator weight 19.6-20.5 g. m.p. 230° Caution Explodes ). lodometric titration shows the purity to be about 94% (Note 4). 

For polluted waters or chlorinated waste waters where residual chlorine is present mainly in the combined form, analytical methods do not need to distinguish between FAC and combined available chlorine. lodometric titration is not recommended because these water samples typically contain small amoimts of reducing agents that can react with, and thereby reduce, the liberated iodine over the course of the titration. In this case, an iodimetric procedme is recommended. Arsenic(III) (as arsenic trioxide, AS2O3) is added to the sample in a known amount that is in excess of the combined chlorine, and unreacted As(III) is titrated with a standard solution of I3" to a starch endpoint (formation of a blue color). 

Since the 1960s new techniques such as AAS, ICP-AES, and XRF have been used for plant control and environmental measurements. lodometric titrations are still used in many industrial laboratories, but the newer methods are more rapid and convenient. Other techniques including colorimetry, electrodeposition. 

Table 16-3 lodometric titrations Titrations of iodine (actually I3) produced by analyte... 

COLOR PLATE 12 lodometric Titration (Section 16-3) Left Initial I5 solution. 

Analysis of Reagent Purity H NMR analysis of iminoiodane purity is unreliable since it is unstable and only slightly soluble in CDCI3. lodometric titration is possible. Another test of purity could be the use of the reagent in a standard aziridination applied to a five-molar excess of styrene. ... 

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