Chlorine total

This is an indirect method of analysis because the chlorine-containing species do not react with the titrant. Instead the total chlorine residual oxidizes l to l3 , and the amount of 13 is determined by the redox titration with Na282 03. 

One of the most important applications of redox titrimetry is in evaluating the chlorination of public water supplies. In Method 9.3 an approach for determining the total chlorine residual was described in which the oxidizing power of chlorine is used to oxidize R to 13 . The amount of 13 formed is determined by a back titration with 8203 . 

Year Vinyl chloride monomer b, r Isocyanates Fluorocarbons c C2 Other Total Chlorine and hydrogen Salt and sulfuric acid Total... 

An integrated process for producing chlorine dioxide that can consume chlorine (46) involves the use of hydrochloric acid as the reductant. The spent chlorine dioxide generator Hquor is used as feed for chlorate production, and hydrogen gas from chlorate production is burned with chlorine to produce hydrochloric acid. The principal disadvantage in the integrated hydrochloric acid-based processes is that the chlorine dioxide gas contains Y2 mole of chlorine for each mole of chlorine dioxide produced. A partial purification is achieved by absorption in chilled water in which the solubiHty of chlorine is less than chlorine dioxide however, this product stiU contains 10—15% chlorine on the basis of total chlorine and chlorine dioxide. 

The side-chain chlorine contents of benzyl chloride, benzal chloride, and benzotrichlorides are determined by hydrolysis with methanolic sodium hydroxide followed by titration with silver nitrate. Total chlorine determination, including ring chlorine, is made by standard combustion methods (55). Several procedures for the gas chromatographic analysis of chlorotoluene mixtures have been described (56,57). Proton and nuclear magnetic resonance shifts, characteristic iafrared absorption bands, and principal mass spectral peaks have been summarized including sources of reference spectra (58). Procedures for measuring trace benzyl chloride ia air (59) and ia water (60) have been described. 

The (9-cresol novolaks of commercial significance possess degrees of polymerization, n, of 1.7—4.4 and the epoxide functionaUty of the resultant glycidylated resins varies from 2.7 to 5.4. Softening points (Durran s) of the products are 35—99°C. The glycidylated phenol and o-cresol—novolak resins are soluble in ketones, 2-ethoxyethyl acetate, and toluene solvents. The commercial epoxy novolak products possess a residual hydrolyzable chlorine content of <0.15 wt% and a total chlorine content of ca 0.6 wt % (Table 2). 

The bound chloiine formed does not readily saponify with metal hydroxide solutions and is analyzed as part of the total chlorine of the resin. (3) Incomplete dehydrohalogenation which results in residual saponifiable or hydrolyzable chlorine ... 

Chlorine makes up 50% or more of the weight of all the chlorinated hydrocarbons under consideration except methoxychlor, which contains 30%. Therefore, methods based on the determination of total chlorine appear appropriate. Such methods are not specific, however, and any other chlorine-containing organic compound will interfere. 

In one procedure that has been widely used, the sample, after suitable treatment, is refluxed with sodium and isopropyl alcohol, after which the solution is diluted with water and the inorganic chloride is determined by standard methods (13, 54) The method has been adopted by the Association of Official Agricultural Chemists 29, 30) as a tentative one for technical DDT and for dusts, oil solutions, and aqueous emulsions of DDT, for use in the absence of other chlorine-containing compounds. The National Association of Insecticide and Disinfectant Manufacturers has also accepted the total-chlorine method for the analysis of these preparations 28). Essentially the same procedures have been described by Donovan 22), of the Insecticide Division of the Production and Marketing Administration, for technical DDT and various commercial DDT products containing no other compounds interfering with the chlorine determination. 

Carter 12), of the Bureau of Entomology and Plant Quarantine, has adapted the total-chlorine method to the analysis of mixtures of DDT and benzene hexachloride in the following manner After determination of total chlorine in the mixture, the DDT is estimated by the Schechter-Haller colorimetric method 47), half this value is subtracted from the total chlorine (because DDT contains 50% of chlorine), and the difference is calculated as benzene hexachloride. This procedure gives no indication of the amount of the gamma isomer of benzene hexachloride. 

The total-chlorine method has been used extensively in the determination of spray residues of the chlorinated hydrocarbons 56). Usually the kind of insecticide applied has been known, and by means of the proper factor the chlorine values could be calculated to the insecticide originally used. This calculation is not entirely valid, as the determinations do not differentiate between the insecticide and its degradation products or other contaminants containing organic chlorine. The values obtained by the total-chlorine method are useful, however, because they indicate the magnitude of the residue and the analysis can be made in a short time with standard laboratory equipment. 

The total-chlorine method for determining residues of benzene hexachloride, chlordan, and toxaphene has also been used 55) in experiments where it was known that these insecticides had been applied. With benzene hexachloride, which is known to give off-flavor to some crops, it has not been demonstrated that a relation between organic chlorine values and off-flavor exists. In fact, in most cases where off-flavor was attributed to benzene hexachloride, it has not been possible to detect organically bound chlorine. 

The total-chlorine method for residues of the chlorinated hydrocarbons has also been applied to animal tissues, milk, and dairy products (9). As in the spray-residue determinations, the method does not differentiate between the insecticide and metabolites. 

Recently it was shown that when DDT, benzene hexachloride, or toxaphene is fed or applied to cattle, such organic chlorine residue as may be present in the fatty tissues consists essentially of unchanged insecticide. Carter (12) demonstrated their presence by separating the fats and other oxygenated products with sulfuric acid-sodium sulfate mixture and determining total chlorine. In experiments with DDT Schechter (46) demonstrated its presence in fatty tissue and in butterfat by the Schechter-Haller colorimetric method (47). The residues were then tested for toxicity to houseflies in comparison with the known insecticides of the same concentration. In both cases the known insecticide gave the same mortality as the residue. 

Parathion analyses were made by the method of Averell and Norris (I). DDT residues were determined at Vincennes by the total-chlorine method of Wichman et al. (4), and at Yakima by the colorimetric method of Stiff and Castillo (3), as modified by the Food and Drug Administration (2). 

BHC in each technical BHC sample determined by partition chromatography. b The common name for the 7-isomer of benzene hexachloride of a purity of not less than 99%. c Calculated from total chlorine determination on DDT fraction. 

Emissions from hazardous waste combustors are regulated under two statutory authorities RCRA and the CAA. The MACT standards set emission limitations for dioxins, furans, metals, particulate matter, total chlorine, hydrocarbons/carbon monoxide, and destruction and removal efficiency (DRE) for organics. Once a facility has demonstrated compliance with the MACT standards by conducting its comprehensive performance test (CPT) and submitting its notification of compliance (NOC), it is no longer subject to the RCRA emission requirements with a few exceptions. RCRA-permitted facilities, however, must continue to comply with their permitted emissions requirements until they obtain modifications to remove any duplicative emissions conditions from their RCRA... 

Boilers and most industrial furnaces must follow a tiered system for the regulation of both hydrogen chloride and chlorine gas. The owner and operator determine the allowable feed or emission rate of total chlorine by selecting one of three approaches, called tiers. Each tier differs in the amount of monitoring, and in some cases, air dispersion modeling (i.e., modeling the air pathways through which pollutants may travel) that the owner and operator are required to conduct. 

Rather than a tiered system to control hydrogen chloride and chlorine gas emissions, MACT combustion units must meet numerical emission limits for total chlorine. Owners and operators of these units must ensure that the total chlorine emission does not exceed specific limits, expressed in ppmv. For example, the allowable limit of total chlorine for a new incinerator is 21 ppmv. The owner or operator may choose to achieve this level by controlling the amount of chlorine entering the incinerator. By achieving the regulatory emission limit of chlorine, both hydrogen chloride and chlorine gas emissions will be reduced. 

Chemical pulp bleaching has undergone significant process changes since around 1990. Until that time, nearly every chemical pulp mill that had used bleaching had incorporated elemental chlorine (Clj) into some of its processes. Because of environmental and health concerns about dioxins, U.S. pulp mills now use elemental chlorine free (ECF) and total chlorine free (TCF) bleaching technologies. The most common types of ECF and TCF are shown in Table 21.5. The difference... 

Common Chemicals Used in Elemental Chlorine Free (ECF) and Total Chlorine Free (TCF) Bleaching Processes... 

Elemental chlorine free (ECF) bleaching with low AOX or totally chlorine free (TCF) bleaching... 

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