Chlorinated hydrocarbons, determination

Several effects such as chloracne and alterations in hepatic metabolism have been associated with exposure to 2,3,7,8-TCDD in humans. However, these effects are not specific for 2,3,7,8-TCDD or other CDDs, but may be induced by numerous other chlorinated hydrocarbons. Determination of specific biomarkers of effect for CDD and development of reliable methods to quantify these effects would be useful in assessing the effects associated with exposure to CDDs. 

Chlorinated hydrocarbons, determination of 244 Chlorinated polyaromatic hydrocarbons, determination of 132 Chlorinated insecticides,... 

Pesticides. Chlorinated hydrocarbon pesticides (qv) are often found in feed or water consumed by cows (19,20) subsequently, they may appear in the milk, where they are not permitted. Tests for pesticides are seldom carried out in the dairy plant, but are most often done in regulatory or private specialized laboratories. Examining milk for insecticide residues involves extraction of fat, because the insecticide is contained in the fat, partitioning with acetonitrile, cleanup (FlorisH [26686-77-1] column) and concentration, saponification if necessary, and determination by means of paper, thin-layer, microcoulometric gas, or electron capture gas chromatography (see Trace and residue analysis). 

In Figure 3-6 are plotted the k values (ordinates) for various chlorinated hydrocarbon polymers, the chlorine contents as determined analytically after fusion with sodium peroxide being the abscissas. The x-ray results were obtained in about one tenth the time required for the conventional analyses. The experimental points lie close to the solid line in Figure 3-6. The deviations from the solid line may be due to any one or any combination of the following causes. 

Chlorine, determination by x-ray emission spectrography, 328 in chlorinated hydrocarbon polymers, determination by x-ray absorptiometry, 79-82... 

Electrochemical promotion has also been used to determine the optimal alkali promoter coverage on Ag epoxidation catalysts as a function of chlorinated hydrocarbon moderator level in the gas phase (Chapter 8). 

Sediment pollution. The concentrations of pollutants in the dated sediment cores have been determined in our laboratory by atomic absorption spectrophotometry (AAS). Donazzolo et al. (15) and Pavoni et al. (16) reported mainly heavy metal concentrations. Marcomini et al. (17) and Pavoni et al. (18) discussed the concentration profiles of organic pollutants such as chlorinated hydrocarbons and polycyclic aromatic hydrocarbons. 

Dietz EA Jr, Singley KF. 1979. Determination of chlorinated hydrocarbons in water by headspace gas chromatography. Anal Chem 51 1809-1814. 

R. Tauler, A.K. Smilde, J.M. Henshaw, L.W. Burgess and B.R. Kowalski, Multicomponent determination of chlorinated hydrocarbons using a reaction-based chemical sensor. 2 Chemical speciation using multivariate curve resolution. Anal. Chem., 66 (1994) 3337-3344. 

The methods of analysis for the chlorinated hydrocarbons may be divided into five classes—determination of total organic chlorine, determination of hydrolyzable or labile chlorine, colorimetric methods, physical methods, and bioassays. The last mentioned is beyond the scope of this manuscript and is not considered. 

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. 

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 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. 

More experimental work has been done with DDT than with all the other five chlorinated hydrocarbons combined, probably because DDT was the first of the group found to have insecticidal value. Carter (10) has summarized the several colorimetric methods for DDT. The one proposed by Stiff and Castillo (51), as modified by Claborn (14), and the one by Schechter and Haller (47) have probably been most widely used. In the Stiff and Castillo method, when the DDT is heated in pyridine solution containing xanthydrol and potassium hydroxide, a red color develops which is proportional to the quantity of DDT present. The reaction is sensitive to 10 micrograms. As TDE does not give a color with this reagent, Claborn (14) has proposed the reaction for the determination of DDT in the presence of TDE. He has also shown that for the development of the color the amount of water in the pyridine is critical. 

Methods utilizing characteristic physical properties have been developed for several chlorinated hydrocarbon insecticides. Daasch (18) has used infrared spectroscopy for the analysis of benzene hexachloride. By this means it is possible to determine the gamma-isomer content, as well as that of the other isomers of technical benzene hexachloride, provided the product is substantially free of the higher chlorinated cyclohexanes. 

Cristol et al. (17) have based a method for the determination of p,p -DDT in technical DDT on the fact that the p,pf isomer is almost insoluble in 70% aqueous ethyl alcohol and the o,p isomer is soluble. The method has not been tried with mixtures of the other chlorinated hydrocarbons. 

Tauler R., Smilde A.K., Hemshaw J.M., Burgess L.W., Kowalski B.R., Multicomponent Determination of Chlorinated Hydrocarbons Using a Reaction-based Chemical Sensor. Part 2. Chemical Speciation Using Multivariate Curve Resolution, Anal. Chem. 1994 66 3337-3344. 

A variety of compounds have been evaluated for developmental immunotoxicity. Early work with chlorinated hydrocarbon insecticides revealed that lactating women exposed to the insecticide chlordane, had residues of chlordane in their breast milk.97 A study was performed in mice to determine if chlordane might alter the immune system of mouse pups exposed to chlordane via the dam s milk.98 Female pups displayed... 

Krahn et al. [39] have described a high-performance liquid chromatographic method for the determination of 127 aromatic hydrocarbons and 21 chlorinated hydrocarbons in solvent extracts of marine sediments. 

Chlorinated hydrocarbons that have been determined in extracts of river sediments by gas chromatography include higher chlorinated aromatic hydrocarbons, alpha and gamma hexachlorocyclohexanes and dichlorobenzenes in amounts down to 0.5pg kg 1 in the sediment [28-30]. 

Aerobic degradation has been shown to be most effective in reducing the concentration of aliphatic and aromatic hydrocarbon fuel compounds. Anaerobic reactions are more effective in degrading chlorinated hydrocarbons and long-chain animal fats and oils. Detailed study is necessary to determine the most-effective procedure for a specific site. 

Bush B, Barnard EL. 1982. Determination of nonpolar chlorinated hydrocarbons and polychlorinated biphenyls in microsamples. Anal Lett 15(20) 1643-1648. 

A variety of miscellaneous elements can also occur in a residual fuel oil fraction. For example, chlorine is present as a chlorinated hydrocarbon and can be determined (ASTM D808, D1317, D6160). A rapid test method suitable for analysis of samples by nontechnical personnel is also available (ASTM D5384) and uses a commercial test kit where the oil sample is reacted with metallic sodium to convert organic halogens to halide, which is titrated with mercuric nitrate using diphenyl carbazone indicator. Iodides and bromides are reported as chloride. 

Although we can measure the amount of chloroform in the air that you breathe out, and in blood, urine, and body tissues, we have no reliable test to determine how much chloroform you have been exposed to or whether you will experience any harmful health effects. The measurement of chloroform in body fluids and tissues may help to determine if you have come into contact with large amounts of chloroform. However, these tests are useful only a short time after you are exposed to chloroform because it leaves the body quickly. Because it is a breakdown product of other chemicals (chlorinated hydrocarbons), chloroform in your body might also indicate that you have come into contact with those other chemicals. Therefore, small amounts of chloroform in the body may indicate exposure to these other chemicals and may not indicate low chloroform levels in the environment. From blood tests to determine the amount of liver enzymes, we can tell whether the liver has been damaged, but we cannot tell whether the liver damage was caused by chloroform. 

Chai M, Arthur CL, Pawliszyn J, et al. 1993. Determination of volatile chlorinated hydrocarbons in air and water with solid-phase microextraction. Analyst (Cambridge, U. K.) 118(12) 1501-1505. 

Ramus TL, Hein SJ, Thomas LC. 1984. Determinations of chlorinated hydrocarbons by gas chromatography using response factors calibration. J Chromatogr 314 243-251. 

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