Organic chlorine determination

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. 

Organic-Chlorine Determinations as a Measure of Insecticide Residues in Agricultural Products... 

Because the results obtained reflect the presence, not only of the insecticide in question, but also of any of its decomposition products or other organic compounds containing halogen, confirmatory evidence of the identity and amount of the residues was desired, Therefore, studies to correlate the results of organic-chlorine determinations with insecticidal activity were undertaken. 

CARTER, NELSON, AND GERSDORFF—ORGANIC-CHLORINE DETERMINATIONS... 

The tests reported in this paper were intended only to show general agreement between the insecticide level calculated from organic-chlorine determinations and fly mortality. 

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. 

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. 

Paschke, A., Popp, P., Schuurmann, G. (1999) Water solubility and octanol/water-partitioning of hydrophobic chlorinated organic substances, determined by using SPME/GC. Fresenius J. Anal. Chem. 360, 52-57. 

Thompson RS, Gillings E, Cumming RI (1998) Short-chain chlorinated paraffin (55% chlorinated) determination of organic carbon partition coefficient. Zeneca Confidential Report BL6426/B... 

A method for the determination of total organic chlorine content of water was described (121), based on the combustion of organic compounds to produce HCl which was subsequently detected with a crystal coated with amine 220. The reported detection limit was in the order of 100 pg of HCl, and 3 ppb of chloroform were detectable in a 100 fjl aqueous sample. 

Having thus standardized the method for estimating organic chlorine, coal samples crushed to pass through a 240 mes BS, or 6 mesh (64 ym) 15 sieve, are put in the boat and their organic chlorine contents determined as described for the standardization. 

The presence of other oxidizing agents such as manganese(IV) can interfere with the chlorine determination if the titration is performed at pH<3.5. Under this condition, the organic chloramines are often converted to either monochloramine or dichloramine, resulting in positive errors for these substances. Also, the volatilization of chlorine compounds can result in low recoveries. This can occur due to the violent agitation or aeration of some of the chloramines prior to the addition of iodide. 

Manninen, P. K. G. (1994). Determination of extractable organic chlorine by electrothermal vaporization inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 9(3), 209-212. 

Control experiment. This is not necessary if the sodium peroxide is known to be chlorine-free. If there is any doubt on this point, the whole operation should be repeated precisely as before, but omitting the organic halogen compound. A small thiocyanate titration value may be found, and this should be deducted from all determinations in which the above quantity of the particular batch of sodium peroxide is used. 

Solvent extraction followed by gas chromatographic analysis is used to determine paraffin wax antioxidants (qv), ie, butylated hydroxyanisole and butylated hydroxytoluene and other volatile materials. Trace amounts of chlorinated organic compounds, eg, polychlorinated biphenyls, can be deterrnined by using a gas chromatograph with an electron-capture detector (22). 

Environmental. In general, chlorinated paraffins biodegrade the rate is determined by chlorine content and carbon chain length. Microorganisms previously acclimatized to specific chlorinated paraffins show a greater ability to degrade the compounds than nonacclimatized organisms. Mammals and fish have been shown to metabolize chlorinated paraffins (8). 

SW-846, is used to measure emissions of semivolatile principal organic constituents. Method 0010 is designed to determine destruction and removal efficiency (DRE) of POHCs from incineration systems. The method involves a modification of the EPA Method 5 sampling train and may be used to determine particulate emission rates from stationary sources. The method is applied to semivolatile compounds, including polychlorinated biphenyls (PCBs), chlorinated dibenzodioxins and dibenzofurans, polycyclic organic matter, and other semivolatile organic compounds. 

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