Study of the enantioselective elimination of four toxaphene congeners in rat after intravenous administration by high resolution gas chromatography negative ion mass spectrometry.

This study was performed to investigate the possible enantioselective metabolism of the four chlorinated bornanes: #26, #32, #50 and #62 (according to the Parlar nomenclature) by rats. Rats were exposed to a mixture of these toxaphenes by a single intravenous injection. Enantiomer ratios (ER) as well as the enantiomer fractions (EF) were determined in brain, adipose tissue and liver samples at six time intervals by high resolution gas chromatography (HRGC) coupled to negative ion chemical ionization (NICI) mass spectrometry (MS). Capillaries coated with heptakis-(2,3,6-O-tert-butyldimethylsilyl)-beta-cyclodextrin (TBDMS-CD) or octakis-(2,3,6-tri-O-ethyl)-gamma-cyclodextrin (TEG-CD) were used for the enantioselective separations. Significant time-dependent changes of ER and EF were found in all the three tissues for #26, #50 and #62. Greatest deviations from racemic composition were found in the liver, which is known to be the major metabolizing organ for toxaphenes. #32 was metabolized the fastest, but showed no changes in ER. Brief information is also included about the possible reasons for the different behaviors of the four congeners in the studied tissues.

Detection of chlordanes by positive ion chemical ionization in an ion trap: a comparative [correction of comparitive] study of the non-conventional reagents acetonitrile, acrylonitrile and dichloromethane.

The detection of some chlordane compounds (heptachlor, cis-/trans-chlordane and cis-/trans-nonachlor) by positive ion chemical ionization (PICI) in an ion trap was studied using acetonitrile, acrylonitrile and dichloromethane as non-conventional reagent gases. These reagent gases initiated specific fragmentation reactions and resulted in different response factors. All reagent gases enabled detection limits in the low-pg range for heptachlor, whereas the detection limits of cis-/trans-chlordane and cis-/trans-nonachlor were in the mid-pg range. Additionally, the acetonitrile and dichloromethane PICI mass spectra of the cis- and trans-stereoisomers of chlordane and nonachlor were different.