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Written by The Clever Chromatographer
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Monday, 09 November 2009 19:04 |
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A recent article appeared in JCA featuring the combination of counter-current chromatography and GC-MS to unravel a complex mixture of chlorinated camphenes called compounds of technical toxaphene (CTTs). The article is entitled “offline coupling of high-speed counter-current chromatography and gas chromatography/mass spectrometry generates a two-dimensional plot of toxaphene” JCA 1216 (2009) p. 8391. An n-hexane/methanol/water solvent system spread out the mixture in to over thirty 9 mL fractions. Each fraction was monitored by GC-MS. Due to lack of standard compounds it is not possible to definitively identify the components by GC-MS but the number of substituted chlorines can be easily discerned with mass spectrometry. The two-dimensional plot was generated by plotting the CCC fraction number against GC retention time. Each GC peak was labeled with the number of chlorines giving the plot a third dimension. Predictably, the GC column separates the components by the number of chlorine substituents. Hepta and octa substituted camphenes make up the majority of detected components and they overlap quite a bit in the GC eluant. Interestingly, the CCC fractions do not follow the substitution number pattern at all. At least one hepta-substituted camphene is present in every fraction from 7 to 39. Octa-substituted camphenes have a similar distribution. In brief, the CCC separation is quite orthogonal to that of the GC column. The authors claim that 362 different compounds of technical toxaphene were detected in this study.
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Last Updated on Sunday, 16 May 2010 07:04 |
