High-Speed Gas Chromatography—Multiplex Coherent Raman Analysis of BTEX

Chen, Peter C.; Cottingham, Kyndra A.; Royster, Rebecca M.; Joyner, Candace C.

doi:10.1366/000370205774783313

Cited by 2 publications

(1 citation statement)

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“…This would be similar to injecting a 3% solution of peppermint without splitting onto the column, which apparently would produce overloading. The collected mass range here would be sufficient for GCÀSERS detection of 50 ng DL (of benzene), 25 GCÀFTIR verification at 15 ng for nitrogen mustard derivatives, 26 and potentially adaptable for current online GCÀNMR analysis 11 that required 10s of micrograms of solute. In all cases, a higher phase load on the 2 D column would reduce the tendency for peak overloading.…”

Section: ' Results and Discussionmentioning

confidence: 99%

Universal Method for Online Enrichment of Target Compounds in Capillary Gas Chromatography Using In-Oven Cryotrapping

2011

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A method is described that permits automated online enrichment of injected compounds in multidimensional gas chromatography by using a microfluidic heart-cut (H-C) device to direct target compounds into a cryogenically cooled internal trap (cryotrap, CT). By performing multiple injections of a sample, selected compounds or regions of a primary column separation can be collected in the CT. Remobilizing the trapped species allows elution and further resolution on the second column. Using a well-balanced H-C device, compounds can be fully excluded from the collection step or quantitatively transferred to the CT. Peak areas of the remobilized compound correlate well with the number of sample injections. Trapping on various column phases shows the method is suited to quantitative trapping of alkanes of mass greater than about dodecane and fatty acid methyl esters greater than the C8 homologue. Caffeine and menthol standards of concentration 100 μg mL(-1) gave peak area correlation coefficients for 1-10 and 1-50 replicate split injections of 1 μL volume of 0.999 and 0.996, respectively. Peak height correlations were less favorable as a result of peak broadening on the second column, presumably due to overloading at greater collected mass. The method was applied to 0.2% solutions of peppermint oil (menthol; a major component; 44%) and 1.0% lavender oil (α-terpineol and neryl acetate; minor components of 1.05 and 0.42% abundance). The minor components gave good area and height correlations, and good recovery around 90% was observed for menthol compounds recovered from 15 accumulations. Response amplification was further demonstrated for menthol from mint oil headspace sampling using solid phase microextraction. This approach should be a valuable adjunct for improved detection specificity, for detectors of low sensitivity, and when prior sample concentration provides insufficient response of selected target analytes.

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Section: ' Results and Discussionmentioning

confidence: 99%