HRGC

Figure 2.6 Gas cluotnatograni of a 10 ml test sample containing C I4 C26 alkanes in -hexane (about 1 ppb each) the earner gas (H2) inlet pressure was 2.5 bar for a 22 m X 0.32 mm id separation column coupled with a 2 m X 0.32 mm id uncoated precolumn (no vapour exit). Reprinted from Journal of High Resolution Chromatography, 9, K. Grob et al., Concunent solvent evaporation for on-line coupled HPLC-HRGC , pp. 95-101, 1986, with peimission from Wiley-VCH.

K. Grob, C. Walder and B. Schilling, Concuirent solvent evaporation for on-line coupled HPLC-HRGC , 7. High Resolut. Chromatogr. Chromatogr. Commun. 9 95-101 (1986). 

Pigure 3.1 shows several potential on-line modes of two-dimensional GC operation. These couplings demonstrate HRGC-HRGC performed by using a single heart-cut from the primary to the secondary column, multiple heart-cuts, transferred to multiple intermediate traps, and heart-cuts transferred to a multiple parallel secondary column configuration. 

S. Wu, W. H. Chatham and S. O. Farwell, Multidimensional HRGC for sample components with a wide range of volatilities and polarities , J. High Resolut. Chromatogr. 13 229-233 (1990). 

D. Haring, T. Konig, B. Withopf, M. Herderich and P. Schi eier, Enantiodifferentiation of a-ketols in sherry by one- and two-dimensional HRGC tecliniques , J. High Resolut. Chromatogr. 20 351-354 (1997). 

G. M. Frame, A collaborative study of 209 PCB congeners and 6 Aroclor s on 20 different HRGC columns. Part 2. Semi-quantitative Aroclor congener distributions . Anal. Chem. 70 714-722(1997). 

D. Hainzl, J. Burhenne and H. Pariar, HRGC-ECD and HRGC-NICI SIM quantification of toxaphene residues in selected marine organism by envir onmentally relevant chloroboT nanes as standard , Chemosphere 2S 237-243 (1994). 

J. Beens and R. Tijssen, An on-line coupled HPLC-HRGC system for the quantitative chai acterization of oil fractions in the middle distillate range , J. Microcolumn Sep. 7 345-354(1995). 

Figure 6.6 SPE-SFE-HRGC(PID) cliromatograms obtained for (a) a mixture of analytical standards of selected aromatic compounds in water, and (b) the analysis of a water sample contaminated with various aromatic compounds.

In 1996, Mondello et al. (48) published a review article on the applications of HPLC-HRGC developed for food and water analysis over the period from 1986 to 1995. These authors cited 98 references, grouped by following a chronological order and by the subject of the application, as follows ... 

The analysis of sterols, sterols esters, erythrodiol and uvaol, and other minor components of oils and fats, is usually carried out by normal-phase HPLC-HRGC by using a loop-type interface and the concurrent eluent evaporation technique, as reported in the papers cited by Mondello et al. (48) (up to 1995) and in more recent papers (49, 50). More recently, reversed-phase LC-GC methods have been... 

Mondello et al. (54) have developed some applications of on-line HPLC-HRGC and HPLC-HRGC/MS in the analysis of citrus essential oils. In particular, they used LC-GC to determine the enantiomeric ratios of monoterpene alcohols in lemon, mandarin, bitter orange and sweet orange oils. LC-GC/MS was used to study the composition of the most common citrus peel, citrus leaf (petitgrain) and flower (neroli) oils. The oils were separated into two fractions, i.e. mono- and sesquiterpene... 

Figure 10.11 Comparison of the mass spectra of a neroli oil peak (camphene) obtained by HPLC-HRGC-MS (a) and GC-MS (b) with a library specti um of the same compound (c). Reprinted from Perfumer and Flavorist, 21, L. Mondello et al., On-line HPLC- HRGC in the analytical chemistiy of citms essential oils , pp. 25-49, 1996, with permission from Allured Publishing Coip.

Analogous to HPLC-HRGC, the combination of packed column SEC and capillary column GC can be used for the analysis of complex samples. The advantage of SEC/GC with respect to HPLC/GC is the absence of problems associated with the evaporation of the HPLC mobile phase prior to the GC analysis. 

R Lanuzza, G. Micali and G. Calabro, On-line HPLC-HRGC coupling and simultaneous transfer of two different LC fractions determination of aliphatic alcohols and sterols in olive oil , 7. High Resolut. Chromatogr. 19 444-448 (1996). 

R. Mondello, G. Dugo, P. Dugo and K. Baitle, On-line HPRC-HRGC in the analytical chemistry of citms essential oils . Perfumer Flavorist 21 25-49 (1996). 

G. Pull, G. Ki-ammer and P. Sclneier, On-line coupled HPRC-HRGC A powerful tool for vapoi phase PTIR analysis (RC-GC-PTIR) , 7. High Resolut. Chromatogr. 14 160-163 (1991). 

F. Munari and K. Grob, Automated on-line HPLC-HRGC instnimental aspects and application for the determination of heroin metabolites in urine , J. High. Resolut. Chromatogr. Chromatogr. Commun. 11 172-176(1988). 

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