Reversed phase liquid chromatography and gas

Maniongui, C., Gresti, J., Bugaut, M., Gauthier, S. and Bezard, J. (1991) Determination of bovine butterfat triacylglycerols by reversed-phase liquid chromatography and gas chromatography. J. Chrom., 543, 81-103. 

Reversed-phase liquid chromatography and gas-liquid chromatography have been applied to studies on the complexation of cyclodextrin with isomeric dime-thylnaphthalenes (DMN) 19-22. Both / - and y-CyD have been found to form inclusion complexes with them. With the exception of the complex of 1,8-DMN 22 with yS-CyD, all other complexes under investigation are of weak stability. The stability constant of the former complex is always about 1.5-2.0 orders of magnitude greater than the corresponding value for the other isomers [47]. For example, at 40 °C in 40% of ethanol in water solvent, the stability constants of the complexes of yS-CyD with 1,8-DMN 22 and 1,3-DMN 19 are equal to ca. 500 and ca. 8 respectively. 

A recent analytical procedure by Flores et al. targeted the optimization of the interface performance in the online coupling of reversed phase liquid chromatography and gas chromatography (RPLC-GC) coupling by means of a horizontally positioned PTV (Programmed Temperature Vaporizer) injector. It improved the sensitivity achievable in the direct analysis of olive oil-mixtures with 5% or 12% of some virgin and refined hazelnut oils, respectively, based on the analysis of fil-bertone enantiomers within 30 min and without any kind of pretreatment. 

Gaydou, E. M., Bianchini, J.-P. and Ralaimanarivo, A. (1983) Determination of cyclopropenoic fatty acids by reversed-phase liquid chromatography and gas chromatography. Anal Chem., 55, 2313-17. 

Senorans, R J., Reglero, G., and Herraiz, M., Use of a programmed temperature injector for on-line reversed-phase liquid chromatography-capillary gas chromatography, /. Chromatogr Sci, 33, 446, 1995. 

K. Grob and Z. Li, Coupled reversed-phase liquid chromatography-capillary gas chromatography for the determination of atrazine in water , J. Chromatogr. 473 423 -430 (1989). 

T. Hyotylainen and M-L. Riekkola, Direct coupling of reversed-phase liquid chromatography to gas chromatography , J. Chromatogr. 819 13 - 24 (1998). 

F. J. Senorans, J. Tabera and M. Herraiz, Rapid separation of free sterols in edible oils by on-line coupled reversed phase liquid chr omatography-gas chromatography , 7. Agric. Food. Chem. 44 3189-3192 (1996). 

One of the first examples of the application of reverse-phase liquid chromatography-gas chromatography for this type of analysis was applied to atrazine (98). This method used a loop-type interface. The mobile phase was the most important parameter because retention in the LC column must be sufficient (there must be a high percentage of water), although a low percentage of water is only possible when the loop-type interface is used to transfer the LC fraction. The authors solved this problem by using methanol/water (60 40) with 5% 1-propanol and a precolumn. The experimental conditions employed are shown in Table 13.2. 

T. Hyotylainen, K. Jauho and M-L. Riekkola, Analysis of pesticides in red wines by online coupled reversed phase liquid chromatography with a vaporizer/precolumn solvent split/gas discharge interface ,/. Chromatogr. 813 113-119(1997). 

E. C. Goosens, D. de Jong, G. J. de Jong and U. A. Th Brinkman, Reversed-phase liquid chromatography coupled on-line with capillary gas chromatography. II. Use of a solvent vapor exit to increase introduction volumes and introduction rates into the gas chromatograph , J. Microcolumn Sep 6 207-215 (1994). 

T. Hyotylainen, H. Keski-Hynnila and M. L. Riekkola, Determination of morphine and its analogues in urine by on-line coupled reversed-phase liquid chromatography-gas chromatography with on-line denvatization, J. Chromatogr. A 771 360-365 (1997). 

The liquid chromatographic procedure [622] uses reversed phase liquid chromatography with fluorescence detection to separate all 16 PAHs completely. The method is sensitive and so selective as often to allow the method to be applied without clean-up procedure. For gas chromatographic methods, detection limits are about lpg L 1 whereas for the liquid chromatographic methods, limits are between 1 and lOOpg L 1 for two- and three-ring aromatics and below lpg L 1 for the four-, five- and six-ring compounds. 

Blanch, G.P., Villen, J. and Herraiz, M. (1998) Rapid analysis of free erythrodiol and uvaol in olive oils by coupled reversed phase liquid chromatography—gas chromatography. J. Agric. Food Chem., 46, 1027-1030. 

Whilst gas chromatography has been used for the analysis of many of the lycoctonine-based alkaloids [52], the larger, less volatile, and more thermally labile MSAL compounds require analytical procedures such as TLC and HPLC for separation and detection. For example, both normal phase liquid chromatography [53] and reversed phase liquid chromatography [54] with UV detection have been used for separation, detection, and quantitation of alkaloids from Delphinium species associated with livestock poisonings in the western US and Canada. The introduction of API techniques has allowed the analysis of all types of diterpene alkaloids by direct MS methods and with MS methods coupled to liquid chromatography. 

In order to determine ureas and metabolites of triazines and ureas in agricultural soils, reverse-phase liquid chromatography was used with atmospheric pressure chemical ionization/mass spectrometry (APCI/MS), in positive mode. Gas chromatography/ion trap mass spectrometry was used in MS/MS mode to analyze the parent compounds of the triazines and chloroacetanilides. Method performance was much better in GC-MS/MS than in LC-MS, and acetochlor LOQ was dramatically improved by using GC-MS/MS, this herbicide being very poorly ionized into the APCI interface. 

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