Correlation gas chromatography

Verevkin, S.P., Wandschneider, D., Heintz, A. (2000) Determination of vaporization enthalpies of selected linear and branched C7, C8, C9, Cu and Cu monoolefin hydrocarbons from transpiration and correlation gas-chromatography methods. J. Chem. Eng. Data 45, 618-625. 

The first experiments directed to trace analysis were carried out in correlation gas chromatography ( 2 ). However, in the recent years much attention was paid to correlation HPLC, because the detection is generally more a problem than in GC and because injection is inherently easier. Results with a first experimental set-up and an off-line computer calculation of the CCF were very promising. 

Correlation gas chromatography is an indirect method to determine the enthalpies of vaporization of both solids and liquids [99]. The quantity directly measured is the enthalpy of transference from the condensed state in the column to the gas state. The enthalpy of vaporization is obtained by using the equation obtained by regression analysis between the enthalpies of transference and the... 

During the last decade, a number of sublimation enthalpies have been measured by transpiration or transference techniques [91,199-204]. The data obtained with this method are in agreement with those obtained by the Knudsen cell mass-loss effusion method, correlation gas chromatography [205] and thermogravimetry [206]. 

Through combined combustion calorimetry, correlation-gas chromatography... 

When simple Hquids like naphtha are cracked, it may be possible to determine the feed components by gas chromatography combined with mass spectrometry (gc/ms) (30). However, when gas oil is cracked, complete analysis of the feed may not be possible. Therefore, some simple definitions are used to characterize the feed. When available, paraffins, olefins, naphthenes, and aromatics (PONA) content serves as a key property. When PONA is not available, the Bureau of Mines Correlation Index (BMCI) is used. Other properties like specific gravity, ASTM distillation, viscosity, refractive index. Conradson Carbon, and Bromine Number are also used to characterize the feed. In recent years even nuclear magnetic resonance spectroscopy has been... 

Using a simple solvent extraction procedure to minimize matrix effects, a diclofop-methyl immunoassay was developed for milk, a number of edible plant products, and other matrices. Gas chromatography (GC) and liquid scintillation counting (LSC) of a C-labeled analyte were used as reference methods to compare with enzyme immunoassay (EIA) results. The methods were well correlated, with comparison of EIA... 

Davis, J.M. (2004). Assessment by Monte Carlo simulation of thermodynamic correlation of retention times in dual-column temperature programmed comprehensive two-dimensional gas chromatography. J. Sep. Sci. 27, 417. 

Smith [83] classified large sets of hydrocarbon oil infrared spectral data by computer into correlation sets for individual classes of compounds. The correlation sets were then used to determine the class to which an unknown compound belongs from its mass spectral parameters. A correlation set is constructed by use of an ion-source summation, in which a low resolution mass spectrum is expressed as a set of numbers representing the contribution to the total ionisation of each of 14 ion series. The technique is particularly valuable in the examination of results from coupled gas chromatography-mass spectrometry of complex organic mixtures. 

Tabor and Barber examined the 2800 km reach of the Mississippi river for the occurrence and fate of LAS in waters and bottom sediments [3], Dissolved LAS was concentrated on reversed-phase (RP)-Cis solid-phase extraction (SPE) cartridges, while sediment-bound LAS was extracted with methanol in three 24-h cycles on a rotating mixer. After derivatisation of the extracts to yield the trifluoroethyl esters, analyses were performed by gas chromatography mass spectrometry (GC-MS). Upon enrichment of 900 mL samples, detection limits of 0.1p.gL 1 were achieved. LAS was identified in 21% of the water samples at concentrations ranging from 0.1 to 28 p,g L-1 and was detected at all of the Mississippi river sediment samples at concentrations ranging from 0.01 to 20 mg kg-1 with a mean value of 0.83 mg kg-1. The concentrations of LAS sorbed onto sediment particles generally did not correlate with... 

Konig WA, Enantioselective capillary gas chromatography in the investigation of stereochemical correlations of terpenoids. Chirality 10 499—504, 1998. 

Detection techniques. Detection techniques commonly used for CO include two infrared techniques, TDLS and NDIR (also known as gas filter correlation, GFC), and gas chromatography with various detectors. The principles behind TDLS and NDIR have been... 

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