GLC and HPLC

GLC and HPLC Determination of Therapeutic Agents (in three parts). Part 1 edited by KiyoshI TsujI and Walter Morozowich, Parts 2 and 3 edited by Kiyoshi TsujI... 

Under conditions similar to those for (XMe2Si)20, the acid catalyzed cleavages with alcohols of linear and cyclic methylsiloxanes have been investigated. The rate constants of the primary reaction, the cleavage of the first Si-O-Si-bond, determined by GLC and HPLC, are given in Table 2. 

Perry JA, Feit CA. 1978. Derivatization techniques in gas-liquid chromatography. GLC and HPLC Determination of Therapeutic Agents, Part 1, Tsuji K. Marozowich W, editors. New York Marcel Dekker pp. 137—208. 

For GLC and HPLC analysis, the extraction of total lipids from food requires overnight separation of the organic layer. If the sample volume is small, however, centrifugation of the extract may shorten the sample preparation time. Cholesterol derivatization requires <2 hr depending on the number of samples. The peak of TMS ether and cholesterol benzoate derivatives will be eluted within 10 min after the injection of the sample. 

Use of bound laboratory notebooks occurs in the Feed and Fertilizer Section but not in the Pesticides Section. Data trail proceeding from final report backwards to original chromatograms (GLC and HPLC) or spectrometer... 

Organic solvents for HPLC are generally very good. There are three rules of thumb to remember always use HPLC grade solvents, buy from a reliable supplier, and filter your solvents and check them periodically with your HPLC. Most manufacturers do both GLC and HPLC quality control on their solvents some do a better job than others. The best way to find good solvents is to talk to other chromatographers. 

Another way to obtain pure enantiomers is the separation of racemates through preparative chromatography on chiral stationary phases. In fact, the most significant developments over the last 20 years have been the application of GLC and HPLC techniques to the effective resolution of enantiomeric mixtures and to determining the enantiomeric ratio [7,8],... 

T. Daldrup, F. Susanto, and P. Michalke, Combination of TLC, GLC and HPLC for a rapid detection of drugs and related compounds, FreseniusZ. Anal. Chem., 308 413 (1981). 

R. Milberg and J. Cook, The mass spectrometer as a detector for gas-liquid chromatography. In GLC and HPLC Determination of Therapeutic Agents, Marcel Dekker, New York, pp. 235-258. 

I. I. Hewala, GLC and HPLC determination of diazepam and its degradation products in pharmaceutical formulations, Anal. Lett., 25 1877(1992). 

GLC and HPLC Analyses of Cannabinoids in Biological Fluids and Applications... 

GLC and HPLC are powerful techniques for analyzing lipids. GLC is particularly useful for analysis of fatty acid mixtures or fatty acid methyl esters derived from isolated lipid classes or specific... 

Empirical methods have been used to characterize the retention behavior of a variety of solutes in GLC and HPLC (high-performance liquid chromatography)... 

Tsuji, K. GLC and HPLC Determination of Therapeutic Agents Tsuji, K., Morozowich, W., Tsuji, K., Eds. Part 1, Parts 2 and 3 Chromatographic Science Series Marcel Dekker, Inc. New York, 1979 9. 

Many antiepileptic drugs are used to treat seizures (Table 33-i). Most are analyzed collectively by either GLC or HPLC or individually analyzed by immunoassay. The advantage of HPLC or GLC is that simultaneous analyses can be accomplished. Immunoassay procedures are less labor intensive and are usually quicker than HPLC or GLC for a single analyte however, analysis of multiple antiepileptics or metabolites requires additional assays. For example, GLC and HPLC methods allow for the simultaneous measure of several common anticonvulsants. Immunoassay, however, is the mainstay of monitoring these drugs in most clinical laboratories. 

Of these, capillary GLC and HPLC are providing the main thrust In ultrahlgh resolution chromatography. Supercritical fluid chromatography Is opening some new avenues and, hopefully, will provide resolution that Is not possible now with GLC or HPLC. Hence, mainly these subjects have been covered In this book. Whereas, some Improvements In resolution have been obtained with HPTLC, further Improvements are possible In the area of detection and quantification. Ultrahlgh resolution with the other modes of separation still remains within the domain of a handful of experts. Some Information Is Included on these under Miscellaneous techniques, however, a detailed discussion of these techniques Is deferred to a future symposium. 

The introduction of molecular genetics into the field of pesticide chemistry, has in a few years, resulted in the development of a new class of pest control agents. These agents have presented a new challenge to the environmental chemist. In many situations, classical GLC and HPLC procedures are no longer applicable to the analyses of these complex biological and/or biochemical materials. 

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