High-performance liquid methods

High Performance Liquid Chromatography (hpic). Hplc is currently the fastest growing analytical method and is now available in many laboratories. DL-Analysis by hplc has already been described and hplc methods have been reviewed (122). 

Typically, quantitative protein determination is done on the one hand by colorimetric or nephelometric methods, on the other hand for more difficult analytical problems by more sophisticated techniques such as high performance liquid chromatography (HPLC), gel-electrophoresis and immunoassay. However, these methods are tedious, time-consuming and expensive. 

For selective estimation of phenols pollution of environment such chromatographic methods as gas chromatography with flame-ionization detector (ISO method 8165) and high performance liquid chromatography with UV-detector (EPA method 625) is recommended. For determination of phenol, cresols, chlorophenols in environmental samples application of HPLC with amperometric detector is perspective. Phenols and chlorophenols can be easy oxidized and determined with high sensitivity on carbon-glass electrode. 

As a method of research, has been used high-performance liquid chromatography in reversed - phase regime (RP HPLC). The advantage of the present method is the following the additional information about AIST and FAS composition (homologous distribution) simple preparation of samples (dilution of a CS sample of in a mobile phase). 

E.D. Katz (Ed.), High Performance Liquid Chromatography Principles and Methods in Biotechnology, J. Wiley Sons, Chichester, 1996. ISBN 0471934445. 

Lab method with high performance liquid chromatography after collection in an impinger containing water Charcoal adsorption tube and gas chromatography... 

Lab method using glass-fibre/Tenax tube sampling and high performance liquid chromatography Field method using acid hydrolysis, diazotization, coupling and spectrophotometry... 

Eormaldehyde in air Lab method using diffusive sampler, solvent desorption and high performance liquid chromatography 78... 

Hydrazine in air Lab method using sampling either onto acid-coated glass-fibre filters followed by solvent desorption or into specially constructed impingers. Linal analysis by derivatization and high performance liquid chromatography 86... 

As a result of these merits thin layer chromatography finds application all over the world. The frequency of its application is documented in Figure 3. This CA search only includes those publications where TLC/HPTLC are included as key words. The actual application of the method is very much more frequent. The method is employed as a matter of course in many areas of quality control and routine monitoring of product purity. This was also true in the 1970s when the rapid development of high performance liquid chromatography (HPLG) led to a... 

D. Wu, M. Berua, G. Maier and J. Johnson, An automated multidimensional sa eening approach for rapid method development in high-performance liquid cliromatography , 7. Pharm. Biomed. Anal. 16 57-68 (1997). 

C.-Y. Hsieh and J.-D. Huang, Two-dimensional high-performance liquid cliromato-grapliic method to assay p-hydroxyphenylphenylhydantoin enantiomers in biological... 

High performance liquid chromatography (HPLC) is an excellent technique for sample preseparation prior to GC injection since the separation efficiency is high, analysis time is short, and method development is easy. An LC-GC system could be fully automated and the selectivity characteristics of both the mobile and stationary... 

Despite the difficulties caused by the rapidly expanding literature, the use of chiral stationary phases (CSPs) as the method of choice for analysis or preparation of enantiomers is today well established and has become almost routine. It results from the development of chiral chromatographic methods that more than 1000 chiral stationary phases exemplified by several thousands of enantiomer separations have been described for high-performance liquid chromatography (HPLC). 

High performance liquid chromatography is used for the separation and quantitative analysis of a wide variety of mixtures, especially those in which the components are insufficiently volatile and/or thermally stable to be separated by gas chromatography. This is illustrated by the following method which may be used for the quantitative determination of aspirin and caffeine in the common analgesic tablets, using phenacetin as internal standard where APC tablets are available the phenacetin can also be determined by this procedure. 

As alkanesulfonates are mixtures of homologs as well as isomers, high-performance liquid chromatography (HPLC) proves to be a general method for an exact analysis. For identifying the raw material basis (carbon number cut of normal paraffins used), the carbon number distribution of the homologs can be... 

Commercially available poiybrominated aromatic ethers have been analyzed by reversed phase high performance liquid chromatography. NMR spectra of material isolated by preparative methods served to identify the observed peaks as congeners of tetrabromo to nonabromo diphenyl ether. A bromination pathway was clearly indicated. 

In 1979, it was stated that poiybrominated aromatic ethers have received little attention (ref. 1). That statement is still applicable. Analyses to characterize this class of commercial flame retardants have been performed using UV (refs. 1-2), GC (refs. 1-6), and GC-MS (refs. 1-4). The bromine content of observed peaks was measured by GC-MS, but no identification could be made. The composition of poiybrominated (PB) diphenyl ether (DPE) was predicted from the expected relationship with polyhalogenated biphenyl, a class which has received extensive attention. NMR (refs. 3-6) was successfully used to identify relatively pure material which had six, or fewer, bromine atoms per molecule. A high performance liquid chromatography (HPLC) method described (ref. 1) was not as successful as GC. A reversed phase (RP) HPLC method was mentioned, but no further work was published. 

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