Analysis by HPLC

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). 

Sugar analysis by hplc has advanced greatly as a result of the development of columns specifically designed for carbohydrate separation. These columns fall into several categories. (/) Aminopropyl-bonded siHca used in reverse-phase mode with acetonitrile—water as the eluent. (2) Ion-moderated cation-exchange resins using water as the eluent. Efficiency of these columns is enhanced at elevated temperature, ca 80—90°C. Calcium is the usual counterion for carbohydrate analysis, but lead, silver, hydrogen, sodium, and potassium are used to confer specific selectivities for mono-, di-, and... 

The mass spectrum produced should provide unambiguous molecular weight information from the wide range of compounds amenable to analysis by HPLC, including biomolecules with molecular weights in excess of 1000 Da. The study of these types of molecule by mass spectrometry may be subject to limitations associated with their ionization and detection and the mass range of the instrument being used. 

It should be clear from a simple consideration of the large number of organic compounds amenable to analysis by HPLC, the peak widths obtained and from the desirability to obtain k values of between 1 and 10, that it is likely that a number of compounds will have closely similar k values. Identification using this parameter alone will not therefore be possible. 

A preliminary test for the biodegradability of the 3-phenyl- and 3-carbamoyl-2(lH)pyridones was conducted in a barnyard humus suspension. The analysis by HPLC showed some loss, and the fluorescent compounds seemed to be adsorbed onto the solid. The 3-carbamoyl-2(lH)pyridone (II) also hydrolyzed to 3-carboxylic acid-2(lH)pyridone both in the slurry test and in water solutions that had been left standing 1-2 weeks. In preliminary tests both the 3-phenyl- and the 3-carbamoyl-2(lH)pyridones apparently adsorbed to some extent on silica sand columns. In addition, the solubility of both 1-H compounds was somewhat low, 1.3 x 10 M for II, and 1.0 x 10 M for IV. 

Vol. 115. Trace and Ultratrace Analysis by HPLC. By Satinder Ahuja... 

Ahuja S, Dong MW. Handbook of pharmaceutical analysis by HPLC, Amsterdam, Elsevier Academic, 2005. 

Nonvolatile Nitrosamines In Tobacco. A method which we developed several years ago for the analysis of tobacco-specific nitrosamines (TSNA 31) involves extraction of tobacco with buffered ascorbic acid TpH 4.5) followed by partition with ethyl acetate, chromatographic clean-up on silica gel, and analysis by HPLC-TEA (Figure 9). Results obtained with this method for a large spectrum of tobacco products (Table IV), strongly support the concept that the levels of nitrate and alkaloids, and especially the methods for curing and fermentation, determine the yields of TSNA in tobacco products. Recent and as yet preliminary data from snuff analyses indicate that aerobic bacteria play a role in the formation of TSNA during air curing and fermentation. 

Nollet, L.M.L., Food Analysis by HPLC, 2nd ed., Marcel Dekker, New York, 2000. Gennaro, M.C., Abrigo, C., and CipoUa, G., HPLC analysis of food colors and its relevance in forensic chemistry, J. Chromatogr. A, 674, 281, 1994. Gratzfeld-Huesgen, A. and Schuster, R., HPLCfor Food Analysis A Primer, Hewlett-Packard Company, Palo Alto, CA, 1996. 

Steroid Analysis by HPLC Recent Applications, edited by Marie P. Kautsky... 

Alaiz, M., Navarro, J. L., Giron, J., and Vioque, E. (1992). Amino acid analysis by HPLC after derivatization with diethyl ethoxymethylenemalonate. /. Chromatogr. 591,181-186. 

Because of the nature of the method of development, analysis by HPLC is of necessity performed in a sequential manner. Eacht sample must individually undergo the same sequence of injection, separation, detection and column re-equilibration. The tiae ... 

Applications Chromatography is a preferred technique for additive analysis as it allows both separation of additives in a mixture and subsequent quantitation. Despite the developments in GC, this technique cannot separate many polymer additives. Even with its lower efficiency in comparison to GC, HPLC is today one of the cornerstones in a polymer additive laboratory. Judging by the number of publications in recent years, HPLC is first among analytical methods for additives (confirmation/identification/quantification). Most additives may be analysed by HPLC if they can be dissolved in an HPLC solvent and absorb UV light. Typical polymer/additive analyses are carried out using LPE followed by HPLC with UV or RI detection [605-611]. Verification of the identity of an analyte is then based on a combination of retention time, UV and RI evidence. RPLC is used most frequently for polymer/additive analysis, but normal-phase and SEC are also used. Consequently, techniques for additive analysis by HPLC are legion. 

The foliage of the food plants was ground and the pigments were extracted into warm methanol and saponified in 4% sodium hydroxide. The carotenoids were extracted into dichloromethane, dried, and redissolved in ethanol prior to an analysis by HPLC. 

A Cis disk has been used to remove chlorotriazine, atrazine, metabolites, organophosphorus compounds, phenylurea, and carbamate pesticides from seawater prior to analysis by HPLC [392],... 

Table 3 Drug Analysis by HPLC with CL Detection Using Ruthenium Complex... 

S. Ahuja and M.W. Dong, Handbook of Pharmaceutical Analysis by HPLC, Elsevier, Amsterdam, The Netherlands, 2005. 

In the investigation of methods for measurement of personal exposure, a method for measuring hydroquinone in air was evaluated, both in the laboratory and in the workplace. The method involved sampling the inhalable fraction onto a filter contained in a multi-holed sampler with a back-up of Tenax TA, followed by desorption into acetonitrile and analysis by HPLC. Desorption efficiency was shown to be effectively 100%. 13 refs. 

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