background and objectives:  high concentration of preservatives in food may result in gastrointestinal disturbances whereby some patients suffering from asthma, rhinitis, or urticaria. the aim of this study is the introduction and optimization a new method for simultaneous determination of four preservatives (sb, ps, mp, pp) in foodstuff by high performance liquid chromatography. materials and ...

Prostate-specific antigen (PSA) was purified to homogeneity from human seminal plasma by ion-exchange chromatography on a CM-Sephadex C-50 and by gel filtration on a Sephacryl S-200 column. A single 33-kDa protein band appeared in SDS-PAGE. High pressure liquid chromatography (HPLC) of the purified protein produced a single peak, while isoelectric focusing demonstrated the presence of five diff...

An isocratic reversed-phase high-pressure liquid chromatographic method for the determination of six components of the teicoplanin complex in biological fluid was developed. By using fluorescence detection after precolumn derivatization with fluorescamine, the assay is specific and highly sensitive, with reproducibility studies yielding coefficients of variation ranging from 1.5 to 8.5% (at 5 t...

Ion-exclusion high-pressure liquid chromatography (HPLC) was used to measure poly-beta-hydroxybutyrate (PHB) in Rhizobium japonicum bacteroids. The products in the acid digest of PHB-containing material were fractionated by HPLC on Aminex HPX-87H ion-exclusion resin for organic acid analysis. Crotonic acid formed from PHB during acid digestion was detected by its intense absorbance at 210 nm. T...

The development of high-performance liquid chromatography (HPLC) in the years of 1965 to 1985 was undeniably a success story. However, an important limitation of the technique remained: in comparison to capillary gas chromatography the resolving power accessible in a reasonable analysis time is poor. The introduction of a range of miniaturized liquid phase techniques, exploiting either pressure...

Submit Manuscript | http://medcraveonline.com Abbreviations: ANVISA: National Health Surveillance Agency; BHA: mixture of 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl4-hydroxyanisole; BHT: 3,5-di-tert-butyl-4-hydroxytoluene; CGMS: Gaseous Chromatography coupled to Mass Spectrometry; HPLC: High Pressure Liquid Chromatography; PG: Propyl 3,4,5-trihydroxybenzoate or Propyl Gallate; TBHQ: Tertbut...

of isotopically labelled vitamin D metabolites by HPLC. Journal of Chromatography 303: 229}233. Kaspersen FM, van Acquoy J, van de Laar GLM, Wagenaars GN and Funke CW (1984) Deuterium isotope effects in mianserin. Recueil Travaux Chimique de Pay-Bas 103: 32}36. Klein PD (1966) Occurence and signiRcance of isotope fractionation during analytical separation of large molecules. Advances in Chromat...

Preparative HPLC 5}30 '20 2}20 0.01}1 High purity solvent required Higher resolution See also: II/Chromatography: Countercurrent Chromatography and High-Speed Countercurrent Chromatography: Instrumentation. Chromatography: Liquid: Countercurrent Liquid Chromatography. III/Alkaloids: Gas Chromatography; High-Speed Countercurrent Chromatography; Liquid Chromatography; Thin-Layer (Planar) Chromato...

Determination of sildenafil by various methods and in various media is reviewed in this paper. The methods used consist of ultraviolet (UV) spectroscopy, thin layer chromatography (TLC), and high-performance liquid chromatography (HPLC). These methods were used to determine the amount of sildenafil in pharmaceutical preparations, soft drinks, and biological liquids. HPLC was used for evaluation...

Abbreviations and trivial names: chenodeoxycholate, 3a,7adihydroxy-5p-cholanate; TLC, thin-layer chromatography; PLC, preparative-layer chromatography; HPLC, high-pressure liquid chromatography; PMR, proton magnetic resonance spectroscopy; GLC, gas-liquid chromatography; MS, mass spectrometry. Address correspondence to William H. Elliott, E. A. Doisy Department of Biochemistry, St. Louis Univer...