High-performance liquid identification/characterization

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. 

Wu, X. and Prior, R.L., Identification and characterization of anthocyanins hy high performance liquid chromatography-electrospray ionization-tandem mass spectrometry in common foods in the United States vegetables, nuts, and grains, J. Agric. Food Chem., 53, 3101, 2005. 

High-performance liquid chromatography has become an important technique for the analysis of peptides and has contributed to the identification and characterization of various classes of biologically active and flavor-enhancing peptides that have been isolated during the last few years. 

Superior sensitivity, efficiency, and specificity have made high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS), the predominant analytical technique for characterization and quantitative analysis of metabolites (Kostiainen et al., 2003 Ma et al., 2006 Prakash et al., 2007). Ion trap, triple-quadrupole, and quadmpole time-of-flight (Q-TOF) mass spectrometers are routinely used to profile and characterize metabolites in plasma and excreta (Ma et al., 2006). The combination of scan types and features available on mass spectrometers of different design (product ion, MS", neutral loss, precursor ion scans, accurate mass measurements) allows identification and characterization of putative and unexpected metabolites with or without little prior knowledge of biotransformation pathways of a given dmg molecule. 

Identification. Chromatographic methods (interpretation of fluorescing spots in thin layer chromatography or of UV absorption peaks and fluorescence light emission peaks in high performance liquid chromatography) allow fairly rapid and certain identification of FWAs [158-164], The same methods can be used for qualitative and quantitative characterization of the FWA purity in terms of fluorescent or nonfluorescent byproducts. 

Efficient purification performed by high-performance liquid chromatography (HPLC) and high-sensitivity gas chromatography-mass spectrometry (GC-MS) using a capillary column dramatically improved the purification and identification procedure for GAs as in other natural products. The improved sensitivity in instrumental analyses also requires a correspondingly smaller quantity of GAs for characterization. The purification procedure for GAs has become simpler than that in earlier decades. 

Microanalytical methods for BRs have also been developed (i) gas chromatography/ mass spectrometry (GC/MS) analysis of BRs as bismethaneboronate (BMB) derivatives (72) or methaneboronate-trimethylsilyl (MB-TMS) derivatives (75), (ii) high performance liquid chromatography (HPLC) analysis of BRs as bisboronate derivatives having a fluorophore or an electrophore (14), (iii) Radioimmunoassay (RIA) for BRs (75). Among these microanalytical methods, the GC/MS analysis has greatly contributed to the study on identification and characterization of a number of natural BRs. 

Therefore, the ability to characterize thousands of proteins of different physicochemical complexities which are found in nature at various levels of concentrations raises an immediate challenge to protein biochemists. Through the years, a variety of techniques have been used for the identification and characterization of various proteins and peptides in the assay and quality control of dmg substance and formulated dmg products. Some of these techniques include polyacrylamide gel electrophoresis (PAGE), high-performance liquid chromatogra-... 

Wu CS, Sheng YX, Zhang YH, Zhang JL, Guo BL. Identification and characterization of active compounds and their metabolites by high-performance liquid chromato-graphy/Fourier transform ion cyclotron resonance mass spectrometry after oral... 

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