Liquid chromatography/mass spectrometry optimization

During gc/ms or liquid chromatography/mass spectrometry (Ic/ms) acquisitions, it is possible to perform a mixture of the experiments described in Table 2 for different time windows, with the experimental parameters, such as the coUision energy, optimized for each analyte. 

R.D. Voyksner, C.S. Smith and P.C. Knox, Optimization and application of particle beam high-performance liquid chromatography/mass spectrometry to compounds of pharmaceutical interest, Biomed. Environ. Mass Spectrom., 19 (1990) 523-534. 

Liquid chromatography mass spectrometry (LC-MS) is now routinely used in analytical laboratories. Traditional IPRs are non-volatile salts that are not compatible with MS techniques because they play a major role in source pollution that is responsible for reduced signals. Moreover the final number of charged ions that reach the detector is impaired by ion-pair formation actually IPRs added to the mobile phase to improve analytes retention exert a profound effect on analyte ionization. Chromatographers who perform IPC-MS must optimize the eluent composition based on both chromatographic separation and compatibility with online detection requirements. 

Sun, Y. Liao, X. Wang, Z. Hu, X. Chen, F. 2007. Optimization of microwave-assisted extraction of anthocyanins in red raspberries and identification of anthocyanin of extracts using high-performance liquid chromatography mass spectrometry. Eur. Food Res. Tech. 225 511-523. 

Voyksner, R. D. and Haney, C. A. Optimization and application of thermospray high-performance liquid chromatography/mass spectrometry. Anal. Chem. 57 991-996, 1985. 

As FIA-MS and liquid chromatography mass spectrometry (LC-MS) become more pervasive in the analysis of compound libraries, open-access instrumentation is increasingly used in HTOS laboratories as well as in support of general medicinal chemistry. These open-access systems are most often used for reaction monitoring and optimization, and in some cases, for library quality control and synthesis product purification. 

A solid-phase variant of the above synthesis utilized previously prepared MBHA-AB resin-bound 232 in reaction with sulfamyl chloride. The crude product from treatment of 233 with l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) for 48 h was analyzed by liquid chromatography-mass spectrometry (LC-MS), which indicated the presence of the desired product 234 as the major component (56%) of the mixture. A significant amount (26%) of unidentified material (mlz = Zil) was also present. As the focus of this work was preparation of sulfahydantoins, the effort to optimize the synthesis of 234 was not undertaken (Scheme 28) <2001JC0290>. 

See also Chemometrics and Statistics Optimization Strategies. Chromatography Overview Principies. Derivatization of Analytes. Extraction Soivent Extraction Principies Solid-Phase Extraction. Forensic Sciences Systematic Drug Identification. Gas Chromatography Mass Spectrometry. Hormones Steroids. Liquid Chromatography Liquid Chromatography-Mass Spectrometry. Mass Spectrometry Atmospheric Pressure Ionization Techniques Forensic Applications. 

Leinonen, A. Kuuranne, T. Kostiainen, R. Liquid chromatography/mass spectrometry in anabolic steroid analysis—optimization and comparison of three ionization techniques Electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photoionization. J. Mass Spectrom. 2002, 37 (7), 693-698. 

Liquid chromatography-mass spectrometry (LC-MS) is an extremely power tool for the analysis of peptides, providing not only information on the purity of the product but also coMormation of structures. The s)rstem typically consists of a microbore HPLC system coupled to an electrospray mass spectrometer. Using such a system the composition of a crude peptide mixture can be quickly determined and by-products identified, enabling synthetic protocols to be rapidly optimized. 

Turrell E, Stobo L, Lacaze JP, Piletsky S, Piletska E (2008) Optimization of hydrophilic interaction liquid chromatography/mass spectrometry and developmtait of solid-phase extraction for the determination of paralytic shellfish poistming toxins. J AOAC Int 91 1372-1386... 

Wang L, Sun HW, Yang LR, He C, Wu WL, Sun SJ, et al. Liquid chromatography/ mass spectrometry analysis of perfluoroalkyl carboxylic acids and per-fluorooctanesulfonate in bivalve shells extraction method optimization. J Chromatogr A 2010 1217(4) 436-42. 

K. K. Chee, M. K. Wong, H. K. Lee, Optimization of microwave-assisted solvent extraction of polycyclic aromatic hydrocarbons in marine sediments using a microwave extraction system with high-performance liquid chromatography-fluorescence detection and gas chromatography-mass spectrometry. Anal. Chim. Acta. 330 (1996), 217. 

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