Liquid chromatography-mass estimation

High performance liquid chromatography-mass spectrometric methods Nitin et al. [75] developed and validated a sensitive and selective liquid chromatography-tandem mass spectrometric method (LC MS MS) for the simultaneous estimation of bulaquine and its metabolites primaquine in monkey plasma. The mobile phase consisted of acetonitrile ammonium acetate buffer (20 mM, pH 6) (50 50, v/v) at a flow rate of 1 mL/min. The chromatographic separations were achieved on two Spheri cyano columns (5 pm, 30 cm x 4.6 mm), connected in... 

Burkhard, L.P., Kuehl, D.W., Veith, G.D. (1985) Evaluation of reverse phase liquid chromatography/mass spectrometry for estimation of n-octanol/water partition coefficients for organic chemicals. Chemosphere 14(10), 1551-1560. 

R.E. Sawicki, E. and Krost, K./ Estimation of N-nitroso-dimethylamine Levels in Ambient Air by Capillary Gas-Liquid Chromatography/ Mass Spectrometry, Anal. Lett. 1976, 9(6) 579-594. 

Burkhard, L. R, D. W. Kuehl, and G. D. Veith, Evaluation of Reverse Phase Liquid Chromatography / Mass-Spectrometry for Estimation of V-Octanol / Water Partition Coefficients. Chemosphere, 1985 14, 1551-1560. 

Blom KF, Larsen BS, McEwen CN, Determining affinity-selected ligands and estimating binding affinities by online size exclusion chromatography/liquid chromatography-mass spectrometry, J. Comb. Chem., 1, 82-90, 1999. 

Yu, C. et al., A rapid method for quantitatively estimating metabolites in human plasma in the absence of synthetic standards using a combination of liquid chromatography/ mass spectrometry and radiometric detection, Rapid Commun. Mass Spectrom., 21(4), 497, 2007. 

Valaskovic, G.A. et al., Ultra-low flow nanospray for the normalization of conventional liquid chromatography/mass spectrometry through equimolar response Standard-free quantitative estimation of metabolite levels in drug discovery, Rapid Commun. Mass Spectrom., 20, 1087, 2006. 

Fig. 9.2 Relative concentrations of P450 in human liver microsomes. a P450s in 60 liver samples were estimated using immunochemical methods (electrophoresis/immunoblot-ting) [52]. Because of cross-reactivity, the individual P450s in subfamilies are not distinguished. The unknown fraction is the difference between the sum of the immunochemi-cally determined forms and the total amount, calculated from Fe -CO versus Fe " difference spectroscopy [53]. b-d Estimates were made using liquid chromatography-mass spectrometry (LC-MS) proteomic analysis with heavy-atom peptides, b Results of an analysis of 50 pooled human liver samples (XenoTech, HLM610 preparation) [54]. c Results reported in the same reference as Part 5 [54] as means from analysis often individual human samples, d Analysis of a pooled set of 23 human liver samples by another laboratory [55]...

Initially, simple methods such as ultraviolet-visible (UV-Vis), fluorescence or infrared (IR) spectroscopy were proposed in order to estimate the total amount of antioxidants in various food samples. However, coupled methods such as gas chromatography-mass spectrometry (GC-MS), high performance liquid chromatography with ultraviolet-visible (HPLC-UV-Vis) or nuclear magnetic resonance detector (HPLC-NMR) and liquid chromatography-mass spectrometry (LC-MS) are employed more to quantify individual tocols or carotens from various corn-based food samples. In this chapter all these methods of analysis will be briefly described. 

C. Soler, K. J. James, and Y. Pico. Capabilities of Different Liquid Chromatography Tandem Mass Spectrometry Systems in Determining Pesticide Residues in Food Application to Estimate Their Daily Intake. J. Chromatogr., A1157(2007) 73-84. 

F. Laborda, J. Medrano and J. R. Castillo, Estimation of the quantification uncertainty from flow injection and liquid chromatography transient signals in inductively coupled plasma mass spectrometry, Spectrochim. Acta, Part B, 59(6), 2004, 857-870. 

Herron, W. J. Eadie, J. Penman, A. D. 1995. Estimation of ranolazine and eleven phase I metabolites in human plasma by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry with selected-ion monitoring. J. Chromatogr. A, 712,55-60. 

Further study will entail concentration and purification of the important intact complexes and subunits using recycling GPC and high pressure liquid chromatography, followed by detailed chemical characterization of the ligands using gas chromatography-mass spectrometry and estimation of Ni stability constants. 

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