Liquid chromatography coupled with mass spectrometry

LC-MS Liquid chromatography coupled with mass spectrometry... 

M. A. Moseley, L. J. Deterding, K. B. Tomer, and J. W. Jorgenson. Nanoscale Packed-Capillary Liquid Chromatography Coupled with Mass Spectrometry Using a Coaxial Continuous-Flow Fast Atom Bombardment Interface. Anal. Chem., 63(1991) 1467-1473. 

As analytical and bioanalytical methods must be validated before using them for routine sample analysis and after changing method parameters (see Chapter 8), instruments such as liquid chromatography coupled with mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS/MS), which are utilized to perform the analysis, should be calibrated and qualified. In addition, an instrument s performance should be tested for suitability prior to use on practically a day-to-day basis. 

Electrochemical detection is better suited to the analysis of erythromycin and lincomycin. This method of detection has been applied for the determination of erythromycin A (139) and lincomycin (154) residues in salmon tissues. Liquid chromatography coupled with mass spectrometry is particularly suitable for confirmatory analysis of the nonvolatile macrolides and lincosamides. Typical applications of this technique are through thermospray mass spectrometry, which has been used to monitor pirlimycin in bovine milk and liver (141,142), and chemical ionization, which has been applied for identification of tilmicosin (151) in bovine muscle, and for identification of spiramycin, tylosin, tilmicosin, erythromycin, and josamycin residues in the same tissue (150). 

Suter, M. J.-F., S. Riediker, and W. Giger, Selective determination of aromatic sulfonates in landfill leachates and groundwater using microbore liquid chromatography coupled with mass spectrometry , Anal. Chem., 71, 897-904 (1999). 

LCAA LC-MS LDA Leu Lys Macrosorb long chain alkylamine spacer liquid chromatography coupled with mass spectrometry lithium diisopropylamide S-leucine S-lysine cross-linked polyacrylamide adsorbed onto kieselguhr... 

Moseley, M. A. Deterding, L. J. Tomer, K. B. Jorgenson, J. W. 1991. Nanoscale packed-capillary liquid chromatography coupled with mass spectrometry using a coaxial continuous-flow fast atom bombardment interface. Anal. Chem., 63,1467-1473. 

This reaction is run under the same conditions as described earlier and the products isolated by preparative thin-layer chromatography. The products should be analyzed for P content (which would be primarily monoacylphos-phatidylcholine and unreacted sn-l diacylphosphatidylcholine) and for optical activity. Whereas the starting rac-diacylphosphatidylcholine would exhibit no optical activity, each of the above products of the reaction should have optical activity. The liberated free fatty acid can be converted to a methyl ester form and examined by gas-liquid chromatography coupled with mass spectrometry (GC-MS). 

Methyl Esters. These long-chain acyl esters are subjected to thin-layer chromatography, colorimetric analysis, and gas-liquid chromatography, coupled with mass spectrometry, as described in Chapter 4. These assays will provide information on the ester/P molar ratio (based on starting phosphate value it should be 2.0) and on the composition and relative distribution of fatty acyl residues. 

Phospholipase A2 Action. As in the case of phosphatidylcholine, the above-mentioned phospholipases will attack only the sn-3 form of naturally occurring (as well as synthetic) phosphatidylethanolamine. The products are, of course, lysophosphatidylethanolamine (1 -6>-acyl-2-lyso-.rn-glycero-3-phosphoethanolamine) and the fatty acids (liberated from the sn-2 position). The latter can be analyzed for composition and structure, as the methyl esters, by gas-liquid chromatography coupled with mass spectrometry. Usually these acyl groups are largely the unsaturated types. 

Methyl Esters. This fraction can be examined first by its behavior on unidimensional thin-layer chromatography. In a solvent system of petroleum ether (30-60°)-diethyl ether-glacial acetic acid (90 10 1, v/v) and using silica gel G (250 p-m) plates, there was only a single spot at Rf 0.65-0.67. This compared exactly with a standard synthetic methyl palmitate. As described in Chapter 4, the chemical nature of the methyl esters can be obtained by analysis on gas-liquid chromatography coupled with mass spectrometry. 

Draisci, R., Giannetti, L., Lucentini, L., Eerretti, E., Palleschi, L., and Marchiafava, C. 1998. Direct identification of yessotoxin in shellfish by liquid chromatography coupled with mass spectrometry and tandem mass spectrometry. Rapid Commun Mass Spectrom 12, 1291—1296. 

GC-FID gas chromatography with flame ionization detector, HPLC-UV high performance liquid chromatography with UV detector, LC-MS liquid chromatography coupled with mass spectrometry, GC-FPD gas chromatography with flame photometric detector... 

Verpoorte, R. Niessen, W.M.A. Liquid chromatography coupled with mass spectrometry in the analysis of alkaloids. Ph)dochem. Anal. 1994, 5, 217-232. 

Through the use of liquid chromatography coupled with mass spectrometry (LC-MS), informahon on drug exposure is now routinely obtained at stages in drug discovery that were previously not thought possible. This capability has had a dramatic impact on the process of lead ophmizahon, and ultimately. 

Jeannot, R. and Sauvard, E., High performance liquid chromatography coupled with mass spectrometry applied to analyses of pesticides in water, Analusis, 27, 271-280, 1999. 

Liquid chromatography coupled with mass spectrometry (LC-MS) has been applied in the determination of BPA, OP, and NP in the environment. The advantage of this analytical method is the capability of directly determining nonvolatile or polar compounds by using ESI or atmospheric pressure chemical ionization (APCI) techniques as an interface between LC and... 

Goto, H., Igarashi, T., Yamamoto, M., Yasuda, M., Sekiguchi, R., Watai, M., Tanno, K., and Yasumoto, T., Quantitative determination of marine toxins associated with diarrhetic shellfish poisoning by liquid chromatography coupled with mass spectrometry. J. Chromatogr. A, 907, 181, 2001. 

Paz, B. et al.. Characterization of okadaic acid related toxins by liquid chromatography coupled with mass spectrometry, Toxicon, 50, 225, 2007. 

Liquid chromatography, coupled with mass spectrometry and tandem mass spectrometry (LC-MS/MS), is a universal technique for determining toxins in food. The first multiple reaction monitoring (MRM) method for polyether marine toxins was used for the determination of DSP toxins and this technique has been successfully applied to the simultaneous determination of various groups of polyether toxins in shellfish (Draisci et al., 1998, 1999). MRM involves the selection of a precursor ion and its product ion from CID fragmentations and it is highly selective. For azaspiracids, the first validated LC-MS/MS method was developed for the determination of AZAl... 

Yang M, Sun J, Lu Z, Chen GT, Guan SH, Liu X, Jiang BH, Ye M, Guo DA. Phytochemical analysis of traditional Chinese medicines (TCM) using liquid chromatography coupled with mass spectrometry. J Chromatogr A 2009 1216 2045-2062. 

Lee, S., Eom, H.-S., Yoo, M., Cho, Y, Shin, D. (2011). Determination of biogenic amines in Cheonggukjang using ultra high pressure liquid chromatography coupled with mass spectrometry. Food Science and Biotechnology, 20, 123-129. http //dx.doi.org/ 10.1007/S10068-011-0017-6. 

Toshimasa, T. 2008. Determination of methods for biologically active compounds by ultra-performance liquid chromatography coupled with mass spectrometry Application to the analyses of pharmaceuticals, foods, plants, environments, metabonomics, and metabolomics. J. Chromatogr. Sci. 46 233-247. 

---