Liquid chromatography-nuclear magnetic detection

We can detect and identify any chemical substance using a range of different techniques. Specialised instruments have been developed to carry out tests, such as gas-liquid chromatography, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. The instruments used are often very sensitive, so chemical substances can be detected at very low concentrations. [Pg.444]

Methods in the analysis of drug impurities (e.g., ultraviolet, UV Fourier transform infrared, FT-IR nuclear magnetic resonance, NMR mass spectrometry, MS) are used to separate, identify, and quantify impurities, as well as establish their structure. Currently the most efficient methods seem to be combined techniques such as GC-MS, LC-MS, liquid chromatography-diode-array detection-mass spectrometry (LC-DAD-MS), LC-NMR, LC-DAD-NMR-MS, etc. [18-20]. [Pg.189]

FID = flame ionization detection GC = gas chromatography HPLC = high performance liquid chromatography ITMS = ion trap mass spectrometry MS = mass spectrometry PNMR = proton nuclear magnetic resonance TLC = thin-layer chromatography... [Pg.134]

Queiroz, E.F. et al., On-line identification of the antifungal constituents of Erythrina vogelii by liquid chromatography with tandem mass spectrometry, ultraviolet absorbance detection and nuclear magnetic resonance spectrometry combined with liquid chromatographic micro-fractionation, J. Chromatogr. A, 972, 123, 2002. [Pg.36]

Wolfender, J.-L., Ndjoko, K., and Hostettmann, K., Liquid chromatography with ultraviolet absorbance-mass spectrometric detection and with nuclear magnetic resonance spectrometry a powerful combination for the on-line structural investigation of plant metabolites, J. Chromatogr. A, 1000, 437, 2003. [Pg.124]

The system relies upon preliminary fractionation of the microbial crude extract by dualmode countercurrent chromatography coupled with photodiode array detection (PDA). The ultraviolet-visible (UV-Vis) spectra and liquid chromatography-mass spectrometry (LC-MS) of biologically active peaks are used for identification. Confirmation of compound identity is accomplished by nuclear magnetic resonance (NMR). Use of an integrated system countercurrent chromatography (CCC) separation, PDA detection, and LC-MS rapidly provided profiles and structural information extremely useful for metabolite identification (dereplication, Figure 14.1). [Pg.191]

Abbreviations DCM, dichloromethane DIC, 1,3-diisopropylcarbodiimide DIEA, diiso-propylethylamine DMAP, 4-dimethylaminopyridine DMF, IVJV-dimethylformamide ELSD, evaporative light scattering detection HOBt, hydroxybenzotriazole IR, infrared LC/MS, high-pressure liquid chromatography/mass spectrometry NMM, V-methylmorpho-line NMR, nuclear magnetic resonance PyBop, benzotriazol-l-yloxytripyrrolidino-phosphonium hexafluorophosphate SAR, structure-activity relationship TFP, tetrafluorophenol THF, tetrahydrofuran. [Pg.151]

Notes LOD, limit of detection MeOH, methanol EtOH, ethanol ACN, acetonitrile EtAC, ethyl acetate SPE, solid phase extraction HLB (hydrophilic lipophilic balanced) TFA, trifluoroacetic acid GC, gas chromatography TMS, trimethylsilyl MS, mass spectrometry HPLC, high-performance liquid chromatography DAD, diode array detector NMR, nuclear magnetic resonance ESI, electrospray ionization APCI, atmospheric pressure chemical ionization CE, capillary electrophoresis ECD, electrochemical detector CD, conductivity detector TLC, thin layer chromatography PDA, photodiode array detector. [Pg.65]

Mass spectrometry (MS), infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy with their numerous applications are the main instrumental techniques for the detection and identification of CWC-related chemicals. During the last few years, however, less laborious techniques such as liquid chromatography (LC) and capillary electrophoresis (CE) have become attractive for the analysis of water samples and extracts where sample preparation is either not required or is relatively simple. [Pg.163]