|Hyphenated Techniques as Modern Detection Systems in Ion Chromatography|
K.M. Ruth, A. Wille, S. Czyborra and J. Kleimann
Historically ion chromatography (IC) using conductivity detection has been successfully used for the analysis of ionic (e.g., anions and cations) and polar substances (e.g., organic acids or sugars). However, due to current toxicity concerns, analyses in complex matrices require improved sensitivities and selectivities.
|Stable Isotope Dilution Analysis of Organic Pollutants Using LC-MS/MS (QqQ) and Isotope Pattern Deconvolution|
A. Castillo, E. Gracia-Lor, A.F. Roig-Navarro, P. Rodriguez-Gonzalez, J.V. Sancho and J.I. García Alonso
LC-MS/MS equipped with a triple quadrupole (QqQ) in the Selected Reaction Monitoring (SRM) has been widely accepted as the main tool in the identification, structural characterization and quantitative determination of semi-polar and polar organic pollutants in food and environmental samples. However there are limitations with these techniques.
|LC-MS Approaches to Profiling of Non-Radiolabelled Metabolites in Response to Recent Regulatory Changes|
Richard Clayton, Caroline Anderson, Brian Morrison and Lindsay Corfield
Following publication of the FDA MIST guidelines and revision of ICH M3, there is increasing interest in obtaining metabolic profiling data at an early stage in the development of a drug. This has led to a requirement to estimate the relative abundance of metabolites in samples prior to the synthesis of the radiolabelled compound and from a wider range of studies.
|Basic amino acids profiling during hepatic tumorigenesis by hydrophilic interaction liquid chromatography tandem mass spectrometry (HILIC-MS/MS)|
O. D’Apolito (1), D. Garofalo (1), D. Paris (2), D. Melck (2), R. Calemma (3), F. Izzo (3), G. Palmieri (2), A. Motta (2) and G. Corso (1)
This study is aimed to characterize basic aminoacids profiles from liver tissues of primary hepatocarcinoma (HCC) and metastases from colorectalcarcinomas (MET), and from adjacent cirrhotic related hepatitis-C-virus (CIRR) and non-cirrhotic normal liver (NT). Arginine levels in MET are significantly higher (P<0.05) compared to NT, CIRR and HCC. Although our preliminary data should be validated, profiling of basic aminoacids could allow a better classification of liver malignancies in humans.
|A Novel Approach to Internal Standardization in LC/MS/MS Analysis; Sensitive LC/MS/MS Analysis of Gentamicin|
Bruce Babson, Noel Henderson and Nicholas Chestara
A novel approach to internal standardization in LC/MS/MS is demonstrated. Gentamicin, a multi-component aminoglycoside, is derivatized with propyl-d7 chloroformate making the internal standard. Gentamicin components in the samples are derivatized with non-labeled propyl chloroformate making them analogous to the internal standard. Additional benefits of the derivatization are increased hydrophobicity and excellent MS/MS fragmentation.
|A novel method for coupling capillary columns|
Wil van Egmond, Daniela Peroni,
Using a proprietary, low-melting, deactivated glass we have developed a novel instant Meltfit™ connection. Reliable connectors are made in-situ in less than a minute.
|Single stage reversed-phase liquid chromatography-mass spectrometry for the characterization of triglyceride positional isomers.|
Haslina Hasan, Brendan J Keely and Julie Wilson
The high level of selectivity afforded by RP-HPLC in combination with CID allowed recognition of eight groups of TAG positional isomers. Development of UPLC approach has reduced the run time by half while maintaining separation. The improved method combined with principal components analysis was used to assess the extent of variation of major TAGs in subcutaneous and intermuscular pork fat from four different locations of adipose tissues.
|Five noncovalent peptidic ligands show different affinity rankings in solution and gas phase|
Andrey Dyachenko , Michael Goldflam , Marta Vilaseca , Ernest Giralt
Stability of noncovalent complexes of VEGF protein with 5 peptidic ligands is studied. Experiments were conducted in solution (NMR CSP, ITC) and in gas phase (CID TOF MS). Each ligand differs from others in chirality of one amino acid. It was shown, that trend of stability of the studied noncovalent complexes is reversed in the gas phase relatively to the solution. An explanation of this behavior is presented.
|Achieving Great Science : Bringing Together Physical Measurements and Chemical Analysis|
Michael Boruta, Michel Hachey
Many problems in analytical spectroscopy require insight from several different techniques to adequately resolve the problem. A common difficulty with using several techniques is often the ability to manage the various data types and making the data available for review, analysis and reporting.
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