Metabonomic Profiling of Chicken Eggs during Storage Using High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry.

Metabonomic techniques have been used to discover subtle differences in the small-molecule profiles of chicken eggs, which could help to combat fraud within the egg industry. High-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-Q-ToF-MS) was used to obtain profiles of the small molecules present in the yolks of chicken eggs stored for different lengths of time. Statistical analysis, including the use of XCMS Online and further exploratory statistics, was able to uncover differences in the abundances of several of the small molecules found in these egg yolks.

Artificial neural network modelling of pharmaceutical residue retention times in wastewater extracts using gradient liquid chromatography-high resolution mass spectrometry data.

The modelling and prediction of reversed-phase chromatographic retention time (tR) under gradient elution conditions for 166 pharmaceuticals in wastewater extracts is presented using artificial neural networks for the first time. Radial basis function, multilayer perceptron and generalised regression neural networks were investigated and a comparison of their predictive ability for model solutions discussed. For real world application, the effect of matrix complexity on tR measurements is presented.

The utility of porous graphitic carbon as a stationary phase in proteomics workflows: two-dimensional chromatography of complex peptide samples.

We present the first investigation into the utility of porous graphitic carbon (PGC) as a stationary phase in proteomic workflows involving complex samples. PGC offers chemical and physical robustness and is capable of withstanding extremes of pH and higher temperatures than traditional stationary phases, without the likelihood of catastrophic failure. In addition, unlike separations driven by ion exchange mechanisms, there is no requirement for high levels of non-volatile salts such as potassium chloride in the elution buffers, which must be removed prior to LC-MS analysis.

High temperature-ultra performance liquid chromatography-mass spectrometry for the metabonomic analysis of Zucker rat urine.

The applicability and potential of using elevated temperatures and sub 2-microm porous particles in chromatography for metabonomics/metabolomics was investigated using, for the first time, solvent temperatures higher than the boiling point of water (up to 180 degrees C) and thermal gradients to reduce the use of organic solvents. Ultra performance liquid chromatography, combined with mass spectrometry, was investigated for the global metabolite profiling of the plasma and urine of normal and Zucker (fa/fa) obese rats (a well established disease animal model). "Isobaric" high temperature chromatography, where the temperature and flow rate follow a gradient program, was developed and evaluated against a conventional organic solvent gradient.