Publications by authors named "P Perez-Hurtado"

Rationale: The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses.

View Article and Find Full Text PDF

The method of phasing broadband Fourier transform ion cyclotron resonance (FT-ICR) spectra allows plotting the spectra in the absorption-mode; this new approach significantly improves the quality of the data at no extra cost. Herein, an internal calibration method for calculating the phase function has been developed and successfully applied to the top-down spectra of modified proteins, where the peak intensities vary by 100×. The result shows that the use of absorption-mode spectra allows more peaks to be discerned within the recorded data, and this can reveal much greater information about the protein and modifications under investigation.

View Article and Find Full Text PDF

Two polymeric excipients, typically used in enabling drug delivery approaches, are Gelucire 44/14 (a product of Gattefosse s.a, St Priest, France) and polysorbate 80; these are known to improve solubility of poorly water-soluble drugs and, hence, increase their effective bioavailability. In addition to the use of Gelucire 44/14 and polysorbate 80 as excipients in drugs, they are also widely used as cosmetic and food additives.

View Article and Find Full Text PDF

An isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was successfully developed and applied for analysis of 15 pharmaceuticals and 2 pharmaceutically active metabolites in fish tissues. This method relied on electrospray ionization (ESI), for which the influence of sample matrix on analyte ionization efficiencies remains a persistent challenge to environmental analysis. Statistically derived method detection limits (MDLs) for most analytes ranged from 1 to 10 ng/g, independent of sample matrix, and were as low as 0.

View Article and Find Full Text PDF

It has been known for almost 40 years that phase correction of Fourier transform ion cyclotron resonance (FTICR) data can generate an absorption-mode spectrum with much improved peak shape compared to the conventional magnitude-mode. However, research on phasing has been slow due to the complexity of the phase-wrapping problem. Recently, the method for phasing a broadband FTICR spectrum has been solved in the MS community which will surely resurrect this old topic.

View Article and Find Full Text PDF