High-resolution mass spectrometry method for the detection, characterization and quantitation of pharmaceuticals in water

The presence of pharmaceuticals in drinking water is an emerging environmental concern. In most environmental testing laboratories, LC-MS/MS assays based on selected reaction monitoring are used as part of a battery of tests used to assure water quality. Although LC-MS/MS continues to be the best tool for detecting pharmaceuticals in water, the combined use of hybrid high-resolution mass spectrometry (HRMS) and ultrahigh pressure liquid chromatography (UHPLC) is starting to become a practical tool to study emerging environmental contaminants. The hybrid LTQ-orbitrap mass spectrometer is suitable for integrated quantitative and qualitative bioanalysis because of the following reasons: (1) the ability to collect full-scan HRMS spectra with scan speeds suitable for UHPLC separations, (2) routine measurement of mass with less than 5 ppm mass accuracy, (3) high mass resolving power, and (4) ability to perform on-the-fly polarity switching in the linear ion trap (LTQ). In the present work, we provide data demonstrating the application of UHPLC-LTQ-orbitrap for the detection, characterization and quantification of pharmaceuticals and their metabolites in drinking water. Copyright © 2011 John Wiley & Sons, Ltd

Interplay with other circulating and genetic factors in association to Alzheimer's type dementia

Objectives: To study the interplay between serum concentrations of homocysteine, steroid hormones and vitamins B and mutations in 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, in association to Alzheimer's type dementia (ATD). Design and methods: Case-control study including 19 individuals diagnosed with ATD and 36 healthy controls. Serum concentrations of the analytes were determined and MTHFR 1298A - C mutation was screened by PCR-RFLP. Results: Multivariable logistic regression analysis identified homocysteine (OR=1.92, P0.01), cholesterol (OR C mutation (OR=6.01, P0.04) as independent predictors of ATD. Positive interaction between homocysteine and uric acid, creatinine, urea or cortisol (P0.02) and negative interaction between homocysteine and vitamin B-12 or MTHFR 1298A - C mutation (P0.03) were observed. Conclusions: High serum concentrations of homocysteine, cholesterol and uric acid, and low concentrations of estradiol and vitamin B-12, as well as the MTHFR 1298A - C mutation are simultaneously associated to ATD. (C) 2009 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved