Comparison of different water-miscible solvents for the preparation of plasma and urine samples in metabolic profiling studies

Abstract

This version is available at https://strathprints.strath.ac.uk/7602/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the AbstractThe Lowry method and a capillary electrophoresis method were used to analyse protein residues in the supernatant after solvent deproteination of plasma. Acetonitrile and acetone were much more effective than methanol and ethanol at reducing the levels of proteins in plasma. The ability of different solvents to decrease levels of phospholipids in plasma samples was assessed using electrospray ionisation mass spectrometry (MS). Phospholipid signals can obscure differences between samples in general metabolite profiling (i.e. non-target compound) studies. Acetonitrile was much more effective than methanol in reducing the MS signal due to phospholipids in plasma which is a consequence of the poor solubility of phospholipids in acetonitrile. The capability of the solvents at reducing salts in urine samples was also studied by using an amperometric method. Using this approach little difference was detected between methanol, ethanol, acetonitrile and acetone in their ability to desalt urine samples.

Validation of a LC-MS/MS Method for Quantifying Urinary Nicotine, Six Nicotine Metabolites and the Minor Tobacco Alkaloids—Anatabine and Anabasine—in Smokers' Urine

“…As a precipitating agent, acetone and acetonitrile are more effective in removing protein than is methanol [25]. Although the effectiveness of removing protein and salt by acetonitrile or acetone is similar [25], acetone may be more effective in removing phospholipids because most human endogenous phospholipids are insoluble in acetone, and acetone is sometimes used in harvesting phospholipids for quantification in body fluids [26]–[29].…”

“…Although the effectiveness of removing protein and salt by acetonitrile or acetone is similar [25], acetone may be more effective in removing phospholipids because most human endogenous phospholipids are insoluble in acetone, and acetone is sometimes used in harvesting phospholipids for quantification in body fluids [26]–[29]. Removal of phospholipids, proteins, and salts is beneficial in several ways.…”

Determination of rosiglitazone and metformin in human serum by CE‐ESI‐MS

“…The best results, with focus on the rosiglitazone recovery as a minor component, were obtained for acetonitrile at a ratio of 1:2 as summarized in Table 2. Acetonitrile has a higher dielectric constant and lower viscosity than methanol, which plays significant role in the process of protein elimination 60. Measurements of serum samples met a few difficulties concerning the reproducibility, shape of peaks, and time of analysis due to the residue of proteins presented in the serum, which adsorbed on the capillary wall.…”

Identification and quantification of thymol metabolites in plasma, liver and duodenal wall of broiler chickens using UHPLC‐ESI‐QTOF‐MS

“…Only 500 μL of supernatant was taken and loaded on the cartridge followed by rinsing twice with 500 μL of acetonitrile-methanol (80:20). Owing to the fact that phospholipids are soluble in methanol (Alzweiri, Watson, Robertson, Sills, & Parkinson, 2008), the higher ratio of acetonitrile was selected for elution of metabolites in SPE.…”