Development, validation, and application of a novel LC-MS/MS trace analysis method for the simultaneous quantification of seven iodinated X-ray contrast media and three artificial sweeteners in surface, ground, and drinking water

Abstract

A new method for the simultaneous determination of iodated X-ray contrast media (ICM) and artificial sweeteners (AS) by liquid chromatography-tandem mass spectrometry (LC-MS/MS) operated in positive and negative ionization switching mode was developed. The method was validated for surface, ground, and drinking water samples. In order to gain higher sensitivities, a 10-fold sample enrichment step using a Genevac EZ-2 plus centrifugal vacuum evaporator that provided excellent recoveries (90 ± 6 %) was selected for sample preparation. Limits of quantification below 10 ng/L were obtained for all compounds. Furthermore, sample preparation recoveries and matrix effects were investigated thoroughly for all matrix types. Considerable matrix effects were observed in surface water and could be compensated by the use of four stable isotope-labeled internal standards. Due to their persistence, fractions of diatrizoic acid, iopamidol, and acesulfame could pass the whole drinking water production process and were observed also in drinking water. To monitor the fate and occurrence of these compounds, the validated method was applied to samples from different stages of the drinking water production process of the Industrial Works of Basel (IWB). Diatrizoic acid was found as the most persistent compound which was eliminated by just 40 % during the whole drinking water treatment process, followed by iopamidol (80 % elimination) and acesulfame (85 % elimination). All other compounds were completely restrained and/or degraded by the soil and thus were not detected in groundwater. Additionally, a direct injection method without sample preparation achieving 3-20 ng/L limits of quantification was compared to the developed method.

Artificial Sweeteners Reveal Septic System Effluent in Rural Groundwater

“…In groundwaters, previous studies have shown that ACE is more persistent than SUC (Scheurer et al, 2009; Robertson et al, 2013). Acesulfame also survives water treatment processes and can subsequently end up in the municipal water supply for communities sourcing their raw municipal water from surface waters and groundwaters containing wastewater (Buerge et al, 2009; Scheurer et al, 2010; Prasse et al, 2011; Gan et al, 2013; Nödler et al, 2013; Spoelstra et al, 2013; Ens et al, 2014; Scheurer et al, 2014). Aspartame, another commonly used artificial sweetener, is metabolized completely within the body (Renwick, 1986) and is therefore not found in wastewater‐affected environmental samples (Scheurer et al, 2009; Lange et al, 2012).…”

Mechanistic insight into the dramatic improvement of probucol dissolution in neutral solutions by solid dispersion in Eudragit E PO with saccharin

“…This change was attributed to the electrostatic intermolecular interaction of the carboxyl group of acidic MFA with the tertiary amino group of basic EPO. SAC is an acidic compound, and the amidic proton has a p Ka of around 2, which makes it easy to deprotonate,[35,36] whereas the tertiary amino group in EPO is readily protonated because the p Ka of its conjugate base is 10 [37]. The interaction mode of a crystalline acid‐base complex is usually described by Δp Ka (p Ka of base – p Ka of acid); an ionic bond is favoured when Δp Ka > 3 [38–40].…”

Rapid determination of X-ray contrast agent iomeprol in human plasma by on-line solid-phase extraction coupled with phase optimized liquid chromatography

“…According to the literatures [26][27][28], a good recovery of nonionic, iodinated X-ray contrast media agents (including IOX, IOM, IOP, IOD, etc.) from environmental and biological samples was obtained with an off-line LiChrolut EN SPE disposable column.…”