Simultaneous determination of N-hydroxymethyl-N-methylformamide, N-methylformamide and N-acetyl-S-(N-methylcarbamoyl)cystein in urine samples from workers exposed to N,N-dimethylformamide by liquid chromatography–tandem mass spectrometry

Ionic Liquids for the Electroreductive Radical Cyclization of Unsaturated Bromo Derivatives Catalyzed by Nickel(II) Complexes

“…Most electrosynthetic processes have been performed in aprotic organic solvents, such as N,Ndimethylformamide (DMF) or acetonitrile, because those processes need a polar and generally aprotic solvent; however, they can be toxic or present some toxicity, which make them unattractive media. 1,2 Due to an increasingly "green"-conscious industrial community, the search for non-toxic fluids is still desirable. Room-temperature ionic liquids (RTILs) can be an attractive alternative to volatile organic solvents, in order to conduct more eco-friendly and sustainable chemical processes.…”

A survey of liquid chromatographic–mass spectrometric analysis of mercapturic acid biomarkers in occupational and environmental exposure monitoring

“…In the methods reviewed, a variety of sample preparation techniques are described with the simplest being dilution and filtration through 0.2 μ cellulose medium followed by direct injection [12]. Other techniques use sample concentration with re-suspension in methanol or acetonitrile, or protein precipitation by acidification and centrifugation prior to analysis [9, 16, 19, 21]. Most methods utilize manual solid phase extraction (SPE), while four methods utilize online sample extraction with column switching, where urine is passed through a trap using an online multiple valve [5–8].…”

Mercapturic acids: recent advances in their determination by liquid chromatography/mass spectrometry and their use in toxicant metabolism studies and in occupational and environmental exposure studies

“…Initial acidification of urine is common to some sample preparation procedures, and in S -phenylmercapturic acid analysis samples were so treated (Maestri et al, 2005, Paci et al, 2007, Sterz et al, 2010). Other techniques use sample concentration with re-suspension in methanol or acetonitrile, or protein precipitation by acidification and centrifugation prior to analysis (Wu et al, 2012; Sterz et al, 2012; Sohn et al, 2005; Alwis et al, 2012). Most methods use a form of solid phase extraction (SPE) for sample preparation and clean-up.…”