Liquid chromatography–mass spectrometry and liquid chromatography–tandem mass spectrometry determination of N-methylpyrrolidinone in riverine biofilms

A rugged procedure utilizing reversed-phase liquid chromatography with positive-ion electrospray ionization mass spectrometry (LC–MS) along with tandem MS is described for the quantification and confirmation of N-methylpyrrolidinone (NMP) in methanolic extracts of riverine biofilm. The LC–MS method provided a 100-fold improvement in detection limits (2 ng g−1 with a repeatability of 80–95% based on triplicate analyses) compared to a conventional LC–UV detection procedure and was applicable to quantitative analysis of biofilm samples with little or no clean up. Under low-energy collision induced dissociation (CID) conditions (17 V, laboratory frame of reference, with argon as the collision gas), two product-ions of the [M+H]+ ion were formed at m/z 69 [MH-CH3NH2]+ and m/z 58 [MH-CH3NCH]+ with relative abundances of 30% and 5%, respectively. These CID transitions were used to demonstrate that biofilm uptake of a photocatalytically-generated mixture of NMP was rapid once acclimation was achieved.