The LC-MS/MS analysis of pharmaceutical compounds in water and sediments upon positive ESI

A number of pharmaceutical compounds can be determined in water or sediment samples in our laboratory. For the analysis of water samples, we use a combination of large-volume injections with highly sensitive MRM acquisition. The large-volume injections save time on sample preparation and provide a solution for recovery-related problems sometimes observed using SPE preconcentration techniques. For improving the accuracy of results, the samples are spiked with available isotopically labeled internal standards.

 For the analysis of pharmaceutical compounds in sediments, the samples are extracted with organic solvents using an accelerated solvent extractor (ASE, Dionex).

Instrument: QTRAP 6500+ mass spectrometer (Sciex) coupled with Nexera binary UPLC (Shimadzu). The mass spectrometer was operated in positive ESI scheduled MRM mode. Chromatographic separations were carried out using the Luna Omega Polar-C18 column (2.1×150 mm, 3 µm particle size, Phenomenex) using a linear gradient of ACN/water (with 0.1% formic acid and 5 mM ammonium formate). The instrument was controlled and data were analyzed using Analyst and MultiQuant software respectively (Sciex).