Determination of fifteen priority phenolic compounds in environmental samples from Andalusia (Spain) by liquid chromatography-mass spectrometry

This work describes the optimisation of a method to determinate fifteen phenolic compounds in waters, sediments and biota (green marine algae) by liquid chromatography coupled to mass spectrometry (LC-MS) with atmospheric pressure chemical ionisation (APCI) in the negative mode. The LC separations of the studied compounds and their MS parameters were optimised in order to improve selectivity and sensitivity. Separation was carried out with a C-18 column using methanol and 0.005% acid acetic as mobile phase in gradient mode. The molecular ion was selected for the quantitation in selective ion monitoring (SIM) mode. A solid-phase extraction (SPE) method was applied in order to preconcentrate the target analytes from water samples. However, extraction of the compounds from sediment and biota samples was carried out by liquid-solid extraction with methanol/water after studying the influence of other organic solvents. In addition, a clean-up step by SPE with HLB Oasis cartridges was necessary for sediments and biota. The proposed analytical methodology was validated in the target environmental matrices by the analysis of spiked blank matrix samples. Detection limits were 10-50 ng L-1 for water, 1-5 mug kg(-1) for sediments and 2.5-5 mug kg(-1) for biota samples. Good recoveries and precision values were obtained for all matrices. This methodology has been successfully applied to the analysis of incurred water, sediment and biota samples from Andalusia (Spain).