In the present study, a multi-residue method based on a bag-solid phase extraction (bag-SPE) technique was evaluated for determination of 10 pharmaceuticals in surface water close to the effluent of a sewage treatment plant (STP) and along a coastal gradient from a STP effluent.

The 10 compounds selected were caffeine, atenolol, metoprolol, oxazepam, carbamazepine, ketoprofen, naproxen, ibuprofen, diclofenac and gemfibrozil. All analyses were performed using ultra-performance liquid chromatography (UPLC) combined with quadrupole time-of-flight (QTOF) mass spectrometry. The detection limits (LOD) ranged from 1.0 to 13 ng L⁻¹. The method showed linear concentration ranges from 25 to 800 ng L⁻¹ with regression coefficients (R²) better than 0.9801. The recoveries of the selected analytes ranged from 11 to 65% with relative standard deviations (RSD) of <16% and inter-day variations of less than 18%. Isotopically labeled surrogate standards were used to compensate for sampling losses and matrix effects.

Four of the selected 10 pharmaceuticals (caffeine, metoprolol, oxazepam and carbamazepine) were quantified, at concentrations ranging from 4 to 210 ng L⁻¹.

Polar organic compounds (POCs) are chemicals with polar functional groups in their structure. The functional groups make the compounds hydrophilic and less prone to partition with biota. However, the knowledge of their fate is limited due to difficulties associated with their measurements. Although, the persistence of POCs in the environment is generally low, they are considered to be semi-persistent compounds due to their continuous introduction to the environment via wastewater. Studies have shown that complex mixtures of POCs of different classes may have synergistic toxic effects on biota at environmental concentration levels. Therefore, it is important to develop analytical methods in order to establish the occurrence and fate of POCs in aquatic environments.

In Study I, a positive correlation between the sorption of a novel poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC) material and the theoretical logarithmic dissociation partition coefficient (Log D) for seven POCs was observed. The PEVAC material showed an enhanced sorption of the POCs compared to the silicone material. Study II, demonstrated that the PEVAC sampler assess the freely dissolved concentration of POCs in aquatic environments. The results showed that the PEVAC polymer is an attractive alternative to silicone for mimicing the biological uptake of POCs in aquatic environments. Additionally, Study II showed that total extraction is appropriate for determination of the freely dissolved concentration of uncharged POCs with Log K_OW < 2.67 in natural water.

In study III, a novel bag-solid phase extraction (bag-SPE) technique was compared to a conventional SPE-technique. Despite that the extraction efficiencies for POCs in wastewater were lower using the bag-SPE method, the two methods showed similar detection limits due to the lower ion-suppression experienced with the bag-SPE.

In study IV the bag-SPE method was further developed with the aim of lowering the detection limits for POCs. Detection limits (LOD) below 13 ng/L showed that the bag-SPE method was suitable for determination of POCs in surface sea water.

This study provides a basis for a new and straightforward method for LC/MS/MS-based screening of N-terminal protein adducts. This procedure is denoted the “FIRE procedure” as fluorescein isothiocyanate (FITC) gave superior sensitivity by LC/MS/MS when measuring adducts (R) of electrophilic compounds with a modified Edman procedure. The principles of the FIRE-procedure are that adducts to N-terminal amino acids selectively are detached and measured from of proteins after derivatisation by isothiocyanate Edman reagents. In this study, FITC, 4-N,N-dimethylaminoazobenzene 4′-isothiocyanate (DABITC) and 4-dimethylamino-1-naphthyl isothiocyanate (DNITC) were used to synthesize thiohydantoin analytes from valine and N-methylvaline. The sensitivity by LC/MS/MS was enhanced by up to three orders of magnitude as compared to phenyl isothiocyanate and higher as compared to pentafluorophenyl isothiocyanate. The FITC reagent will enable measurements of low background adduct levels. Synthesized analytes were characterised with, for example, ¹H NMR, ¹³C NMR, LC/MS/MS, and UV.

Amino acids are the fundamental building blocks of proteins that are required for the initiation of living organism, therefore they are key compounds in the origin of life quest. The abiotic production of amino acids within ultramafic-hosted hydrothermal systems was suggested a few decades ago and is strongly supported by thermodynamic data and experimental work. However, field data were clearly lacking and thus investigation of amino acids in fluids from ultramafic-hosted hydrothermal systems was of major importance. Even though amino acids analysis have been carried out routinely for several decades in various field of application, none of the currently available methods appeared suitable for our purpose because of the complexity of the hydrothermal fluids matrix (salts, minerals, gases) and the extremely low concentrations of amino acids that were expected. We took up the challenge and here we describe a method to detect underivatized amino acids down to the sub-ppb level in aqueous matrix by ion-pairing reverse-phase Ultra-high Performance Liquid Chromatography - Electrospray Ionisation - Quadrupole Time of Flight - Mass Spectrometry (UPLC-ESI-QTOF-MS). Characterisation and separation of 10 chosen proteinogenic amino acids was achieved and excellent linearity in the response was obtained for all amino acids with correlation coefficient > 0.9921. This analytical method was successfully applied to natural hydrothermal fluid samples from ultramafic-hosted vents of the Mid-Atlantic Ridge region. Tryptophan and Phenylalanine were clearly evidenced in the fluids and concentrations of Leucine reached 15-55 ppt. We suggest that other amino acids are present in hydrothermal fluids but occur for the major part as metal and/or clay complexes and could not be detected using current approach. Finally, concentrations of amino acids measured in the deep seawater reference sample were in good agreement with generally accepted background level in the deep ocean.

In the present study, a multi-residue method based on a bag –solid phase extraction (bag-SPE) technique was applied to determine the occurrence of ten pharmaceuticals in surface water close to the effluent of a sewage treatment plant (STP) and along a coastal gradient from a STP effluent.

The ten compounds selected were caffeine, atenolol, metoprolol, oxazepam, carbamazepine, ketoprofen, naproxen, ibuprofen, diclofenac and gemfibrozil, i.e. a mixture of pharmaceuticals of different therapeutic classes having logarithmic octanol/water partitioning coefficients (Log K_OW) ranging from -0.13 to 4.39.

All analyses were performed using ultra performance liquid chromatography (UPLC) combined with quadrupole time-of-flight (QToF) mass spectrometry.

The detection limit (LOD) of the pharmaceuticals in water ranged from 1.0-13 ng/L. The method showed consistent linear concentration ranges from 25-800 ng/L with regression coefficients (R²) better than 0.9801. The recoveries of the selected analytes ranged from 10.6-64.5 % with relative standard deviations (RSD) of < 16.4 % and inter-day variations of less than 17.7 %.

Although the detection limits (LOD) of the analytes were low, only four of the selected ten pharmaceuticals (caffeine, metoprolol, oxazepam and carbamazepine) showed concentrations in surface water higher than the detection levels. The concentrations of the four pharmaceuticals in sea water range from 4-210 ng/L.