Occurrence and seasonal variations of 25 pharmaceutical residues in wastewater and drinking water treatment plants.

Thousands of tons of pharmaceuticals are introduced into the aqueous environment due to their incomplete elimination during treatment process in wastewater treatment plants (WWTPs) and water treatment plants (WTPs). The presence of pharmacologically active compounds in the environment is of a great interest because of their potential to cause negative effects. Furthermore, drugs can undergo different processes leading to the formation of new transformation products, which may be more toxic than the parent compound. In light of these concerns, within the research a new, rapid and sensitive analytical procedure for the determination of a wide range of pharmaceuticals from different classes using solid phase extraction (SPE) and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) technique in different water samples was developed. This methodology was applied to investigate the occurrence, removal efficiency of 25 pharmaceuticals during wastewater and drinking water treatment, and seasonal variability in the amount of selected pharmaceuticals in WWTP and WTP over a year. The most often detected analytes in water samples were carbamazepine (100 % of samples) and ibuprofen (98 % of samples), concluding that they may be considered as pollution indicators of the aqueous environment in tested area. Highly polar compound, metformin, was determined at very high concentration level of up to 8100 ng/L in analyzed water samples. Drugs concentrations were much higher in winter season, especially for non-steroidal inflammatory drugs (NSAIDs) and caffeine, probably due to the inhibited degradation related to lower temperatures and limited sunlight. Carbamazepine was found to be the most resistant drug to environmental degradation and its concentrations were at similar levels during four seasons.

Development of an extraction and purification method for the determination of multi-class pharmaceuticals and endocrine disruptors in freshwater invertebrates.

Aquatic organisms from freshwater ecosystems impacted by waste water treatment plant (WWTP) effluents are constantly exposed to constant concentrations of pharmaceuticals, endocrine disruptors and related compounds, among other anthropogenic contaminants. Macroinvertebrates inhabiting freshwater ecosystems might be useful bioindicators of exposure to contaminants, since their lives are long enough to bioaccumulate, but at the same time may integrate short-term changes in the environment. However, studies about potential bioaccumulation of emerging contaminants in these organisms are very scarce. The objectives of this study were to develop an analytical methodology for the analysis of 41 pharmaceuticals and 21 endocrine disruptors in freshwater invertebrates. In addition, bioaccumulation of these contaminants in three macroinvertebrate taxa inhabiting a waste water treatment plant -impacted river was evaluated. The method for the simultaneous extraction of both families of compounds is based on sonication, purification via removal of phospholipids, and analysis by ultra performance liquid chromatography coupled to a mass spectrometer (UPLC-MS/MS) in tandem. Recoveries for pharmaceuticals were 34-125%, and for endocrine disruptors were 48-117%. Method detection limits (MDLs) for EDCs were in the range of 0.080-2.4 ng g(-1), and for pharmaceuticals, 0.060-4.3 ng g(-1). These pollutants were detected in water samples taken downstream the waste water treatment plant effluent at concentrations up to 572 ng L(-1). Two non-esteroidal anti-inflammatory drugs, diclofenac and ibuprofen, and four endocrine disruptors - estrone, bisphenol A, TBEP, and nonylphenol - were detected in at least one macroinvertebrate taxa in concentrations up to 183 ng g(-1) (dry weight). An isobaric interference was identified during the analysis of diclofenac in Hydropsyche samples, which was successfully discriminated via accurate mass determination by TFC-LTQ Orbitrap.

Elucidation of transformation pathway of ketoprofen, ibuprofen, and furosemide in surface water and their occurrence in the aqueous environment using UHPLC-QTOF-MS.

The identification and determination of transformation products (TPs) of pharmaceuticals is essential nowadays, in order to track their fate in the aqueous environment and, thus, to estimate the actual pollution. However, this is a challenging task due to the necessity to apply high-resolution instruments enable to detect known and unknown compounds. This work presents the use of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) as a powerful tool for the identification of three selected pharmaceuticals, furosemide (FUR), ibuprofen (IBP), and ketoprofen (KET), and their TPs in various water samples. Laboratory degradation experiments were performed using xenon lamp as a source of the irradiation in order to simulate phototransformation processes which may occur in the environment. Furthermore, the photodegradation kinetics of three selected compounds were assessed in a reactor equipped with xenon lamp in river water samples. Five TPs of IBP, seven of KET, and five of FUR were identified; some of them are presented here for the first time. Accurate mass measurements and fragmentation pattern obtained during an LC-QTOF-MS analysis allowed for structure elucidation of TPs followed by the creation of transformation pathway of selected pharmaceuticals. Finally, different water samples (wastewater influent and effluent, river water, untreated and treated water) were analyzed in order to estimate the presence of parent and transformed compounds. Only KET was detected in untransformed form in considered samples. Most of the TPs of selected drugs were found at least once in all water samples. Although IBP and FUR were not present in water samples as parent compounds, their different TPs occur. A great potential of LC-QTOF-MS in the identification and structural elucidation of TPs in the environment, allowing the recognition of the fate of pharmaceuticals in the environment through the determination of transformation pathway, has been presented.

Analysis of multi-class pharmaceuticals in fish tissues by ultra-high-performance liquid chromatography tandem mass spectrometry.

A new sensitive method based on pressurized liquid extraction (PLE) and purification by gel permeation chromatography (GPC) prior to ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed for the determination in fish homogenate, liver and muscle of twenty pharmaceuticals compounds and metabolites from seven commonly used therapeutic families. An extensive matrix effect evaluation was performed in order to select the best approach when analyzing such complex matrices. Limits of detection (MDLs) for the target compounds were in the range of 0.03-0.50ng/g for fish homogenate, 0.01-0.42ng/g for fish muscle, and 0.08-0.98ng/g for fish liver. The method was applied to fish tissues of eleven fish species from four heavily impacted Mediterranean rivers. Nine compounds from five therapeutic families were measured at concentrations higher than MDLs. Highest levels were found in trout liver, with a maximum concentration of 18ng/g for carbamazepine, whereas the most ubiquitous compound was diclofenac.