Magda Caban

Simultaneous analysis of non-steroidal anti-inflammatory drugs and estrogenic hormones in water and wastewater samples using gas chromatography-mass spectrometry and gas chromatography with electron capture detection

Non-steroidal anti-inflammatory drugs are the group of pharmaceuticals that is most often found in the environment, whereas estrogenic hormones are considered to be potent endocrine disruptors. However, the fate and persistence of these compounds in the environment are still unclear. In this study we propose two approaches for determining these compounds in environmental water samples: GC-MS using time windows and operating in selected ion-monitoring mode (SIM) and, for the first time, gas chromatography with electron capture detection (GC-ECD). The identification criteria of both methods fulfilled the requirements of Directive 2002/657/EC. The use of time windows improved the sensitivity of GC-MS measurements. In GC-MS analysis the pharmaceuticals were determined as trimethylsilyl, in GC-ECD as pentafluoropropionyl derivatives. The influence of such parameters as the type of reagent, type of solvent, reaction time, reaction temperature and microwave irradiation in a household microwave oven on the efficacy of silylation was investigated. Derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and 1% trimethylchlorosilane (TMCS) in pyridine (1:1, v/v) for 30 min in 60 °C was found to be optimal. Optimization of the solid phase extraction procedure (SPE) confirmed that the application of Oasis HLB cartridges, the acidification of loading samples to pH2 and the use of methanol as eluent gave the best absolute recoveries (ARs) of the target compounds. The following ARs of all the compounds were achieved: 58.2-106.8% in influent wastewater, 77.8-103.4% in effluent wastewater and 81.2-101.9% in surface water samples. Validation of the SPE-GC-MS method enables 13 pharmaceuticals to be determined with MDLs between 3.3 and 343.6 ng/L, depending on the analytes and matrices. GC-ECD analysis enables the determination of 6 pharmaceuticals in surface water samples with MDLs between 0.7 and 5.4 ng/L. The proposed methods were successfully used for analyzing selected pharmaceuticals in wastewaters and river waters in Poland.

Matrix effects and recovery calculations in analyses of pharmaceuticals based on the determination of β-blockers and β-agonists in environmental samples.

In recent years substantial progress has been made in analytical methods for determining pharmaceutical residues in environmental samples. Although much work has attempted to establish the influence of sample matrix complexity on results through the determination of matrix effects (ME), extraction efficiency (EE) and absolute recovery of analytes (AR), comparison of these parameters is very complicated because different authors use different methods to obtain them. Moreover, there are few literature data describing the influence of aqueous matrices (tap water and waste water) on results obtained with GC-MS methods. For these reasons, the main aims of the present study were: (1) to critically review the determination of matrix effects and recovery parameters using the two most common techniques for analyzing drugs in environmental samples: gas and liquid chromatography coupled with mass spectrometry or tandem mass spectrometry (GC-MS, GC-MS/MS and LC-MS, LC-MS/MS); (2) to postulate a uniform method for determining ME, EE and AR using GC techniques; (3) to investigate the influence of different aqueous matrices on the solid-phase extraction, derivatization and final determination of drugs using GC. β-Blockers and β-agonists, drugs commonly found in the environment, were chosen as model compounds for this investigation. The values of ME, EE and AR obtained were compared with analogous (or similar) data obtained by other researchers using LC-MS measurements. All the results confirmed that GC-MS analyses are much less sensitive to the complexity of sample matrices than LC-MS, so GC-MS measurements appear to be a very good alternative to LC-MS methods of determining pharmaceutical residues in environmental samples.

Determination of β-blockers and β-agonists using gas chromatography and gas chromatography–mass spectrometry – A comparative study of the derivatization step

There is a growing demand for the rapid screening of multiple β-blockers and β-agonists in a single analytical run in clinical toxicology, antidoping control, forensic and environmental science. Although GC-MS is very often used to determine pharmaceuticals from these groups of drugs, the literature data on the derivatization and MS analysis of mixtures of these compounds is limited. This paper compares and evaluates derivatization procedures for the determination of six β-blockers (acebutolol, atenolol, metoprolol, nadolol, propranolol, pindolol) and two β-agonists (salbutamol, terbutaline) using GC techniques. Nineteen different derivatizing reagents (nine of them used for the first time with almost all the drugs) were employed in order to obtain a single derivative for each target compound with the greatest effectiveness of this reaction. Trimethylsilylation, tert-butyldimethylsilylation, acylation (e.g. trifluoroacetylation), combined trimethylsilylation and acylation, and the formation of cyclized silyl derivatives were carried out and the mass spectra (EI, 70 eV) recorded. The influence of the reaction time and temperature on these procedures was investigated. Additionally, the effects of the type of solvent and the amount of added trimethylchlorosilane (TMCS) on the silylation of the target compounds using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) were tested. Among of the five mentioned above derivatization procedures applied - trimethylsilylation was found to be the most effective for derivatizing the analytes. The best results were obtained with a 1:1 (v/v) mixture of 99% BSTFA+1% TMCS and ethyl acetate at 60 °C for 30 min. The MS data for different types of β-blocker and β-agonist derivatives is presented. The information in this paper is valuable for scientists working on the determination of β-blockers and β-agonists in biological and environmental matrices.

Bioaccumulation and analytics of pharmaceutical residues in the environment: A review

The presence of pharmaceutical residues in various environmental compartments is an issue of increasing concern. The widespread occurrence of these compounds in water and soil samples has been demonstrated in a number of analytical studies. However, the data about their concentrations in biota samples is scarce. Moreover, the trophic transfer of pharmaceuticals remains largely unexplored, despite increasing evidence of the potential bioaccumulation of those compounds. Therefore, the main aim of this review is to present an overview of the current state of data about the bioaccumulation and analytical methodologies used for the determination of pharmaceutical residues in biota samples. This work focuses on the most commonly found pharmaceuticals in the environment: antibiotics, analgesic and anti-inflammatory drugs, steroid hormones, antihypertensives and antidepressants. We do hope that the collected data will allow a better understanding of pharmaceutical pollution and the exposure of non-target organisms. However, although impressive progress has undoubtedly been made, in order to fully understand the behavior of these chemicals in the environment, there are still numerous gaps to be filled in our overall knowledge in this field.

Enhanced extraction of proteins using cholinium-based ionic liquids as phase-forming components of aqueous biphasic systems

Aqueous biphasic systems (ABS) composed of ionic liquids (ILs) are promising platforms for the extraction and purification of proteins. In this work, a series of alternative and biocompatible ABS composed of cholinium-based ILs and polypropylene glycol were investigated. The respective ternary phase diagrams, tie-lines, tie-line lengths and critical points were determined at 25°C. The extraction performance of these systems for commercial bovine serum albumin (BSA) was then evaluated. The stability of BSA at the IL-rich phase was ascertained by size exclusion high-performance liquid chromatography and Fourier transform infrared spectroscopy. Appropriate ILs lead to the complete extraction of BSA for the IL-rich phase, in a single step, while maintaining the proteins native conformation. Furthermore, to evaluate the performance of these systems when applied to real matrices, the extraction of BSA from bovine serum was additionally carried out, revealing that the complete extraction of BSA was maintained and achieved in a single step. The remarkable extraction efficiencies obtained are far superior to those observed with typical polymer-based ABS. Therefore, the proposed ABS may be envisaged as a more effective and biocompatible approach for the separation and purification of other value-added proteins.

Beta-blockers in the environment: Part I. Mobility and hydrolysis study

Beta-blockers (BB) are one of the most widely used pharmaceuticals whose presence in different environmental compartments has already been proven in concentrations of even up to a few μg L(-1). However, our knowledge of their fate in the environment is still scarce. To obtain a better understanding on the environmental behavior of three selected BB comprehensive laboratory experiments assessing their mobility and hydrolytic stability has been conducted. Propranolol, metoprolol and nadolol--the most commonly consumed and detected in environmental samples--were selected as representatives of this group of pharmaceuticals. The objectives of our research were: (i) evaluation of the sorption potential and an explanation of the sorption mechanisms of these compounds onto soil and clay mineral (kaolinite); and (ii) investigation of the hydrolytic stability of these BB according to OECD 111. This comprehensive study supports the Environmental Risk Assessment of these pharmaceuticals.

Beta-blockers in the environment: Part II. Ecotoxicity study

The increasing consumption of beta-blockers (BB) has caused their presence in the environment to become more noticeable. Even though BB are safe for human and veterinary usage, ecosystems may be exposed to these substances. In this study, three selected BB: propranolol, metoprolol and nadolol were subjected to ecotoxicity study. Ecotoxicity evaluation was based on a flexible ecotoxicological test battery including organisms, representing different trophic levels and complexity: marine bacteria (Vibrio fischeri), soil/sediment bacteria (Arthrobacter globiformis), green algae (Scenedesmus vacuolatus) and duckweed (Lemna minor). All the ecotoxicological studies were supported by instrumental analysis to measure deviation between nominal and real test concentrations. Based on toxicological data from the green algae test (S. vacuolatus) propranolol and metoprolol can be considered to be harmful to aquatic organisms. However, sorption explicitly inhibits the hazardous effects of BB, therefore the risks posed by these compounds for the environment are of minor importance.

Determination of metronidazole residues in water, sediment and fish tissue samples

Metronidazole (MNZ) is an antibacterial and antiprotozoal drug used in veterinary and human medicine. Its continual entry into the environment and its biological properties may have significant, long-term effects on the stability of ecosystems because MNZ and its metabolites possess mutagenic, carcinogenic and toxic properties. For this reason, the application of MNZ in food-producing species is prohibited in the EU, the USA and other countries. To ensure human food safety and to protect the environment, robust and reliable screening and confirmatory tests capable of the low-level detection of MNZ residues are required. The development of methods for MNZ determination in biological and environmental samples is thus an important analytical task in environmental and food science. This work focuses on the evaluation of a method for determining MNZ in water, sediment and fish tissue samples using liquid chromatography--ion trap mass spectrometry (LC-MS/MS). MNZ was extracted from waters on Strata XC cartridges using solid phase extraction (SPE), and from sediments and fish tissues by solid-liquid extraction (sediment: 15 mL 0.1 M HCl (pH=0.6), 15 min; fish tissue: 15 mL 1% CH3COOH in ACN, 1 min; drying: 5 g MgSO4(anhyd.; 30 s) with SPE purification of the extracts (from sediment: Strata XC cartridge; from fish tissue: Supelco NH2 cartridge). The optimal procedure that we developed was validated in order to confirm its reliability and sensitivity. Matrix effects (ME) were established. Absolute recoveries ranged from 89.3% to 97.2%, and the method detection limits were 3.4 ng L(-1) (water samples), 0.4 ng g(-1) (sediment samples) and 0.3 ng g(-1) (tissue samples). These methods were used to determine MNZ in surface waters, sediments and fish tissues from the Polish River Gościcina; MNZ was found in all these matrices. The highest concentrations in water, sediment and tissue were 136.2 ng L(-1), 12.0 ng g(-1) and 1.5 ng g(-1) respectively. The results confirmed that these methods are suitable for the simultaneous analysis of waters, sediments and fish tissues for the presence of MNZ.

Simultaneous determination of non-steroidal anti-inflammatory drugs and oestrogenic hormones in environmental solid samples.

Pharmaceuticals are continually being released into the environment. Because of their physical and chemical properties, many of them or their bioactive metabolites can accumulate in sediments, sludge and soils, and induce adverse effects in terrestrial organisms. However, due to the very limited methods permitting the detection of these low-level concentration compounds in such complex matrices, their concentrations in natural solids remain largely unknown. In this paper, an analytical method for the simultaneous determination of thirteen pharmaceuticals (eight non-steroidal anti-inflammatory drugs and five oestrogenic hormones) in solid matrices was developed. The proposed MAE-SPE-GC-MS(SIM) method has been successfully validated providing a linear response over a concentration range of 1(17)-1000(1200)ng/g, depending on the pharmaceuticals, with correlation coefficients above 0.991. The method detection limits were in the range of 0.3-5.7 ng/g, absolute recoveries above 50%, except estrone. The developed method was applied in the analysis of the target compounds in sediment, sludge and soils collected in Poland giving primary data on their concentrations in such matrices in Poland. The obtained results confirmed that the proposed method can be successfully used in the analysis of real environmental solid samples.

Determination of pharmaceutical residues in drinking water in Poland using a new SPE-GC-MS(SIM) method based on Speedisk extraction disks and DIMETRIS derivatization

The presence of pharmaceuticals in drinking water, even at very low concentrations, has raised concerns among stakeholders such as drinking-water regulators, governments, water suppliers and the public, with regard to the potential risks to humans. Despite this, the occurrence and the fate of pharmaceuticals in drinking waters of many countries (e.g. in Poland) remains unknown. There is a lack of sufficiently sensitive and reliable analytical methods for such analyses and a need for more in-depth hydrogeological analysis of the possible sources of drug residues in drinking water. In this paper, a multi-residual method for the simultaneous determination of seventeen human pharmaceuticals in drinking waters has been developed. Large-volume extractions using Speedisk extraction disks, and derivatization prior to GC-MS-SIM analysis using a new silylating agent DIMETRIS were applied. The method detection limits (MDLs) ranged from 0.9 to 5.7ng/L and the absolute recoveries of the target compounds were above 80% for most analytes. The developed method was successfully applied in the analysis of the target compounds in drinking water collected in Gdansk (Poland), and of the 17 pharmaceuticals, 6 compounds were detected at least once. During the investigation, the geomorphology of the site region was taken into account, possible sources of pharmaceuticals in the analysed drinking water samples were investigated, and the presence of the drugs in ground and surface waters, raw and treated drinking waters was determined. Concentrations were also compared with those observed in other countries. As a result, this study has not only developed a new analytical method for determining pharmaceuticals in drinking waters as well as rendering missing information for Poland (a country with one of the highest consumptions of pharmaceuticals in Europe), but it also presents a modelled in-depth hydrogeological analysis of the real sources of drugs in drinking waters.