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

Water-compatible magnetic imprinted nanoparticles served as solid-phase extraction sorbents for selective determination of trace 17beta-estradiol in environmental water samples by liquid chromatography

Endocrine disrupting compounds (EDCs) are a potential risk for wildlife and humans for their existence in water. The efficient extraction and clean-up steps are required before detection of low concentration levels of EDCs. In this work, a novel water-compatible magnetic molecularly imprinted nanoparticles is synthesized for the selective extraction of 17β-estradiol (E2) in environmental water samples. The preparation is carried out by introducing aldehyde groups to the surface of amino-functionalized magnetic nanoparticles through a simple one-step modification, followed by copolymerization of functional monomer gelatin and template E2 via surface imprinting technique. The gelatin with abundant active groups could not only act as functional monomer reacting with template, but also assemble covalently at the surface of magnetic nanoparticles. At the same time, gelatin would improve the water-compatibility of imprinted materials for attaining high extraction efficiency. To obtain high imprinting effect, the preparation conditions are optimized in detail using Central composite design-response surface methodology. The resultant polymers have uniform spherical shape with a shell thickness of about 8nm, stable crystalline form, and super-paramagnetic property. Meanwhile, the obtained polymers have high capacity of 12.87mgg(-1) and satisfactory selectivity to template molecule. To testify the feasibility of the magnetic imprinted polymers in sample pretreatment, a method for determination of trace E2 in environmental water samples was set up by combination of solid-phase extraction (SPE) using the prepared polymers as sorbents and HPLC for rapid isolation and determination of E2. The limit of detection of proposed method is 0.04ngmL(-1), the intra- and inter-day relative standard deviations (RSDs) are less than 4.6% and 5.7%, respectively. The recoveries of E2 from environmental water samples are in the range from 88.3% to 99.1% with the RSDs less than 7.2%.

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.

Toxicity of anthelmintic drugs (fenbendazole and flubendazole) to aquatic organisms

Flubendazole (FLU) and fenbendazole (FEN) belong to benzimidazoles-pharmaceuticals widely used in veterinary and human medicine for the treatment of intestinal parasites as well as for the treatment of systemic worm infections. In recent years, usage of these drugs increased, which resulted in a larger contamination of the environment and possible negative effects on biota. Hence, in our research, we investigated an aquatic ecotoxicity of these pharmaceuticals towards: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna). Ecotoxicity tests were combined with chemical analysis in order to investigate the actual exposure concentration of the compounds used in the experiment as well as to stability and adsorption studies. As a result, study evaluating sensitivity of different aquatic organisms to these compounds and new ecotoxicological data is presented. The strongest negative impact of FLU and FEN was observed to D. magna.

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.

Critical points in the evaluation of analytical methods based on liquid chromatography separation for the determination of doramectin in different environmental samples

In recent years, the number of analytical methods of target compound residues (such as pharmaceuticals) has grown rapidly. Most of them are based on high performance liquid chromatography (HPLC). From the economic point of view, it is usual to apply the conditions of available HPLC methods or to design extraction and chromatographic separation conditions using HPLC and transfer them subsequently to a more sensitive technique like liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). However, if such a transfer is planned, it is important to assess the quality of the newly-designed LC-MS/MS method. The determination of parameters like matrix effects (ME), extraction efficiency (EE) and absolute recovery (AR) is mandatory. These parameters can visualise the weakest step in the analytical method and enable methods based on different techniques to be compared. The aim of this work was to show how quality assessment should be carried out in order to transfer an optimised method from one technique to another. The representative compound used in our investigation was doramectin (DOR), an anthelmintic drug used in veterinary medicine. The quality of the suggested methods for determining this drug in three environmental matrices (water, sediment and fish tissue) using HPLC-UV and LC-MS/MS was evaluated on the basis of known values of absolute recovery (HPLC-UV) and matrix effect, extraction efficiency and absolute recovery (all LC-MS/MS). Finally, the suggested methods for determining DOR in water, sediment and fish tissue based on LC-MS/MS measurements were validated and applied to the analysis of real environmental samples.

A comprehensive approach to the determination of two benzimidazoles in environmental samples

Among the various pharmaceuticals regarded as emerging pollutants, benzimidazoles--represented by flubendazole and fenbendazole--are of particular concern because of their large-scale use in veterinary medicine and their health effects on aquatic organisms. For this reason, it is essential to have reliable analytical methods which can be used to simultaneously monitor their appearance in environmental matrices such as water, sediment and tissue samples. To date, however, such methods relating to these three matrices have not been available. In this paper we present a comprehensive approach to the determination of both drugs in the mentioned above matrices using liquid chromatography-ion trap mass spectrometry (LC-MS/MS). Special attention was paid to the sample preparation step. The optimal extraction methods were further validated by experiments with spiked water, sediment and fish tissue samples. Matrix effects were established. The following absolute recoveries of flubendazole and fenbendazole were achieved: 96.2% and 95.4% from waters, 103.4% and 98.3% from sediments, and 98.3% and 97.6% from fish tissue samples, respectively. Validation of the LC-MS/MS methods enable flubendazole and fenbendazole to be determined with method detection limits: 1.6 ng L(-1) and 1.7 ng L(-1) in water samples; 0.3 ng g(-1) for both compounds in sediment samples, and 3.3 ng g(-1) and 3.5 ng g(-1) in tissue samples, respectively. The proposed methods were successfully used for analysing selected pharmaceuticals in real samples collected in northern Poland. There is first data on the concentration in the environment of the target compounds in Poland.

Occurrence of pharmaceuticals in urban wastewater of north Indian cities and risk assessment

Six pharmaceuticals of different categories, such as nonsteroidal anti-inflammatory drugs (ibuprofen, ketoprofen, naproxen, diclofenac), anti-epileptic (carbamazepine), and anti-microbial (trimethoprim), were investigated in wastewater of the urban areas of Ghaziabad and Lucknow, India. Samples were concentrated by solid phase extraction (SPE) and determined by high-performance liquid chromatography (HPLC) methods. The SPE-HPLC method was validated according to the International Conference on Harmonization guidelines. All the six drugs were detected in wastewater of Ghaziabad, whereas naproxen was not detected in Lucknow wastewater. Results suggest that levels of these detected drugs were relatively higher in Ghaziabad as compared to those in Lucknow, and diclofenac was the most frequently detected drug in both the study areas. Detection of these drugs in wastewater reflects the importance of wastewater inputs as a source of pharmaceuticals. In terms of the regional distribution of compounds in wastewater of two cities, higher spatial variations (coefficient of variation 112.90-459.44%) were found in the Lucknow wastewater due to poor water exchange ability. In contrast, lower spatial variation (162.38-303.77%) was observed in Ghaziabad. Statistical analysis results suggest that both data were highly skewed, and populations in two study areas were significantly different (p < 0.05). A risk assessment based on the calculated risk quotient (RQ) in six different bioassays (bacteria, duckweed, algae, daphnia, rotifers, and fish) showed that the nonsteroidal anti-inflammatory drugs (NSAIDs) posed high (RQ >1) risk to all the test species. The present study would contribute to the formulation of guidelines for regulation of such emerging pharmaceutical contaminants in the environment.

Development of sensitive and reliable LC-MS/MS methods for the determination of three fluoroquinolones in water and fish tissue samples and preliminary environmental risk assessment of their presence in two rivers in northern Poland

Antibiotic consumption (e.g. fluoroquinolones (FQs)) and, as a consequence, their presence in the environment, have received a lot of attention in the last several years due to increasing numbers of diseases and infections that are becoming resistant to traditional treatments for both humans and animals. In addition, even though antibiotics are safe for human and veterinary usage, ecosystems may be exposed to these substances. In this study, analytical methods for determining enrofloxacin (ENR), norfloxacin (NOR) and ciprofloxacin (CIP) in water samples and fish tissue based on the LC-MS/MS technique were developed and validated. As there is no data available concerning the risks posed by antibiotics in Poland, the proposed methods were applied for monitoring drug presence in environmental samples collected from two rivers in northern Poland. Evaluations of the ecotoxicity of ENR, NOR and CIP towards four different species of aquatic organisms: marine bacteria (Vibrio fischeri), green algae (Scenedesmus vacuolatus), duckweed (Lemna minor) and crustacean (Daphnia magna), were also carried out. All the investigated compounds were detected at least once in the survey. NOR was found to be the most ubiquitous drug with concentrations of up to 442.8 ng L(-1). Moreover, it was established that L. minor is the most sensitive species to the investigated drugs (EC50NOR = 0.13 mg L(-1), EC50ENR = 0.22 mg L(-1) and EC50CIP = 0.34 mg L(-1)). The calculated risk quotient (RQ) values confirmed that the concentrations of the investigated FQs in the environmental samples were at a level of moderate environmental risk (1<RO ≤ 10), however, for CIP they were found to be closer to a level of high environmental risk (RQCIP = 8.1).

Effects of single and mixed estrogens on single and combined cultures of D. subspicatus and P. subcapitata

This paper investigates the effect of estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) individually and mixed at equal proportions (1:1:1) on Desmodesmus subspicatus and Pseudokirchneriella subcapitata in single and combined cultures (S+) at different exposure times based on algal growth (in vivo chlorophyll fluorescence and cell counting) and coenobium formation. EE2 and E2 were more toxic to individual and combined (S+) cultures than was E1. The frequency of coenobium formation by D. subspicatus increased significantly for all estrogens and all concentrations. After 96 h, D. subspicatus prevailed in S+. The results of the exposure to E+ suggested a less-than-additive effect on D. subspicatus and S+ and additive effect on P. subcapitata. Toxic effects occurred for both species exposed to E+ with individual estrogen concentrations below the NOEC of each species. Assays must include changes in response due to the exposure of more than one species to more than one estrogen.

Behaviour of nonsteroidal anti-inflammatory drugs and eight of their metabolites during wastewater treatment studied by hollow fibre liquid phase microextraction and liquid chromatography mass spectrometry

In this work hollow fibre liquid phase microextraction combined with liquid chromatography mass spectrometry was applied for the determination of the nonsteroidal anti-inflammatory drugs (NSAIDs) ketoprofen, naproxen, diclofenac and ibuprofen as well as eight of their known human metabolites in wastewater samples. Extraction time and addition of tri-n-octylphosphine oxide (TOPO) to the liquid membrane were evaluated resulting in a method with an optimal extraction time of 5h and 5% (w/V) TOPO addition to the membrane liquid (di-n-hexyl ether). With the optimized method, enrichment factors ranged between 778 and 4830. The method was applied for analysis of samples collected from Källby wastewater treatment plant in the city of Lund, Sweden. Samples were collected from the influent, water entering as well as exiting the conventional activated sludge treatment and the effluent to study the behaviour of these compounds during the treatment process. All twelve substances were found in the influent and for all four drugs, higher concentrations were detected of the metabolites than the parent compounds. Highest concentrations were detected of o-desmethylnaproxen, 2-hydroxyibuprofen and carboxyibuprofen (average influent concentrations of 45, 35 and 63 μg/L respectively). The study showed only partial removal during the primary treatment whereas both parent compounds and metabolites were efficiently removed during the activated sludge process. In the effluent all analytes were detected in concentrations below 1 μg/L thus showing that either the investigated metabolites do not belong to the NSAID transformation products formed during the activated sludge treatment or they are also quickly further transformed within the treatment.

Matrix effect during the membrane-assisted solvent extraction coupled to liquid chromatography tandem mass spectrometry for the determination of a variety of endocrine disrupting compounds in wastewater

Membrane-assisted solvent extraction (MASE) coupled to liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) was studied for the determination of a variety of emerging and priority compounds in wastewater. Among the target analytes studied certain hormones (estrone (E1), 17β-estradiol (E2), androsterone (ADT), 17α-ethynyl estradiol (EE2), diethylstilbestrol (DES), equilin (EQ), testosterone (TT), mestranol (MeEE2), 19-norethisterone (NT), progesterone (PG) and equilenin (EQN)), alkylphenols (APs) (4-tert-octylphenol (4tOP), nonylphenol technical mixture (NPs) and 4n-octylphenol (4nOP)) and BPA were included. The work was primarily focused in the LC-MS/MS detection step, both in terms of variable optimization and with respect to the matrix effect study. Both, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) were assessed both in the negative and positive mode, including the optimization of MS/MS operating conditions. The best results were obtained, in most of the cases, for ESI using 0.05% ammonium hydroxide as buffer solution in the mobile phase, composed with methanol and water. Under optimum detection conditions, matrix effect during the detection step was thoroughly studied. Dilution, correction with deuterated analogues and clean-up of the extracts were evaluated for matrix effect correction. Clean-up with Florisil together with correction with deuterated analogues provided the most satisfactory results, with apparent recoveries in the 57-136% range and method detection limits in the low ngL(-1) level for most of the analytes. For further validation of the method, two separated extraction procedures, the above mentioned MASE, and conventional solid phase extraction (SPE) were compared during the analysis of real samples and comparable results were successfully obtained for E1, E2, EE2, DES, NT, TT, EQ, PG, BPA, ADT, 4nOP, 4tOP, NPs and EQN.

A new analytical method to determine non-steroidal anti-inflammatory drugs in surface water using in situ derivatization combined with ultrasound-assisted emulsification microextraction followed by gas chromatography-mass spectrometry

Because of the high stability and potential toxic effects of non-steroidal anti-inflammatory drugs (NSAIDs), it is important to closely monitor their concentrations in the environment using a sensitive analytical method. In this study, a simple, rapid, efficient, and sensitive analytical method based on gas chromatography-mass spectrometry (GC-MS) was developed to determine the levels of seven common NSAIDs in various types of surface water. To simplify sample preparation, in situ derivatization using methyl chloroformate was combined with ultrasound-assisted emulsification microextraction. For selection and optimization of significant variables, experiments were statistically designed using Plackett-Burman design and central composite design. The resulting optimal conditions for derivatization and extraction were 100 μL of chloroform (extraction solvent), 10.0 mL of sample, and 240 μL of pyridine (catalyst as a base in derivatization). The optimized sample preparation coupled with optimized GC-MS analysis in selected ion monitoring mode provided good linearity from 0.010 to 5.0 ng mL(-1), and a limit of detection between 0.0050 and 0.010 ng mL(-1), good intra-day and inter-day precision (0.30-6.3% and 5.1-9.5%, respectively), and good accuracy (relative recovery; 91-117% at 0.20 ng mL(-1) and 77-105% at 2.5 ng mL(-1)). Compared with previously reported methods, the current method requires a small volume of sample and simple sample preparation steps for sensitive determination of NSAID levels using a conventional GC-MS system. The method was successfully applied to determine the levels of seven common NSAIDs in various types of surface water.

Novel magnetic multi-template molecularly imprinted polymers for specific separation and determination of three endocrine disrupting compounds simultaneously in environmental water samples

A novel type of superparamagnetic molecularly imprinted polymers introducing unique concept of multi-template for specific separation and determination of three endocrine disrupting compounds (EDCs) simultaneously.

Study of the uptake of non-steroid anti-inflammatory drugs in wheat and soybean after application of sewage sludge as a fertilizer

Non-steroid anti-inflammatory drugs (NSAIDs) are frequently occurring in sludge and waters from sewage treatment plants (STPs). Sludge obtained from sewage treatment is often applied as a fertilizer in agriculture and not many studies about the uptake of pharmaceuticals into crops can be found. In this paper, we present a greenhouse experiment to study the presence of four NSAIDs (naproxen, ketoprofen, diclofenac and ibuprofen) in two different crops (soybean and wheat) after application of sludge as a fertilizer. Two different amounts of sludge were added to the soil; the recommended amount (with respect to phosphorus content) and the double recommended amount. One treatment without sludge was also included as a blank. The crops were harvested after 60 as well as 110 days. Only diclofenac and ibuprofen were detected in the sludge in concentrations of 22 and 217 ng g(-1) dry weight, respectively. None of the NSAIDs were detected in the crops from any of the treatments. Compared to the amounts applied to the soil, detection limits correspond to an uptake of less than 2% for diclofenac and 0.8% for ibuprofen.