Determination of natural and synthetic estrogens in water by gas chromatography with mass spectrometric detection

Determination of diethylstilbestrol in environmental water based on electrochemical senser modified with vanadium based metal organic framework material composite

In this research, the MIL-47/ACET/Nafion/GCE electrochemical senser for the determination of diethylstilbestrol (DES) was prepared with vanadyl sulfate (VOSO4·nH2O) and terephthalic acid (H2BDC) as the main raw materials, compounded with acetylene black (ACET) and perfluorosulfonic acid polymer (Nafion). The compound DES belongs to the category of estrogens, and prolonged exposure to the environment can have detrimental effects on the physiological functioning of both humans and animals. Due to the strong DES enrichment performance of MIL-47(V-MOFs) with large specific surface area, in addition to the excellent conductivity and electrocatalysis of composite materials, this modified senser had good electrochemical response to DES. With differential pulse voltammetry, in optimum condition of 0.1 M NaH2PO4-Na2HPO4at pH = 7.0, potential interval of -1.0 to 1.0 V, enrichment time of 120 s and enrichment potential of 0.2 V, there was a good linear relationship between peak current and the concentration of DES over the range of 0.1 and 50μM, and the limit of detection was 0.008μM. The sensor accurately detected DES in actual water samples, with recovery rates ranging from 89.21% to 105.3%. The electrochemical sensor was simple to prepare and had practical significance for the detection of DES in water. The research results of the sensor provide another alternative analytical means for the sensitive detection of DES in the environment, which is important for maintaining public health.

Tox21-Based Comparative Analyses for the Identification of Potential Toxic Effects of Environmental Pollutants

Chemical pollution has become a prominent environmental problem. In recent years, quantitative high-throughput screening (qHTS) assays have been developed for the fast assessment of chemicals' toxic effects. Toxicology in the 21st Century (Tox21) is a well-known and continuously developing qHTS project. Recent reports utilizing Tox21 data have mainly focused on setting up mathematical models for in vivo toxicity predictions, with less attention to intuitive qHTS data visualization. In this study, we attempted to reveal and summarize the toxic effects of environmental pollutants by analyzing and visualizing Tox21 qHTS data. Via PubMed text mining, toxicity/structure clustering, and manual classification, we detected a total of 158 chemicals of environmental concern (COECs) from the Tox21 library that we classified into 13 COEC groups based on structure and activity similarities. By visualizing these COEC groups' bioactivities, we demonstrated that COECs frequently displayed androgen and progesterone antagonistic effects, xenobiotic receptor agonistic roles, and mitochondrial toxicity. We also revealed many other potential targets of the 13 COEC groups, which were not well illustrated yet, and that current Tox21 assays may not correctly classify known teratogens. In conclusion, we provide a feasible method to intuitively understand qHTS data.

Development and application of an in-house library and workflow for gas chromatography-electron ionization-accurate-mass/high-resolution mass spectrometry screening of environmental samples

This work presents an optimized gas chromatography–electron ionization–high-resolution mass spectrometry (GC-EI-HRMS) screening method. Different method parameters affecting data processing with the Agilent Unknowns Analysis SureMass deconvolution software were optimized in order to achieve the best compromise between false positives and false negatives. To this end, an accurate-mass library of 26 model compounds was created. Then, five replicates of mussel extracts were spiked with a mixture of these 26 compounds at two concentration levels (10 and 100 ng/g dry weight in mussel, 50 and 500 ng/mL in extract) and injected in the GC-EI-HRMS system. The results of these experiments showed that accurate mass tolerance and pure weight factor (combination of reverse-forward library search) are the most critical factors. The validation of the developed method afforded screening detection limits in the 2.5–5 ng range for passive sampler extracts and 1–2 ng/g for mussel sample extracts, and limits of quantification in the 0.6–3.2 ng and 0.1–1.8 ng/g range, for the same type of samples, respectively, for 17 model analytes. Once the method was optimized, an accurate-mass HRMS library, containing retention indexes, with ca. 355 spectra of derivatized and non-derivatized compounds was generated. This library (freely available at https://doi.org/10.5281/zenodo.5647960), together with a modified Agilent Pesticides Library of over 800 compounds, was applied to the screening of passive samplers, both of polydimethylsiloxane and polar chemical integrative samplers (POCIS), and mussel samples collected in Galicia (NW Spain), where a total of 75 chemicals could be identified.

Quantitative Determination and Environmental Risk Assessment of 102 Chemicals of Emerging Concern in Wastewater-Impacted Rivers Using Rapid Direct-Injection Liquid Chromatography-Tandem Mass Spectrometry

The rapid source identification and environmental risk assessment (ERA) of hundreds of chemicals of emerging concern (CECs) in river water represent a significant analytical challenge. Herein, a potential solution involving a rapid direct-injection liquid chromatography-tandem mass spectrometry method for the quantitative determination of 102 CECs (151 qualitatively) in river water is presented and applied across six rivers in Germany and Switzerland at high spatial resolution. The method required an injection volume of only 10 µL of filtered sample, with a runtime of 5.5 min including re-equilibration with >10 datapoints per peak per transition (mostly 2 per compound), and 36 stable isotope-labelled standards. Performance was excellent from the low ng/L to µg/L concentration level, with 260 injections possible in any 24 h period. The method was applied in three separate campaigns focusing on the ERA of rivers impacted by wastewater effluent discharges (1 urban area in the Basel city region with 4 rivers, as well as 1 semi-rural and 1 rural area, each focusing on 1 river). Between 25 and 40 compounds were quantified directly in each campaign, and in all cases small tributary rivers showed higher CEC concentrations (e.g., up to ~4000 ng/L in total in the R. Schwarzach, Bavaria, Germany). The source of selected CECs could also be identified and differentiated from other sources at pre- and post- wastewater treatment plant effluent discharge points, as well as the effect of dilution downstream, which occurred over very short distances in all cases. Lastly, ERA for 41 CECs was performed at specific impacted sites, with risk quotients (RQs) at 1 or more sites estimated as high risk (RQ > 10) for 1 pharmaceutical (diclofenac), medium risk (RQ of 1-10) for 3 CECs (carbamazepine, venlafaxine, and sulfamethoxazole), and low risk (RQ = 0.1-1.0) for 7 CECs (i.e., RQ > 0.1 for 11 CECs in total). The application of high-throughput methods like this could enable a better understanding of the risks of CECs, especially in low flow/volume tributary rivers at scale and with high resolution.

Preparation of magnetic molecularly imprinted polymers for the rapid detection of diethylstilbestrol in milk samples

BACKGROUND

Diethylstilbestrol (DES) residues are harmful to human health because of their potential carcinogenic properties. Therefore, it is important to develop a fast and efficient pretreatment method to prevent their harmful effects on human health and the environment.

RESULTS

In this paper, two types of magnetic molecularly imprinted polymers (MMIPs) of DES were prepared by bulk polymerization and the sol-gel method, respectively. The synthetic materials were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. Adsorption capacities of the bulk and sol-gel MMIPs were investigated. A rapid detection method was developed using the two types of MMIPs as sorbents, coupled to high-performance liquid chromatography, for the determination of DES residues in milk samples. Under optimized conditions, the limit of detection (S/N = 3) of both methods for DES was 2.0 μg L^-1 ; and the linear response range to DES was 0.1-500 mg L^-1 . The milk samples were analyzed according to this method with good recoveries of 88.3-97.6 and 90.5-103.5% for the two types of MMIPs, respectively.

CONCLUSIONS

The method described had high sensitivity and high selectivity, and could prove to be a new method for the rapid determination of DES residues in milk samples. © 2019 Society of Chemical Industry.

Reproductive drugs and environmental contamination: quantum, impact assessment and control strategies

Industrial and municipal solid wastes, noise, pesticides, fertilizers and vehicular emission are visible pollutants responsible for environmental contamination and ill-effects on health of all living systems. But, environmental contamination due to drugs or medicines used for different purposes in humans and animals goes unseen largely and can affect the health of living system severely. During the last few decades, the usage of drugs has increased drastically, resulting in increased drug load in soil and water. Contraceptive and fertility drugs are extensively and effectively used in humans as well as animals for different purposes. Usage of these reproductive drugs in humans is increased manifold to manage reproductive problems and/or for birth control with changing lifestyles. These drugs are excreted in urine and faeces as metabolite or conjugated forms, leading to contamination of water, milk and animal produce, which are consumed directly by humans as well as animals. These drugs are not eliminated even by water treatment plant. Consumption of such contaminated water, milk, meat and poultry products results in reproductive disorders such as fertility loss in men and increase risk of different types of cancers in humans. Therefore, assessment of impact of environmental contamination by these drugs on living system is of paramount importance. The purpose of this review article is to provide a comprehensive analysis of various research and review reports on different contraceptive and fertility drugs used in human and animals, their occurrence in the environment and their ill-effects on living systems. The approaches to control this invisible menace have also been proposed.

One-step synthesis of S,B co-doped carbon dots and their application for selective and sensitive fluorescence detection of diethylstilbestrol

S,B co-doped carbon dots were synthesized, and their application in the detection of diethylstilbestrol.

Novel generation of deep eutectic solvent as an acceptor phase in three-phase hollow fiber liquid phase microextraction for extraction and preconcentration of steroidal hormones from biological fluids

In this study, a novel generation of deep eutectic solvents (DESs) was used as an acceptor phase in three-phase hollow fiber liquid phase microextraction (HF-LPME) based on two immiscible organic phases. It was compared with other common DESs for extraction and preconcentration of dydrogesterone (DYD) and cyproterone acetate (CPA) from urine and plasma samples. The extracted analytes were analyzed by high performance liquid chromatography with UV-vis detector (HPLC-UV). This phosphonium based DES due to low volatility, low price and multifunctionality introduced itself as worthy next generation of acceptor phase in HF-LPME. The factors affected on extraction efficiency of the analytes were investigated and optimized. The performance of the proposed method was studied in terms of linear ranges (LRs from 1 to 500µgL^-1 with R² ≥ 0.9946), precision (RSD% ≤ 6.3) and limits of detection (LODs in the range of 0.5-2µgL^-1). Under the optimized conditions, preconcentration factors in the range of 187-428 were obtained. Finally, the method was applied to the analysis of DYD and CPA in human urine and plasma samples and desirable results were obtained.

Procedures of determining organic trace compounds in municipal sewage sludge-a review

Sewage sludge is the largest by-product generated during the wastewater treatment process. Since large amounts of sludge are being produced, different ways of disposal have been introduced. One tempting option is to use it as fertilizer in agricultural fields due to its high contents of inorganic nutrients. This, however, can be limited by the amount of trace contaminants in the sewage sludge, containing a variety of microbiological pollutants and pathogens but also inorganic and organic contaminants. The bioavailability and the effects of trace contaminants on the microorganisms of soil are still largely unknown as well as their mixture effects. Therefore, there is a need to analyze the sludge to test its suitability before further use. In this article, a variety of sampling, pretreatment, extraction, and analysis methods have been reviewed. Additionally, different organic trace compounds often found in the sewage sludge and their methods of analysis have been compiled. In addition to traditional Soxhlet extraction, the most common extraction methods of organic contaminants in sludge include ultrasonic extraction (USE), supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), and pressurized liquid extraction (PLE) followed by instrumental analysis based on gas or liquid chromatography and mass spectrometry.

Fluorescent aptasensor for 17β-estradiol determination based on gold nanoparticles quenching the fluorescence of Rhodamine B

In this paper, we developed a fluorescent aptasensor for 17β-estradiol (E2) determination in aqueous solution using label-free E2-specific aptamer, gold nanoparticles (AuNPs) and Rhodamine B (RhoB) as sensing probe, fluorescent quencher and fluorescent indicator respectively. In the absence of E2, AuNPs were wrapped by E2 aptamer and maintained dispersed in NaCl solution basically. These dispersed AuNPs could effectively impair the originally high fluorescence of RhoB. Contrarily, in the presence of E2, E2 aptamer could specifically combine with E2 to form E2-aptamer complex, so the AuNPs were released by E2 aptamer and aggregated under the influence of NaCl. The aggregated AuNPs have a weak influence on RhoB fluorescence. Therefore, the E2 concentration can be determined by the change of fluorescence intensity of RhoB. This fluorescent assay has a detection limit as low as 0.48 nM, a linear range from 0.48 to 200 nM, and high selectivity over other disrupting chemicals. It was applied to determine E2 in water samples with recoveries in the range of 94.3-111.7%. The fluorescent aptasensor holds great potential for E2 detection in environmental water samples.

Status of hormones and painkillers in wastewater effluents across several European states-considerations for the EU watch list concerning estradiols and diclofenac

Present technologies for wastewater treatment do not sufficiently address the increasing pollution situation of receiving water bodies, especially with the growing use of personal care products and pharmaceuticals (PPCP) in the private household and health sector. The relevance of addressing this problem of organic pollutants was taken into account by the Directive 2013/39/EU that introduced (i) the quality evaluation of aquatic compartments, (ii) the polluter pays principle, (iii) the need for innovative and affordable wastewater treatment technologies, and (iv) the identification of pollution causes including a list of principal compounds to be monitored. In addition, a watch list of 10 other substances was recently defined by Decision 2015/495 on March 20, 2015. This list contains, among several recalcitrant chemicals, the painkiller diclofenac and the hormones 17β-estradiol and 17α-ethinylestradiol. Although some modern approaches for their removal exist, such as advanced oxidation processes (AOPs), retrofitting most wastewater treatment plants with AOPs will not be acceptable as consistent investment at reasonable operational cost. Additionally, by-product and transformation product formation has to be considered. The same is true for membrane-based technologies (nanofiltration, reversed osmosis) despite of the incredible progress that has been made during recent years, because these systems lead to higher operation costs (mainly due to higher energy consumption) so that the majority of communities will not easily accept them. Advanced technologies in wastewater treatment like membrane bioreactors (MBR) that integrate biological degradation of organic matter with membrane filtration have proven a more complete elimination of emerging pollutants in a rather cost- and labor-intensive technology. Still, most of the presently applied methods are incapable of removing critical compounds completely. In this opinion paper, the state of the art of European WWTPs is reflected, and capacities of single methods are described. Furthermore, the need for analytical standards, risk assessment, and economic planning is stressed. The survey results in the conclusion that combinations of different conventional and advanced technologies including biological and plant-based strategies seem to be most promising to solve the burning problem of polluting our environment with hazardous emerging xenobiotics.

Synthesis of mimic molecularly imprinted ordered mesoporous silica adsorbent by thermally reversible semicovalent approach for pipette-tip solid-phase extraction-liquid chromatography fluorescence determination of estradiol in milk

A mimic molecularly imprinted ordered mesoporous silica (MIOMS) adsorbent was prepared utilizing a thermally reversible semicovalent approach. The thermally reversible covalent template-monomer complex was firstly synthesized by employing 4,4'-sulfonyldiphenol (BPS) and (3-isocyanatopropyl) triethoxysilane (ICPTES) as template and monomer, respectively. The template-monomer complex was incorporated into ordered mesoporous silica via a simple self-assembly process. The adsorption experiment illustrated that the imprint-removed silica (MIOMS-ir) had higher special recognition ability (250μgg(-1)) for estradiol (E2) than the non-imprinted silica (NIOMS-ir) (25μgg(-1)). MIOMS-ir was applied as an adsorbent in pipette-tip solid-phase extraction (PT-SPE) coupled with liquid chromatography-fluorescence detector (LC-FLD) for determination of E2 in milk samples. Under the optimized conditions, only 3mg of the adsorbent, 0.3mL of water as washing solvent, and 0.5mL of acetonitrile-acetic acid (96:4, v/v) as elution solvent were used in the pretreatment procedure of milk samples. Good calibration linearity was obtained in a range of 25ngL(-1) to 1000ngL(-1), and the recoveries at three spiked levels were ranged from 95.4% to 107.0% with relative standard deviations (RSDs) ≤3.1% (n=3). The proposed MIOMS-ir-PT-SPE-LC-FLD method combined the advantages of PT-SPE and ordered mesoporous material such as ease assembly, low cost, high extraction efficiency and large specific surface area, so it is a potential pretreatment strategy for the extraction and determination of E2 in complex milk samples.

Bioaugmentation Mitigates the Impact of Estrogen on Coliform-Grazing Protozoa in Slow Sand Filters

Exposure to endocrine-disrupting chemicals (EDCs), such as estrogens, is a growing issue for human and animal health as they have been shown to cause reproductive and developmental abnormalities in wildlife and plants and have been linked to male infertility disorders in humans. Intensive farming and weather events, such as storms, flash flooding, and landslides, contribute estrogen to waterways used to supply drinking water. This paper explores the impact of estrogen exposure on the performance of slow sand filters (SSFs) used for water treatment. The feasibility and efficacy of SSF bioaugmentation with estrogen-degrading bacteria was also investigated, to determine whether removal of natural estrogens (estrone, estradiol, and estriol) and overall SSF performance for drinking water treatment could be improved. Strains for SSF augmentation were isolated from full-scale, municipal SSFs so as to optimize survival in the laboratory-scale SSFs used. Concentrations of the natural estrogens, determined by gas chromatography coupled with mass spectrometry (GC-MS), revealed augmented SSFs reduced the overall estrogenic potency of the supplied water by 25% on average and removed significantly more estrone and estradiol than nonaugmented filters. A negative correlation was found between coliform removal and estrogen concentration in nonaugmented filters. This was due to the toxic inhibition of protozoa, indicating that high estrogen concentrations can have functional implications for SSFs (such as impairing coliform removal). Consequently, we suggest that high estrogen concentrations could impact significantly on water quality production and, in particular, on pathogen removal in biological water filters.

Analytical methods for the endocrine disruptor compounds determination in environmental water samples

The potential risk of exposure to different xenobiotics, which can modulate the endocrine system and represent a treat for the wellness of an increasing number of people, has recently drawn the attention of international environmental and health agencies. Several agents, characterized by structural diversity, may interfer with the normal endocrine functions that regulate cell growth, homeostasis and development. Substances such as pesticides, herbicides, plasticizers, metals, etc. having endocrine activity (EDCs) are used in agriculture and industry and are also used as drugs for humans and animals. A difficulty in the analytical determination of these substances is the complexity of the matrix in which they are present. In fact, the samples most frequently analyzed consist of groundwater and surface water, including influent and effluent of wastewater treatment plants and drinking water. In this review, several sample pretreatment protocols, assays and different instrumental techniques recently used in the EDCs determination have been considered. This review concludes with a paragraph in which the most recent hyphenated-instrument techniques are treated, highlighting their sensitivity and selectivity for the analyses of environmental water samples.

A time-resolved fluorescence immunoassay for the ultrasensitive determination of diethylstilbestrol based on the double-codified gold nanoparticles

An ultrasensitive and selective method is presented for the determination of diethylstilbestrol (DES) using time-resolved fluorescence immunoassay (TRFIA) based on double-codified gold nanoparticles (DC-AuNPs). In this system, the DC-AuNPs, that are gold nanoparticles (AuNPs) modified with anti-DES antibody and SH-dsDNA-biotin, was regarded as signal amplifier. A competitive immunoreaction was performed on polystyrene microtitration plates, where the DES compete with the immobilized DES-ovalbumin on polystyrene microtitration plates to bind to anti-DES antibodies on DC-AuNPs, and the europium(III)-labeled streptavidin was added to link to the SH-dsDNA-biotin as a tracer. Fluorescence signal was amplified via the AuNPs and the biotin-streptavidin double amplification systems. Under the optimized condition, DES can be quantified by TRFIA. The linear range and the limit of detection of DES were 1.0×10(-6)-10ngmL(-1) and 0.4fgmL(-1), respectively. This method was applied to determine DES in beef sample, with the recoveries ranging from 88% to 105%.

Occurrence and removal of estrogens in Brazilian wastewater treatment plants

This paper evaluated the occurrence and removal efficiency of four estrogenic hormones in five biological wastewater treatment plants (WWTPs), located in the State of Ceará, Brazil. The five WWTPs comprised: two systems consisted of one facultative pond followed by two maturation ponds, one facultative pond, one activated sludge (AS) system followed by a chlorination step, and one upflow anaerobic sludge blanket (UASB) reactor followed by a chlorination step. Estrogen occurrence showed a wide variation among the analyzed influent and effluent samples. Estrone (E1) showed the highest occurrence in the influent (76%), whereas both 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) presented a 52% occurrence, and the compound 17β-estradiol 17-acetate (E2-17A), a 32% one. The occurrence in the effluent samples was 48% for E1, 28% for E2, 12% for E2-17A, and 40% for EE2. The highest concentrations of E1 and EE2 hormones in the influent were 3050 and 3180 ng L(-1), respectively, whereas E2 and E2-17A had maximum concentrations of 776 and 2300 ng L(-1), respectively. The lowest efficiencies for the removal of estrogenic hormones were found in WWTP consisted of waste stabilization ponds, ranging from 54 to 79.9%. The high-rate systems (AS and UASB), which have chlorination as post-treatment, presented removal efficiencies of approximately 95%.

Comparison of different mesoporous silicas for off-line solid phase extraction of 17β-estradiol from waters and its determination by HPLC-DAD

Functionalized (SBA-C₁₈ and SM-C₁₈) and non-functionalized (SBA-15 and SM) mesoporous silicas were then examined as sorbents for solid-phase extraction of 17β-estradiol in aqueous media. Experiments were run in order to test critical factors affecting the procedure extraction efficiency, including the type of sorbent, the analyte concentration, the solvent and volume used for elution and the sample volume. Among the prepared materials, SBA-C₁₈ had the highest adsorption affinity towards 17β-estradiol and under optimized conditions (200mg of sorbent, 150 mL of water sample, elution with 3 × 2 mL of methanol) this sorbent proved good extraction capacity and elution efficiency for this hormone from aqueous media (recovery near 100%). To evaluate the analytical applicability of the proposed method, it was applied to the determination of 17β-estradiol in drinking water by high performance liquid chromatography with a photodiode array detector. Calibration curves were shown to be linear between 1.25 and 100 mg L(-1)with correlation coefficients ≥0.999 (n=5) for 17β-estradiol. The instrumental detection and quantitation limits calculated were 0.38 and 1.25 mg L(-1), respectively. The relative standard deviation obtained values were ≤3% and the mean recoveries obtained were of 82%. The results suggest that SBA-C18 is a promising material for the off-line solid phase extraction of 17β-estradiol from waters.

Analysis of bisphenol A, nonylphenol, and natural estrogens in vegetables and fruits using gas chromatography-tandem mass spectrometry

Bisphenol A (BPA), nonylphenol (NP), and steroidal estrogens in vegetables and fruits were analyzed using gas chromatography with tandem mass spectrometry (GC-MS/MS). Isotope dilution standards were spiked before the extraction to account for extraction inefficiency and loss of analytes during sample workup. Recoveries were >90% for all of the compounds in each matrix. The limit of detection (LOD) ranged from 0.03 to 0.3 μg kg(-1), whereas the limit of quantitation (LOQ) ranged from 0.1 to 1.0 μg kg(-1). All analytes can be monitored in a single GC-MS/MS run with a run time of 20 min. Occurrence of these endocrine-disrupting chemicals (EDCs) in vegetables and fruits from local markets was observed using the established analytical method. BPA was detected in all vegetable and fruit samples, ranging from 0.2 ± 0.1 to 9.0 ± 4.9 μg kg(-1), indicating significant exposure potential for humans. NP was detected in pumpkin, sweet potato, citrus, and apple samples. The concentration of 4-n-NP ranged from 5.3 ± 2.4 to 18.9 ± 8.0 μg kg(-1), whereas that of 4-NP ranged from 5.1 ± 2.6 to 12.2 ± 3.6 μg kg(-1). Concentrations of 17-β-estradiol in vegetables and fruits ranged from 1.3 ± 0.4 to 2.2 ± 1.0 μg kg(-1) except those in tomato and strawberry, in which no 17-β-estradiol was detected. The estimated daily intake of 17-β-estradiol was beyond the recommended acceptable daily intake (ADI) for children as recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Occurrence of bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol in Portuguese rivers

This study focused on the occurrence of several EDCs including bisphenol A, estrone (E1), the 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in fourteen rivers of Portugal. Samples analysis revealed a widespread contamination of BPA especially in Ave, Cávado, Douro, Ferro, Sousa and Vizela Rivers. Achieving 98.4 ng/L for the highest concentration. The estrogens achieved above the method quantification limit (MQL) were E1 in Águeda River and E2 in Ave, Lima and Tâmega Rivers. The maximum concentration detected for E1 was 26.9 ng/L. EE2 was detected only below MQL.

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.

Effect of process conditions on the analysis of free and conjugated estrogen hormones by solid-phase extraction-gas chromatography/mass spectrometry (SPE-GC/MS)

Simultaneous analysis of 11 free estrogen hormones and five conjugated estrogens in water and municipal wastewater was studied. The analytical method was developed and tested for different types of solid-phase extraction adsorbents, eluents, sample containers and storage conditions, derivatization, and matrix effects. Varian Bond Elut C-18 solid-phase extraction adsorbent cartridge was selected based on its high recoveries for both free and conjugated estrogens. Sample storage conditions, as well as selection and pretreatment of sample container materials, can affect the trace level analysis of estrogens. Silanization of glassware is observed to provide low relative standard deviation (RSD) in the analysis and less percentage loss due to contacting with sample container materials. Light exposure during the test can significantly impact the results. The derivatized samples stored at -20°C for at least 6 days showed less than 10.5% average RSD in the analysis. The recovery efficiency in clean water varies from 72% to 101% for free estrogens and 78% to 82% for conjugated estrogens. The method detection limits (MDL) for most of the compounds range from 30 to 870 ng/L using a sample volume of 200 mL. With a sample volume of 3 L, the most sensitive compound produces a MDL of 0.03 ng/L. Dilute methanol is used to wash the loaded cartridge as a cleanup step in order to remove interfering species during analysis of wastewater samples. Using the optimized analytical methods, the concentration level of free estrogens in the influent and effluent municipal wastewaters is tested.