Determination of steroidal oestrogens in tap water samples using solid-phase extraction on a molecularly imprinted polymer sorbent and quantification with gas chromatography-mass spectrometry (GC-MS)

Novel ferrofluid based on hydrophobic deep eutectic solvents for separation and analysis of trace estrogens in environmental water and urine samples

A novel ferrofluid prepared from a hydrophobic deep eutectic solvent (DES) and Fe3O4@graphite composite materials was introduced as a green microextraction medium for the separation and enrichment of trace estrogens in real samples. It was found that the ferrofluid greatly improved the capacity and selectivity of target analytes, benefiting from the enrichment of both DES and Fe3O4@graphite composite materials. Using a combination of high-performance liquid chromatography-fluorescence detection (HPLC-FLD) and vortex-assisted liquid-liquid microextraction (VALLME), a new method was established for simultaneous rapid processing and accurate determination of three estrogens (estradiol [E2], estriol [E3], and ethinyl estradiol [EE2]) in environmental water and urine samples. Key parameters affecting the extraction efficiency were optimized using a single-factor approach and response surface methodology. Under optimal conditions, this method yielded a low limit of detection (1.01 ng L-1, 3.03 ng L-1, and 25.0 ng L-1 for EE2, E2, and E3, respectively), wide linear range (3-200,000 ng L-1), high enrichment factors (9.81-47.2), and satisfactory recovery (73.8-129.0%). Compared with traditional analytical techniques, this method avoids the use of volatile toxic organic extraction solvents and cumbersome phase separation operations.

Biological effect and chemical monitoring of Watch List substances in European surface waters: Steroidal estrogens and diclofenac - Effect-based methods for monitoring frameworks

Three steroidal estrogens, 17α-ethinylestradiol (EE2), 17β-estradiol (E2), estrone (E1), and the non-steroidal anti-inflammatory drug (NSAID), diclofenac have been included in the first Watch List of the Water Framework Directive (WFD, EU Directive 2000/60/EC, EU Implementing Decision 2015/495). This triggered the need for more EU-wide surface water monitoring data on these micropollutants, before they can be considered for inclusion in the list of priority substances regularly monitored in aquatic ecosystems. The revision of the priority substance list of the WFD offers the opportunity to incorporate more holistic bioanalytical approaches, such as effect-based monitoring, alongside single substance chemical monitoring. Effect-based methods (EBMs) are able to measure total biological activities (e.g., estrogenic activity or cyxlooxygenase [COX]-inhibition) of specific group of substances (such as estrogens and NSAIDs) in the aquatic environment at low concentrations (pg/L). This makes them potential tools for a cost-effective and ecotoxicologically comprehensive water quality assessment. In parallel, the use of such methods could build a bridge from chemical status assessments towards ecological status assessments by adressing mixture effects for relevant modes of action. Our study aimed to assess the suitability of implementing EBMs in the WFD, by conducting a large-scale sampling and analysis campaign of more than 70 surface waters across Europe. This resulted in the generation of high-quality chemical and effect-based monitoring data for the selected Watch List substances. Overall, water samples contained low estrogenicity (0.01-1.3 ng E2-Equivalent/L) and a range of COX-inhibition activity similar to previously reported levels (12-1600 ng Diclofenac-Equivalent/L). Comparison between effect-based and conventional analytical chemical methods showed that the chemical analytical approach for steroidal estrogens resulted in more (76%) non-quantifiable data, i.e., concentrations were below detection limits, compared to the EBMs (28%). These results demonstrate the excellent and sensitive screening capability of EBMs.

Sample Preparation and Analytical Methods for Steroid Hormones in Environmental and Food Samples: An Update Since 2012

Steroid hormones (SHs) have been widely used over the past few decades as both human and veterinary drugs to prevent or treat infectious diseases and anti-inflammatory benefits in clinical. Unfortunately, their residues in foodstuffs and environmental samples can produce adverse effects on human and animal life such as disrupting the endocrine system. For these reasons, sensitive, simple and efficient methods have been developed for the determination of these compounds in various matrices. This critical review summarized the articles published in the period from 2012 to 2019 and can be used to help researchers to understand development of the sample pretreatment protocols and analytical methods used to detect SHs. The developed extraction and purification techniques used for steroids in different samples, such as cloud point extraction, solid phase extraction based on different novel materials, microextraction methods, QuEChERS and other methods are summarized and discussed. Analytical methods used to quantify these compounds, such as different chromatography methods, electrochemical methods, as well as other methods, are illustrated and compared. We focused on the latest advances in SHs pretreatment, and the application of new technologies in SHs analysis.

Voltammetric determination of ethinylestradiol using screen-printed electrode modified with functionalized graphene, graphene quantum dots and magnetic nanoparticles coated with molecularly imprinted polymers

The present work reports the development of a sensitive and selective method for ethinylestradiol detection using screen-printed electrode (SPE) modified with functionalized graphene (FG), graphene quantum dots (GQDs) and magnetic nanoparticles coated with molecularly imprinted polymers (mag@MIP). The performance of the mag@MIP sensor was compared with that of a non-molecularly imprinted sensor (mag@NIP). Chemical and physical characterizations of the mag@NIP and mag@MIP sensors were performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Brunauer-Emmett-Teller (BET) techniques. The electrochemical behavior of the electrodes investigated, which included (mag@MIP)-GQDs-FG-NF/SPE, (mag@NIP)-GQDs-FG-NF/SPE, GQDs-FG-NF/SPE and FG-NF/SPE, was evaluated by cyclic voltammetry. The results obtained show a significant increase in peak current magnitude for (mag@MIP)-GQDs-FG-NF/SPE. Using square wave voltammetry experiments, the efficiency of the (mag@MIP)-GQDs-FG-NF/SPE sensor was also tested under optimized conditions. The linear response range obtained for ethinylestradiol concentration was 10 nmol L^-1 to 2.5 μmol L^-1, with limit of detection of 2.6 nmol L^-1. The analytical signal of the (mag@MIP)-GQDs-FG-NF/SPE sensor suffered no interference from different compounds and the sensor exhibited good repeatability. The proposed sensor was successfully applied for ethynilestradiol detection in river water, serum and urine samples, where recovery rates between 96 to 105% and 97-104% were obtained for environmental and biological samples, respectively.

Occurrence and assessment of environmental risks of endocrine disrupting compounds in drinking, surface and wastewaters in Serbia

The present study is the first comprehensive monitoring of 13 selected endocrine disrupting compounds (EDCs) in untreated urban and industrial wastewater in Serbia to assess their impact on the Danube River basin and associated freshwaters used as sources for drinking water production in the area. Results showed that natural and synthetic estrogens were present in surface and wastewater at concentrations ranging from 0.1 to 64.8 ng L^-1. Nevertheless, they were not detected in drinking water. For alkylphenols concentrations ranged from 1.1 to 78.3 ng L^-1 in wastewater and from 0.1 to 37.2 ng L^-1 in surface water, while in drinking water concentrations varied from 0.4 to 7.9 ng L^-1. Bisphenol A (BPA) was the most abundant compound in all water types, with frequencies of detection ranging from 57% in drinking water, to 70% in surface and 84% in wastewater. Potential environmental risks were characterized by calculating the risk quotients (RQs) and the estrogenic activity of EDCs in waste, surface and drinking water samples, as an indicator of their potential detrimental effects. RQ values of estrone (E1) and estradiol (E2) were the highest, exceeding the threshold value of 1 in 60% of wastewater samples, while in surface water E1 displayed potential risks in only two samples. Total estrogenic activity (EEQ_t) surpassed the threshold of 1 ng E2 L^-1 in about 67% of wastewater samples, and in 3 surface water samples. In drinking water, EEQ_t was below 1 ng L^-1 in all samples.

Molecularly imprinted polymers for the detection of benomyl residues in water and soil samples

Benomyl is a benzimidazol fungicide used against various crop pathogens. Although banned in many countries, it is still widely used worldwide and is listed in different monitoring programs among the substances to be monitored to assess human exposure to pesticide residues. The assessment of benomyl is mainly based on the analysis of the residues of its most important metabolite, carbendazim. Existing methods often lack of selectivity and display a limited performance because of the presence of co-extracted compounds. Molecularly imprinted polymers (MIPs) offer an alternative methodology, adsorbing preferentially those target molecules for which the polymers are specifically prepared. In this study, we optimized the synthesis of a polymer imprinted with benomyl. Tests of specificity recognition showed a good performance for carbendazim compared with other similar pesticides. The mean recovery of benomyl (measured as carbendazim) from water samples was estimated to be 90% for MIPs while with real soil samples collected in Morocco the recovery efficiency was 62%. Preliminary tests also suggest that this MIP can implement traditional SPE techniques for assessing benomyl residual concentrations in environmental samples.

Recent applications of gas chromatography with high-resolution mass spectrometry

Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well.

A survey of 17α-ethinylestradiol and mestranol residues in Hawkesbury River, Australia, using a highly specific enzyme-linked immunosorbent assay (ELISA) demonstrates the levels of potential biological significance

This study reports on the potential status of 17α-ethinylestradiol (EE2) and mestranol (MeEE2) residues in aquatic environments in New South Wales (NSW), Australia, based on the analysis by a specific ELISA we developed. Polyclonal antibodies were raised against the EE2 hapten with a linker attached at the C3-position to direct the antibody binding towards the ring D of EE2/MeEE2. Using this approach, an ELISA highly specific to EE2 and MeEE2 was successfully developed, showing less than 3.1% cross-reactivity (% CR) with other major steroidal sex hormones and their derivatives. The assay performed with the limit of detection (LOD) of 0.04 ± 0.01µg/L for both EE2 and MeEE2, and the limit of quantitation (LOQ) of 0.05 ± 0.01ng/L when it was coupled with the SM2-Biobeads solid phase extraction. Prior to conducting the survey study, it was validated against the gas chromatography-mass spectrophotometry (GC-MS) method, which showed high correlation with R² of 0.934. Fresh surface water samples collected at different sites along Hawkesbury River in New South Wales (NSW) were analyzed for the EE2/ MeEE2 residues using the developed ELISA. The EE2/MeEE2 levels were found to range between 4.1 and 8.3ng/L in Emigrant Creek, NSW, where the primary activity was macadamia plantation, and higher levels between 15 and 29ng/L in South Creek, NSW, Greater Western Sydney at sites upstream and downstream of the municipal sewage treatment plants.