Molecularly imprinted polymer film grafted from porous silica for efficient enrichment of steroid hormones in water samples

Preparation of a sustainable magnetic sorbent for the extraction and preconcentration of progestogens in natural water samples

A film composed of agarose and graphene (G) and magnetic nanoparticles (G-MNPs) is proposed as a sorbent for the extraction and determination of medroxyprogesterone (MED), levonorgestrel (LEV), norethisterone (NOR) and progesterone (PRO) in natural water samples. Both the preparation of the film and the extraction procedure were optimized. The optimal extraction parameters were as follows: isopropyl alcohol as activation solvent, sample pH value of 3.0, extraction time of 30 min, 1.00 mL of acetonitrile as eluent, elution time of 5 min and sample volume of 100.00 mL. HPLC with photodiode array detector was used for the separation and determination. The method presented a linear range between 2.50 and 75.0 μg L-1 for all analytes, and the LODs were between 1.40 and 1.80 μg L-1. The method was applied to natural water samples, obtaining satisfactory recovery values (75-111 %). In conclusion, for the immobilization of the G-MNPs, agarose was used, which is a non-toxic, renewable and biodegradable material. The G-MNPs-agarose film was reused up to 70 times, without losing its extraction capacity significantly and presenting excellent sorbent properties, which allow the extraction and preconcentration of the progestogens under study.

From Rice Husk Ash to Silica-Supported Carbon Nanomaterials: Characterization and Analytical Application for Pre-Concentration of Steroid Hormones from Environmental Waters

Rice husk (RH) in the rice industry is often air-burnt to obtain energy in the form of heat and RH ash (RHA) residue. In this work, RHA was applied as a starting material to obtain silica-supported carbon nanomaterials, resulting in a new reuse of a globally produced industrial waste product, in a circular economy approach. The preparation involves ultrasound-assisted one-pot oxidation with a sulfonitric mixture followed by wet oven treatment in a closed vessel. A study of oxidation times and RHA amount/acid volume ratio led to a solid material (nC-RHA@SiO2) and a solution containing silica-supported carbon quantum dots (CQD-RHA@SiO2). TEM analyses evidenced that nC-RHA@SiO2 consists of nanoparticle aggregates, while CQD-RHA@SiO2 are carbon-coated spherical silica nanoparticles. The presence of oxygenated carbon functional groups, highlighted by XPS analyses, makes these materials suitable for a wide range of analytical applications. As the main product, nC-RHA@SiO2 was tested for its affinity towards steroid hormones. Solid-phase extractions were carried out on environmental waters for the determination of target analytes at different concentrations (10, 50, and 200 ng L−1), achieving quantitative adsorption and recoveries (RSD < 20%, n = 3). The method was successfully employed for monitoring lake, river, and wastewater treatment plant water samples collected in Northern Italy.

Recent Advances in Solid-Phase Extraction (SPE) Based on Molecularly Imprinted Polymers (MIPs) for Analysis of Hormones

Steroid hormones are active substances that are necessary in the normal functioning of all physiological activities in the body, such as sexual characteristics, metabolism, and mood control. They are also widely used as exogenous chemicals in medical and pharmaceutical applications as treatments and at times growth promoters in animal farming. The vast application of steroid hormones has resulted in them being found in different matrices, such as food, environmental, and biological samples. The presence of hormones in such matrices means that they can easily come into contact with humans and animals as exogenous compounds, resulting in abnormal concentrations that can lead to endocrine disruption. This makes their determination in different matrices a vital part of pollutant management and control. Although advances in analytical instruments are constant, it has been determined that these instruments still require some sample preparation steps to be able to determine the occurrence of pollutants in the complex matrices in which they occur. Advances are still being made in sample preparation to ensure easier, selective, and sensitive analysis of complex matrices. Molecularly imprinted polymers (MIPs) have been termed as advanced solid-phase (SPE) materials for the selective extraction and preconcentration of hormones in complex matrices. This review explores the preparation and application of MIPs for the determination of steroid hormones in different sample types.

Imprinting Technology for Effective Sorbent Fabrication: Current State-of-Art and Future Prospects

In the last 10 years, we have witnessed an extensive development of instrumental techniques in analytical methods for determination of various molecules and ions at very low concentrations. Nevertheless, the presence of interfering components of complex samples hampered the applicability of new analytical strategies. Thus, additional sample pre-treatment steps were proposed to overcome the problem. Solid sorbents were used for clean-up samples but insufficient selectivity of commercial materials limited their utility. Here, the application of molecularly imprinted polymers (MIPs) or ion-imprinted polymers (IIPs) in the separation processes have recently attracted attention due to their many advantages, such as high selectivity, robustness, and low costs of the fabrication process. Bulk or monoliths, microspheres and core-shell materials, magnetically susceptible and stir-bar imprinted materials are applicable to different modes of solid-phase extraction to determine target analytes and ions in a very complex environment such as blood, urine, soil, or food. The capability to perform a specific separation of enantiomers is a substantial advantage in clinical analysis. The ion-imprinted sorbents gained interest in trace analysis of pollutants in environmental samples. In this review, the current synthetic approaches for the preparation of MIPs and IIPs are comprehensively discussed together with a detailed characterization of respective materials. Furthermore, the use of sorbents in environmental, food, and biomedical analyses will be emphasized to point out current limits and highlight the future prospects for further development in the field.

Recent advances and applications of molecularly imprinted polymers in solid-phase extraction for real sample analysis

Sample pretreatment is essential for the analysis of complicated real samples due to their complex matrices and low analyte concentrations. Among all sample pretreatment methods, solid-phase extraction is arguably the most frequently used one. However, the majority of available solid-phase extraction adsorbents suffer from limited selectivity. Molecularly imprinted polymers are a type of tailor-made artificial antibodies and receptors with specific recognition sites for target molecules. Using molecularly imprinted polymers instead of conventional adsorbents can greatly improve the selectivity of solid-phase extraction, and therefore molecularly imprinted polymer-based solid-phase extraction has been widely applied to separation, clean up and/or preconcentration of target analytes in various kinds of real samples. In this article, after a brief introduction, the recent developments and applications of molecularly imprinted polymer-based solid-phase extraction for determination of different analytes in complicated real samples during the 2015-2020 are reviewed systematically, including the solid-phase extraction modes, molecularly imprinted adsorbent types and their preparations, and the practical applications of solid-phase extraction to various real samples (environmental, food, biological, and pharmaceutical samples). Finally, the challenges and opportunities of using molecularly imprinted polymer-based solid-phase extraction for real sample analysis are discussed.

Toxic effects of bisphenol A and its analogues on cyanobacteria Anabaena variabilis and Microcystis aeruginosa

In the last decades, the use of bisphenol A has attracted global attention resulting from its actions as an endocrine disrupting compound. In this regard, various bisphenol analogues have been manufactured as a replacement for this compound in consumer products. As a result of the high production volumes, different bisphenol analogues are entered into the terrestrial and aquatic environment, which consequently leads to their increasing contamination and may pose serious risk to organisms. Nevertheless, only few studies have reported on the toxic effect of bisphenol analogues on phytoplankton. Therefore, in this study, the anticyanobacterial activity of six bisphenol analogues and their mixture were investigated for the first time. Bisphenol AF, bisphenol B and bisphenol C (14 d, EC₅₀ 12.88-54.87 mg L^-1) exhibit more toxic effect to both tested species in comparison to bisphenol A (14 d, EC₅₀ 55.27-78.96 mg L^-1). Moreover, data show that mixture of bisphenol analogues (14 d, EC₅₀ 32.32-60.88 mg L^-1) exhibit toxic effect similar to or even stronger than that of bisphenol A. The toxic effect of bisphenol analogues, singly and in combination on the growth of both cyanobacteria species was arranged in the following order: bisphenol AF > bisphenol C> bisphenol B> bisphenol A> bisphenol E> bisphenol BP and bisphenol B> bisphenol AF > bisphenol C> bisphenol A> bisphenol E> bisphenol BP for Anabaena variabilis and Microcystis aeruginosa, respectively. This research aims to assure a basic understanding of the toxic effects of bisphenol analogues on cyanobacteria and provides a more comprehensive view on environmental risk assessment.

Detection, occurrence, and fate of emerging contaminants in agricultural environments (2020)

A review of 79 papers published in 2019 is presented. The topics ranged from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, antibiotics, anthelmintics, and engineered nanomaterials in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Antibiotics in Agroecosystems, Pharmaceutical Fate and Occurrence, Anthelmintics and Engineered Nanomaterials. PRACTITIONER POINTS: New research describes innovative new techniques for emerging contaminant detection in agricultural settings Newer classes of contaminants include human and veterinary pharmaceuticals Research in nanomaterials show that these also occur in agricultural environments and will likely be topics of future work.

The biomimetic detection of progesterone by novel bifunctional group monomer based molecularly imprinted polymers prepared in UV light

A novel itaconic acid based progesterone imprinted biosensor was prepared via a reversible addition chain transfer mechanism and surface plasmon resonance.