A new carbon-based magnetic material for the dispersive solid-phase extraction of UV filters from water samples before liquid chromatography–tandem mass spectrometry analysis

On-site extraction of benzophenones from swimming pool water using hybrid tapes based on the integration of hydrophilic-lipophilic balance microparticles and an outer magnetic nanometric domain

An on-site extraction device is presented consisting of scotch tape modified with concentric domains of micrometric hydrophilic-lipophilic balance (HLB) particles surrounded by a ring of nanometric magnetic ones. On the one hand, HLB microparticles are readily available at the surface of the tape, exposed to interact with the target analytes, being responsible for the extraction capacity of the sorptive phase. On the other hand, the presence of magnetic nanoparticles enables the attachment of the modified tape onto a metallic screw via a magnet, which is then coupled to a wireless drill, enabling the stirring of the microextraction device. Both are simply fixed to the cost-effective, flexible, and versatile support, i.e., scotch tape, owing to their adhesive properties. The microextraction device has been applied to the determination of six benzophenones in swimming pool water samples. The variables that may affect the extraction process have been evaluated. Under the optimum conditions and using liquid chromatography-tandem mass spectrometry as the instrumental technique, the method provided a limit of detection of 0.03 µg L-1. The intra-day precision, evaluated at three different concentration levels and expressed as relative standard deviation, was lower than 10%, which also comprises the variability within single-use sorptive tapes. The accuracy, calculated with spiked samples and expressed as relative recovery, ranged from 71 to 138%. The method was applied to the analysis of swimming pool water, revealing the presence of such compounds.

Microextraction Techniques for Sample Preparation of Amphetamines in Urine: A Comprehensive Review

Psychological disorders and dramatic social problems are serious concerns regarding the abuse of amphetamine and its stimulant derivatives worldwide. Consumers of such drugs experience great euphoria along with serious health problems. Determination and quantification of amphetamine-type stimulants are indispensable skills for clinical and forensic laboratories. Analysis of low drug doses in bio-matrices necessitates applications of simple and also effective preparation steps. The preparation procedures not only eliminate adverse matrix effects, but also provide reasonable clean-up and pre-concentration benefits. The current review presents different methods used for sample preparation of amphetamines from urine as the most frequently used biological matrix. The advantages and limitations of various sample preparation methods were discussed focusing on the miniaturized methods.

Prevalence of selected UV filter compounds in Biscayne National Park

This research was carried out in order to assess a baseline occurrence in Biscayne National Park, Florida, of four organic contaminants: the UV filters oxybenzone, dioxybenzone, and benzophenone, as well as the topical pain reliever benzocaine. A total of 35 samples were taken from five locations within the park, four near barrier islands, and one at a coral reef. Analyses were carried out using liquid chromatography coupled to high-resolution mass spectrometry. Oxybenzone was detected in 26% of samples from the park at concentrations up to 31 ng/L. Benzophenone was detected in 49% of samples from the park at concentrations up to 131 ng/L. Benzocaine and dioxybenzone were not detected in any of the samples.

Self-assembled Fe3O4-NH2 @g-C3N4 composite for magnetic solid-phase extraction of benzophenones in sea water and lake water coupled with LC-MS/MS determination

Magnetic solid-phase extraction (MSPE) was developed based on a well-designed Fe3O4-NH2 @g-C3N4 nanocomposite as sorbent for a mixture of six benzophenones (BPs) in environmental water samples. The composite fabricated via in-situ self-assembled g-C3N4 shell with homogeneous polymerization of cyanuric chloride and cyanuric acid on Fe3O4-NH2 core. While high adsorption capacity was derived from g-C3N4 via hydrophobic, π-π and hydrogen bonding interactions to the targets, the fast magnetic separation was realized with Fe3O4 core for less solvent consumption. In combination with LC-MS/MS, the Fe3O4-NH2 @g-C3N4 sorbent minimized the interfering components, reduced the matrix effects, and provided the enrichment factors of 121-150 for six BPs with relative standard deviations ≤ 9.7% even after 20 times extraction-desorption cycles. The present method gave the detection limits of 0.3-2.5 ng/L for six BPs with the linear ranges of 1.0-2000 ng/L, and the recoveries of 84.6%-104% in sea water and 86.2%-107% in lake water samples. Thus, the Fe3O4-NH2 @g-C3N4-based MSPE coupled with LC-MS/MS method provided a convenient, efficient, and reliable alternative to monitor trace BPs in environmental water samples.

A magnetic molecularly imprinted polymer based on an eco-friendly deep eutectic solvent for the selective recognition of dichlorodiphenyl trichloroethane and its degradation products in fruits and vegetables

A new magnetic molecularly imprinted polymer was successfully synthesized using a ternary deep eutectic solvent derived from caffeic acid-choline chloride-formic acid as a functional monomer, thymol-menthol deep eutectic solvent as a template, ethylene glycol dimethacrylate as a cross-linker, potassium peroxodisulfate as an initiator, and aqueous ethanol solution (90% (v/v)) as a porogen. The synthesized material was characterized and applied for magnetic solid-phase extraction of dichlorodiphenyl trichloroethane and its degradation products. Optimization of the extraction condition was carried out using the central composite design and response surface methodology. The good analytical performance of magnetic solid phase extraction/gas chromatography‒mass spectrometry using the proposed adsorbent shows a wide linear range of 0.07-500 ng g-1 with R2 greater than 0.992. Low detection limits and quantitation limits were observed in the ranges of 0.01-2.00 ng g-1 and 0.07-2.50 ng g-1, respectively. The precisions shown in terms of relative standard deviations were lower than 7.0% for intraday (n=5) and 8.6% for interday (n=5 × 3) experiments. The proposed method was applied for preconcentration and determination of dichlorodiphenyl trichloroethane and its degradation products in fruit and vegetable samples. The satisfactory recoveries of the real samples at three spiked concentrations were obtained in the range of 79.1%-110.9% with RSDs lower than 7.5%. The findings highlight the importance of developing efficient sorbents for the enrichment of persistent organic pollutants in food matrices.

The environmental sources of benzophenones: Distribution, pretreatment, analysis and removal techniques

Benzophenones (BPs) have wide practical applications in real human life due to its presence in personal care products, UV-filters, drugs, food packaging bags, etc. It enters the wastewater by daily routine activities such as showering, impacting the whole aquatic system, then posing a threat to human health. Due to this fact, the monitoring and removal of BPs in the environment is quite important. In the past decade, various novel analytical and removal techniques have been developed for the determination of BPs in environmental samples including wastewater, municipal landfill leachate, sewage sludge, and aquatic plants. This review provides a critical summary and comparison of the available cutting-edge pretreatment, determination and removal techniques of BPs in environment. It also focuses on novel materials and techniques in keeping with the concept of "green chemistry", and describes on challenges associated with the analysis of BPs, removal technologies, suggesting future development strategies.

Magnetic graphitized carbon black based on crystal growth method combined with high-resolution mass spectrometry for screening of 300 pesticide residues in Radix Codonopsis and Angelica sinensis

In this study, a high-throughput method for analyzing 300 pesticide residues in Radix Codonopsis and Angelica sinensis was established by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) using iron tetroxide loaded graphitized carbon black magnetic nanomaterial (GCB/Fe₃O₄) as the purification material. It was optimized that saturated salt water and 1 % acetate acetonitrile were used as the extraction solution, then the supernatant was purified with 2 g anhydrous CaCl₂ and 300 mg GCB/Fe₃O₄. As a result, 300 pesticides in Radix Codonopsis and 260 in Angelica sinensis achieved satisfactory results. The limits of quantification of 91 % and 84 % of the pesticides in Radix Codonopsis and Angelica sinensis reached 10 μg/kg, respectively. The matrix-matched standard curves ranging from 10 to 200 μg/kg were established with correlation coefficients (R) above 0.99. The pesticides meeting SANTE/12682/2021 accounted for 91.3 %, 98.3 %, 100.0 % and 83.8 %, 97.3, 100.0 % of the total pesticides added in Radix Codonopsis and Angelica sinensis respectively, which were spiked at 10, 20,100 μg/kg. The technique was applied to screen 20 batches of Radix Codonopsis and Angelica sinensis. Five pesticides were detected, three of which were prohibited according to the Chinese Pharmacopoeia (2020 Edition). The experimental results showed that GCB/Fe₃O₄ coupled with anhydrous CaCl₂ exhibited good adsorption performance and could be used for sample pretreatment of various pesticide residues in Radix Codonopsis and Angelica sinensis. Compared with the reported methods for determining pesticides in traditional Chinese medicine (TCM), the proposed method has the advantage of less time-consuming in the clean-up procedure. Furthermore, as a case study on root TCM, this approach may serve as a reference for other TCM.

Benzophenones in the Environment: Occurrence, Fate and Sample Preparation in the Analysis

The ubiquitous presence of emerging contaminants in the environment is an issue of great concern. Notably, for some of them, no established regulation exists. Benzophenones are listed as emerging contaminants, which have been identified in the environment as well as in human fluids, such as urine, placenta, and breast milk. Their accumulation and stability in the environment, combined with the revealed adverse effects on ecosystems including endocrine, reproductive, and other disorders, have triggered significant interest for research. Benzophenones should be extracted from environmental samples and determined for environmental-monitoring purposes to assess their presence and possible dangers. Numerous sample preparation methods for benzophenones in environmental matrices and industrial effluents have been proposed and their detection in more complex matrices, such as fish and sludges, has also been reported. These methods range from classical to more state-of-the-art methods, such as solid-phase extraction, dispersive SPE, LLE, SBSE, etc., and the analysis is mostly completed with liquid chromatography, using several detection modes. This review critically outlines sample preparation methods that have been proposed to date, for the extraction of benzophenones from simple and complex environmental matrices and for cleaning up sample extracts to eliminate potential interfering components that coexist therein. Moreover, it provides a brief overview of their occurrence, fate, and toxicity.

Magnetic Nanoparticle-Based Dispersive Solid-Phase Microextraction of Three UV Blockers Prior to Their Determination by HPLC-DAD

The need for proper handling of environmental samples is significant, owing to their environmental effects on both humans and animals, as well as their immediate surroundings. In the current study, magnetic nanoparticle-based dispersive solid-phase microextraction was combined with high-performance liquid chromatography using a diode array as the detector (HPLC-DAD) for both the separation and determination of three different UV blockers, namely octocrylene, ethylhexyl methoxycinnamate, and avobenzone. The optimum conditions for the extraction were found to be as follows: Stearic acid magnetic nanoparticles (20 mg) as the sorbent, acetonitrile (100 µL) as the eluent, as well as a sample pH of 2.50, adsorption and desorption time of 1.0 min, with a 3.0 mL sample volume. The limits of detection were as low as 0.05 µg mL-1. The coefficient of determination (R2) was above 0.9950, while the percentages of relative recoveries (%RR) were between 81.2 and 112% for the three UV blockers from the environmental water samples and sunscreen products.

Greenness of magnetic nanomaterials in miniaturized extraction techniques: A review

Green analytical chemistry principles should be followed, as much as possible, and particularly during the development of analytical sample preparation methods. In the past few years, outstanding materials such as ionic liquids, metal-organic frameworks, carbonaceous materials, molecularly imprinted materials, and many others, have been introduced in a wide variety of miniaturized techniques in order to reduce the amount of solvents and sorbents required during the analytical sample preparation step while pursuing more efficient extraction methods. Among them, magnetic nanomaterials (MNMs) have gained special attention due to their versatile properties. Mainly, their ability to be separated from the sample matrix using an external magnetic field (thus enormously simplifying the entire process) and their easy combination with other materials, which implies the inclusion of a countless number of different functionalities, highly specific in some cases. Therefore, MNMs can be used as sorbents or as magnetic support for other materials which do not have magnetic properties, the latter permiting their combination with novel materials. The greenness of these magnetic sorbents in miniaturized extractions techniques is generally demonstrated in terms of their ease of separation and amount of sorbent required, while the nature of the material itself is left unnoticed. However, the synthesis of MNMs is not always as green as their applications, and the resulting MNMs are not always as safe as desired. Is the analytical sample preparation field ready for using green magnetic nanomaterials? This review offers an overview, from a green analytical chemistry perspective, of the current state of the use of MNMs as sorbents in microextraction strategies, their preparation, and the analytical performance offered, together with a critical discussion on where efforts should go.

Use of Nanomaterial-Based (Micro)Extraction Techniques for the Determination of Cosmetic-Related Compounds

The high consumer demand for cosmetic products has caused the authorities and the industry to require rigorous analytical controls to assure their safety and efficacy. Thus, the determination of prohibited compounds that could be present at trace level due to unintended causes is increasingly important. Furthermore, some cosmetic ingredients can be percutaneously absorbed, further metabolized and eventually excreted or bioaccumulated. Either the parent compound and/or their metabolites can cause adverse health effects even at trace level. Moreover, due to the increasing use of cosmetics, some of their ingredients have reached the environment, where they are accumulated causing harmful effects in the flora and fauna at trace levels. To this regard, the development of sensitive analytical methods to determine these cosmetic-related compounds either for cosmetic control, for percutaneous absorption studies or for environmental surveillance monitoring is of high interest. In this sense, (micro)extraction techniques based on nanomaterials as extraction phase have attracted attention during the last years, since they allow to reach the desired selectivity. The aim of this review is to provide a compilation of those nanomaterial-based (micro)extraction techniques for the determination of cosmetic-related compounds in cosmetic, biological and/or environmental samples spanning from the first attempt in 2010 to the present.

Magnetic Graphene Oxide Composite for the Microextraction and Determination of Benzophenones in Water Samples

Magnetite nanoparticles (Fe₃O₄) functionalized with graphene oxide (GO) have been synthesized through a silanization process of the magnetic nanoparticles with tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane and further coupling of GO. The synthesized nanomaterials have been characterized by several techniques, such as transmission electron microscopy (TEM), and infrared and Raman spectroscopy, which enabled the evaluation of the different steps of the functionalization process. The hybrid nanomaterial has been employed for the extraction of five benzophenones (benzophenone-1, benzophenone-3, 4-hydroxybenzophenone, benzophenone-6 and benzophenone-8) in aqueous samples by dispersive micro-solid phase extraction, combining the magnetic properties of magnetite nanoparticles with the excellent sorption capacity of graphene oxide via hydrophobic interactions with the analytes. The subsequent separation and quantification of the analytes was performed by liquid chromatography with tandem mass spectrometric detection, achieving limits of detection (LODs) in the range 2.5 to 8.2 μg·L^-1, with relative standard deviations ranging from 1.3-9.8% and relative recovering in the range 86 to 105%. Positive swimming pool water samples analysed following the developed method revealed the presence of benzophenones in from 14.3 to 39 μg·L^-1.