Determination of ultraviolet filter compounds in environmental water samples using membrane-protected micro-solid-phase extraction

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.

Fe3O4@UiO-66-NH2 based on magnetic solid phase extraction for determination of organic UV filters in environmental water samples

In this work, a nanocomposite structured magnetic metal-organic framework named as Fe3O4@UiO-66-NH2 was prepared via a simple hydrothermal approach. The as-mentioned nanocomposite was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and the Brunauer-Emmett-Teller (BET) techniques. Using the Fe3O4@UiO-66-NH2 as a nanosorbent, an easy and highly effective approach was developed to preconcentrate nine organic UV filters before gas chromatography-mass spectrometry (GC-MS) analysis. Different conditions influencing the extraction efficiency encompassing the sorbent amount, nature and volume of desorption solvent, desorption time, pH of the sample, and extraction time, were examined. Under the optimal experimental parameters, the Fe3O4@UiO-66-NH2-based magnetic solid phase extraction and GC-MS (MSPE-GC-MS) demonstrated linearity in the range of 0.03-1500 ng/L (R2 ≥ 0.9974) and the reproducibility, expressed as RSD, was ≤7.5%. The limits of detection ranged between 0.01 and 0.07 ng/L and limits of quantification were in the range of 0.03-0.4 ng/L. Finally, the suggested approach was satisfactorily utilized to determine nine organic UV filters in different water samples (analytical recoveries between 86.5% and 104.2%).

Trends in Innovations and Recent Advances in Membrane Protected Extraction Techniques for Organics in Complex Samples

Membrane protected extraction is an ongoing innovation for isolation and pre-concentration of analytes from complex samples. The extraction process, clean-up and pre-concentration of analytes occur in a single step. The inclusion of solid sorbents such as molecularly imprinted polymers (MIPs) after membrane extraction ensures that selective double extraction occurs in a single step. The first step involves selective extraction using the membrane and diffused analytes are trapped on the solid sorbent enclosed in the membrane. No further clean-up is required even for very dirty samples like plant extracts and wastewaters samples. Sample clean-up occurs during extraction in the first process and not as additional step since matrix components are prevented from trapping on the sorbent. This can be referred to as prevention is better than cure approach. In this work, the analytical methods that employed membrane protected extraction for various organics such as pesticides, polycyclic aromatic hydrocarbons, and pharmaceuticals are reviewed. The designs of these analytical methods, their applications, advantages and drawbacks are discussed in this review. Literature suggests that the introduction of solid sorbents in membrane creates the much-needed synergy in selectivity. Previous reviews focused on membrane combinations with MIPs while discussing micro-solid-phase extraction. The scope of this review was broadened to include other sample preparation aspects such as membrane protected stir bar solvent extraction and membrane protected solid-phase microextraction. In addition, novel sample preparation methods for solid samples which include Soxhlet membrane protected molecular imprinted solid phase extraction and membrane protected ultra sound assisted extracted are discussed.

Investigation of simultaneous multiple UV filters degradation efficiency of plasmonic Ag@AgCl photocatalyst in the aquatic environment under sunlight irradiation

UV filters as an important class of emerging organic pollutants are continuously released into and transported between the aquatic environments. So, the removal of these compounds from aquatic environments is of great importance. This study was conducted to evaluate the simultaneous photodegradation of three widely used UV filter compounds (4-methylbenzylidene camphor, 2-ethylhexyl 4-(dimethylamino) benzoate, ethylhexyl methoxycinnamate), in an aqueous environment under sunlight and Ag@AgCl photocatalyst integrated with plasmonic effect. The plasmonic Ag@AgCl nanocomposite was constructed via photochemical conversion and photoreduction. The enhanced photocatalytic performance can be attributed to the surface plasmon resonance effect of the silver nanoparticles and the hybrid effect caused by AgCl. For the monitoring of the target compounds' degradation before and after photodegradation, an optimized method based on membrane-protected micro-solid-phase extraction coupled with gas chromatography-mass spectrometry (GC-MS) was employed. The simultaneous degradation of selected UV filters was also further investigated in contaminated real samples (river water) and the results showed that the matrix constituents could diminish the photocatalytic degradation efficiency.

Investigations on the uptake and transformation of sunscreen ingredients in duckweed (Lemna gibba) and Cyperus alternifolius using high-performance liquid chromatography drift-tube ion-mobility quadrupole time-of-flight mass spectrometry

The uptake, translocation and transformation of three UV-blockers commonly employed in sunscreens, namely avobenzone, octocrylene and octisalate from water by Lemna gibba and Cyperus alternifolius was investigated. Reversed phase high performance liquid chromatography coupled to drift-tube ion-mobility quadrupole time-of-flight mass spectrometry was used for analyzing the extracts from the selected plants after incubation with the UV-blockers for one week. For avobenzone several transformation products resulting from hydroxylation, demethylation and oxidation of the parent molecule could be identified by measuring accurate mass, performing MS/MS experiments and by determining their drift-tube collision cross sections employing nitrogen as drift gas. In addition, the plants were subjected to two commercially available sunscreens, providing similar results to those obtained for the standard solutions of the UV-blockers. Finally, a kinetic study on the uptake and transformation of avobenzone, octocrylene and octisalate was conducted over a period of 216 h, revealing that the UV-filters were mostly present in their parent form and only to a smaller part converted into transformation products.