Determination Of Ultraviolet Filters Research Articles

Synthesis of a magnetic covalent organic framework for extraction and separation of ultraviolet filters in beverage samples

In this study, a novel magnetic covalent organic framework (Fe3O4@TAPB-BTT) was successfully synthesized under mild conditions. The prepared magnetic COF exhibited large surface area (876.3 m2 g−1), porous feature as well as sizeable π-conjugated network structure. Due to the above advantages, Fe3O4@TAPB-BTT showed good adsorptive performance for ultraviolet (UV) filters with adsorption capacities ranging from 80.8 to 120.1 mg g−1. Then the adsorbent was applied to magnetic solid phase extraction (MSPE) of UV filters in beverage samples, followed by UHPLC-MS/MS analysis. The established method showed good accuracy, precision, and reproducibility with satisfactory recoveries (76.9–95.6 %), low limits of detection (0.001–0.15 µg/L), and low relative standard deviations (<9.8 %). Besides, the adsorbent can be reutilized at least ten times, demonstrating satisfactory reusability. This work provided an effective method for the analysis and determination of UV filters in drinks.

Fabrication and application of polyaniline/titanium dioxide nanotube solid phase microextraction fiber

A novel solid phase microextraction fiber of polyaniline coated titania composite nanotube (PANI@TiO2NTs/Ti) array was fabricated on a titanium wire by in situ oxidation. The effects of the inorganic acid medium, aniline concentration, and oxidation voltage on the electropolymerization of aniline were discussed. The best forming conditions for the composite fiber obtained by analyzing the surface morphology and composition of the fibers were as follows:electrolyte composing, 0.5 mol/L aniline-1 mol/L H2SO4; electropolymerization, 10 V for 60 min. The developed fibers were used in conjunction with high performance liquid chromatography for the extraction and determination of ultraviolet filters in samples, and the extraction conditions optimized were as follows:extraction time 40 min, desorption time 4 min, extraction temperature 40℃, stirring rate 600 r/min. The average recoveries of the target analytes spiked in real samples ranged from 78.2% to 118%, and the relative standard deviations ranged from 4.4% to 8.9%. The developed method is simple, rapid, and accurate, and it is suitable for the sensitive determination of UV filters in environmental water samples.

Determination of ultraviolet filters in human nails using an acid sample digestion followed by ultra-high performance liquid chromatography–mass spectrometry analysis

Ultraviolet filters (UV-filters) are specific chemicals that absorb and reflect UVA and UVB radiation from the sun. They are regularly used in sunscreens and in other personal care products (PCPs), and in products like plastics, adhesives, toys, or furniture finishes. This work develops and validates a new method to determine concentrations of UV-filters (BP-1, BP-2, BP-3, BP-6, BP-8, 4-OH-BP, THB, AVB) in human nail samples. Nails are easily available and are considered to be suitable indicators of cumulative and continued exposure to harmful chemicals. The treatment of nail samples includes microwave assisted digestion/extraction (MAE) in a methanolic solution of o-phosphoric acid (0.05 mol L−1) followed by analyte determination using ultra-high performance liquid chromatography–mass spectrometry (UHPLC–MS/MS) in multiple reaction monitoring mode. The analytes were separated in less than 10 min. The digestion procedure was optimized using multivariate techniques. Matrix-matched calibration with a pig hoof matrix was used for validating the method. A study of accuracy with spiked blank samples was also conducted. The calculated detection limits varied between 0.2 and 1.5 ng g−1, and quantification limits between 1.0 and 5.0 ng g−1. The trueness of the method was an estimation of the recovery, which was between 90.2% and 112.2%; with an estimated precision (relative standard deviation, % RSD) lower than 12.3% for all UV-filters. Nail samples were obtained from 22 volunteers (male and female). The results showed that BP-1 and BP-3 mainly bioaccumulate in human nails.

Robust Fabrication of Novel Silica Nanosheets on Titanium Fibers for the Selective and Sensitive Determination of Ultraviolet Filters in Environmental Waters by Solid-Phase Microextraction

A novel silica nanosheet coating was fabricated on a titanium (Ti) fiber substrate by electrophoretic deposition followed by annealing. Prior to the electrophoretic deposition, titania nanowire arrays were grown in-situ on the titanium wires by a hydrothermal process in alkaline solution and used as the active support for the subsequent deposition of the silica coatings. After annealing at 550 °C, the homogeneous silica nanosheets were formed on the titania nanowires coated titanium fiber. The fabricated fiber has controllable preparation reproducibility and long recycling stability. The extraction performance of the resulting coating was investigated using typical aromatic compounds as model analytes coupled to high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Excellent extraction selectivity and capability were demonstrated for the ultraviolet filters. Under the optimized extraction conditions for the analytes, good linearity was achieved across the concentration range from 0.02 to 400 μg·L−1 with correlation coefficients above 0.999 and limits of detection from 0.004 to 0.059 μg·L−1. Relative standard deviations below 7.3% were obtained for the determination of ultraviolet filters with the single fiber. The developed method was applied to the selective enrichment and sensitive determination of the target ultraviolet filters in real water samples with relative recoveries from 83.6% to 104%.

Determination of Ultraviolet Filters in Domestic Wastewater by LC–MS Coupled with Polydopamine-Based Magnetic Solid-Phase Extraction and Isotope-Coded Derivatization

A selective and accurate liquid chromatography–mass spectrometry (LC-MS) method based on magnetic solid-phase extraction (MSPE) and isotope-coded derivatization was developed and validated. The magnetic polydopamine (Fe3O4@PDA) was prepared as sorbent for enrichment of ten ultraviolet (UV) filters from domestic wastewater samples. The obtained extract and standards were labeled by a pair of isotope-coded derivatization reagents d0-/d3-10-methylacridone-2-sulfonyl chloride (d0-/d3-MASC), respectively. The quantification of UV filters was achieved by calculation of the peak area ratios of d0-MASC/d3-MASC-labeled derivatives. The isotope-coded derivatization strategy was confirmed to be effective in reducing matrix effect and improving sensitivity. Excellent linearity is established with the correlation coefficients > 0.9922. The limits of detection (LODs) were in the range of 0.056–0.128 µg L−1, and the limits of quantitation (LOQs) were in the range of 0.193–0.315 µg L−1. The developed method has been successfully applied to the quantification of UV filters in domestic wastewater samples with recoveries ranging from 95.6 to 103.6%.

Expanding the application of stir bar sorptive-dispersive microextraction approach to solid matrices: Determination of ultraviolet filters in coastal sand samples

This work describes a new method for the determination of organic compounds in solid samples based on the equilibrium desorption of the analytes in an aqueous phase followed by stir bar sorptive-dispersive microextraction (SBSDME). Sand samples, contaminated with UV filters due to bathing and recreational activities, were dispersed in an aqueous medium by using a coated stir bar with CoFe2O4@oleic acid magnetic nanoparticles. The UV filters were physically desorbed from the surface of the sand particles and rapidly adsorbed on the hydrophobic coating of the nanoparticles, which were retrieved by means of their magnetism after stopping the stirring. In this manner, both preconcentration of the analytes and clean-up were simultaneously accomplished without the requirement of any additional sample preparation steps. After extraction, the analytes were desorbed in ethanol and then analyzed by gas chromatography-mass spectrometry (GC–MS). The main variables involved in the extraction process (i.e., sorbent amount, extraction time, pH and ionic strength) were studied to provide the best extraction efficiencies and maximum enrichment factors. Under the selected conditions, the figures of merit of the proposed method were evaluated providing limits of detection in the low ng g−1 range, enrichment factors between 23 and 80, and relative standard deviations (RSD%) below 14% for all the target analytes. Matrix effects were observed in real costal sand samples and thus standard addition calibration was employed for quantification. The method was successfully applied to the analysis of UV filters in several coastal sand samples of different origin. This work expands the analytical potential of the novel SBSDME approach to the determination of organic compounds in solid matrices.

Determination of UV filters in high ionic strength sample solutions using matrix-compatible coatings for solid-phase microextraction

A double-confined polymeric ionic liquid (PIL) sorbent coating was fabricated for the determination of nine ultraviolet (UV) filters in sample solutions containing high salt content by direct immersion solid-phase microextraction (DI-SPME) coupled to high-performance liquid chromatography (HPLC). The IL monomer and crosslinker cations and anions, namely, 1-vinyl-3-decylimidazolium styrenesulfonate ([VImC10][SS]) and 1,12-di(3-vinylbenzylimidazolium) dodecane distyrenesulfonate ([(VBIm)2C12] 2[SS]), were co-polymerized to create a highly stable sorbent coating which allowed for up to 120 direct-immersion extractions in 25% NaCl (w/v) solution without a decrease in its extraction capability. Extraction and desorption parameters such as desorption solvent, agitation rate, extraction time, desorption solvent volume, and desorption time were evaluated and optimized. The analytical performance of the styrenesulfonate anion-based PIL fiber, PIL fiber containing chloride anions, and a commercially available polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber were compared. Coefficients of determination (R2) for the styrenesulfonate anion-based PIL fiber ranged from 0.995 to 0.999 and the limits of detection (LODs) varied from 0.1 to 5 µg L−1. The developed method was successfully applied in real water samples including tap, pool, and lake water, and acceptable relative recovery values were obtained. The lifetime of the PIL fiber containing chloride anions as well as the PDMS/DVB fiber were considerably shorter than the PIL fiber containing the styrenesulfonate anion, with both fibers showing a notable decrease in reproducibility and significant damage to the sorbent coating surface after 40 and 70 extractions, respectively. The R2 values for the chloride anion containing PIL fiber were at or higher than 0.991 with LODs ranging from 0.5 to 5 µg L−1. For the PDMS/DVB fiber, R2 values ranged from 0.992 to 0.999 and LODs were found to be as low as 0.2 µg L−1 and as high as 5 µg L−1.

Expanding the use of polymeric ionic liquids in headspace solid-phase microextraction: Determination of ultraviolet filters in water samples

Three crosslinked polymeric ionic liquid (PIL) sorbent coatings were used in headspace solid-phase microextraction for the determination of a group of ultraviolet filters. The developed crosslinked PIL-based materials include two polycations and a double confined PIL. The method, in combination with gas chromatography-mass spectrometry, is simple, solvent free, and does not require of any derivatization step. After proper optimization of the methodologies with each developed fiber, the analytical performance was compared with a commercial polyacrylate fiber. A study of the normalized calibration slopes, obtained by dividing the calibration slope of each analyte by the coating volume, revealed that the crosslinked fibers can be used as alternatives to commercial fibers for the determination of the selected group of compounds. In particular, the coating nature of the PIL containing the 1-vinylbenzyl-3-hexadecylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL as monomer and the 1,12-di(3-vinylbenzylimidazolium)dodecane bis[(trifluoromethyl)sulfonyl]imide IL as crosslinker is the most suitable for the extraction of the selected compounds despite their coating volume, being 3.6 times lower than the commercial polyacrylate fiber. For this fiber, wide linear ranges, correlation coefficients higher than 0.990, limits of detection ranging from 2.8 ng L−1 to 26 ng L−1 and relative standard deviations ranging from 2.5 to 15% were achieved. Finally, all proposed PIL-based fibers were applied towards the analysis of tap water, pool water and lake water, with the majority of the ultraviolet filters being detected and quantified in the last two types of samples.

Deep eutectic solvent-based ultrasound-assisted dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the determination of ultraviolet filters in water samples

In the present study, a simple and rapid sample preparation method designated ultrasound-assisted dispersive liquid-liquid microextraction based on a deep eutectic solvent (DES) followed by high-performance liquid chromatography with ultraviolet (UV) detection (HPLC-UVD) was developed for the extraction and determination of UV filters from water samples. The model analytes were 2,4-dihydroxybenzophenone (BP-1), benzophenone (BP) and 2-hydroxy-4-methoxybenzophenone (BP-3). The hydrophobic DES was prepared by mixing trioctylmethylammonium chloride (TAC) and decanoic acid (DecA). Various influencing factors (selection of the extractant, amount of DES, ultrasound duration, salt addition, sample volume, sample pH, centrifuge rate and duration) on UV filter recovery were systematically investigated. Under optimal conditions, the proposed method provided good recoveries in the range of 90.2–103.5% and relative standard deviations (inter-day and intra-day precision, n=5) below 5.9%. The enrichment factors for the analytes ranged from 67 to 76. The limits of detection varied from 0.15 to 0.30ngmL−1, depending on the analytes. The linearities were between 0.5 and 500ngmL−1 for BP-1 and BP and between 1 and 500ngmL−1 for BP-3, with coefficients of determination greater than 0.99. Finally, the proposed method was applied to the determination of UV filters in swimming pool and river water samples, and acceptable relative recoveries ranging from 82.1 to 106.5% were obtained.

Determination of ultraviolet filters in bathing waters by stir bar sorptive–dispersive microextraction coupled to thermal desorption–gas chromatography–mass spectrometry

In this work, a new approach that combines the advantages of stir bar sorptive extraction (SBSE) and dispersive solid phase extraction (DSPE), i.e. stir bar sorptive–dispersive microextraction (SBSDµE), is employed as enrichment and clean-up technique for the sensitive determination of eight lipophilic UV filters in water samples. The extraction is accomplished using a neodymium stir bar magnetically coated with oleic acid-coated cobalt ferrite magnetic nanoparticles (MNPs) as sorbent material, which are detached and dispersed into the solution at high stirring rate. When stirring is stopped, MNPs are magnetically retrieved onto the stir bar, which is subjected to thermal desorption (TD) to release the analytes into the gas chromatography–mass spectrometry (GC–MS) system. The SBSDµE approach allows for lower extraction time than SBSE and easier post-extraction treatment than DSPE, while TD allows for an effective and solvent-free injection of the entire quantity of desorbed analytes into GC–MS, and thus achieving a high sensitivity. The main parameters involved in TD, as well as the extraction time, were evaluated. Under the optimized conditions, the method was successfully validated showing good linearity, limits of detection and quantification in the low ngL−1 range and good intra- and inter-day repeatability (RSD<12%). This accurate and sensitive analytical method was applied to the determination of trace amounts of UV filters in three bathing water samples (river, sea and swimming pool) with satisfactory relative recovery values (80–116%).

In situ growth and phenyl functionalization of titania nanoparticles coating for solid-phase microextraction of ultraviolet filters in environmental water samples followed by high performance liquid chromatography–UV detection

Based on TiO2-nanoparticles coating fabricated by a one-step anodization method on titanium wire substrate, a novel phenyl functionalized solid-phase microextraction (SPME) fiber coating was prepared by simple and rapid in situ chemical assembling technique between the fiber surface titanol groups and trichlorophenylsilane reaction. The as-fabricated fiber exhibited good extraction capability for some UV filters and was employed to determine the ultraviolet (UV) filters in combination with high performance liquid chromatography–UV detection (HPLC–UV). The main parameters affecting extraction performance were investigated and optimized. Under the optimized conditions, the developed method was applied to detect several UV filters at trace concentration levels with only 8mL of sample volume. They were determined in the range from 0.005 to 25μgL−1 with detection limits (S/N=3) from 0.1 to 50ngL−1. The relative standard deviations (RSDs) for single fiber repeatability varied from 4.6 to 6.5% (n=5) and fiber-to-fiber reproducibility (n=5) ranged from 5.5 to 9.1%. The linear ranges spanned two-four magnitudes with correlation coefficients above 0.9990. Five real water samples including four Yellow River water samples and one rain water sample were determined sensitively with good recoveries ranging from 86.2 to 105.5%. The functionalized fiber coating performed good reproducible manner, high mechanical strength, good stability and long service life. Moreover, this study proposed an efficient sample pretreatment method for the determination of UV filters from environmental water samples.

Concentration and Determination of Ultraviolet Filters in Environmental Water Samples with Ionic Liquid-Dispersive Liquid-Liquid Microextraction Followed by High Performance Liquid Chromatography

Concentration and Determination of Ultraviolet Filters in Environmental Water Samples with Ionic Liquid-Dispersive Liquid-Liquid Microextraction Followed by High Performance Liquid Chromatography

Determination of ultraviolet filters in environmental aqueous samples by dispersive liquid-liquid microextraction with online derivatization-gas chromatography-mass spectrometry

A method of dispersive liquid-liquid microextraction (DLLME) combined with online derivatization-gas chromatography-mass spectrometry (GC-MS) was developed for the determination of benzophenone-type ultraviolet (UV) filers (BPs) in environmental aqueous samples. It is found that the online derivatization was superior to the off-line derivatization with its simplicity, high reaction efficiency and less consumption of potential poisonous reagents. The influential factors for online derivatization, including the temperature of the injection port, the splitless time, the proportion of derivatization reagent and sample solution, were initially optimized. In addition, the influential factors for DLLME, including the type of the extractant and dispersing solvent, the proportion of the extractant and the dispersing solvent, the volume of sample solution, the pH and the salt concentration of the sample solution were individually optimized in detail. Under the optimized derivatization and DLLME conditions, the limits of detection for the six BPs, benzophenone, 2,4-dihydroxybenzophenone, oxybenzone, 4- hydroxybenzophenone, octabenzone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, ranged from 0.011 to 0.15 μg/L. The intra-day and inter-day relative standard deviations varied from 0.7% to 16.6%. The method was applied to the analysis of lake and river water with good recoveries. It is cost effective, reliable, easy to operate, environment-friendly and promising in the real applications.

Ultrasound-assisted liquid–liquid microextraction based on an ionic liquid for preconcentration and determination of UV filters in environmental water samples

In the present study, a dispersive liquid–liquid microextraction with ionic liquids (ILs) as extraction solvents was developed for the preconcentration and determination of four ultraviolet (UV) filters from different environmental water samples. Ultrasound-assisted dispersion of the ILs in the water phase was employed. The UV filters were easily concentrated into the ionic liquid phase. This technique combined the process of extraction and concentration of the analytes into one step and avoided the use of more toxic halogenated solvents. Affecting factors including the type and volume of the ILs and disperser solvents, ultrasonic time, centrifugation time, ionic strength and pH of aqueous samples were optimized. The extracts were directly analyzed by high-performance liquid chromatography coupled with a diode array detector. Under the optimized conditions, the current method provided good repeatability (RSDs < 7.6%, n = 5) and high enrichment factors in the range of 492–834. The limits of detection (LOD) for the UV filters were in the range of 0.06–0.16 ng mL−1. The linearities were between 0.2 and 500 ng mL−1 for 2-hydroxy-4-methoxybenzophenone, 0.5 and 500 ng mL−1 for 2-ethylhexyl 4-(N,N-dimethylamino) benzoate, 0.4 and 500 ng mL−1 for 2-ethylhexyl-4-methoxycinnamate, and 0.5 and 500 ng mL−1 for 2-ethylhexyl salicylate, respectively. The current procedure was successfully applied to simultaneous analyses of four UV filters in environmental water samples. For all analyzed samples, the established method has allowed fast and reliable preconcentration and determination of these UV filters with simple sample pre-treatment requirements.

Determination of ultraviolet filters in environmental water samples by temperature-controlled ionic liquid dispersive liquid-phase microextraction

In the present study, a rapid, highly efficient and environmentally friendly sample preparation method named temperature-controlled ionic liquid dispersive liquid-phase microextraction (TC-IL-DLPME), followed by high performance liquid chromatography (HPLC) was developed for the extraction, preconcentration and determination of four benzophenone-type ultraviolet (UV) filters (viz. benzophenone (BP), 2-hydroxy-4-methoxybenzophenone (BP-3), ethylhexyl salicylate (EHS) and homosalate (HMS)) from water samples. An ultra-hydrophobic ionic liquid (IL) 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([HMIM][FAP]), was used as the extraction solvent in TC-IL-DLPME. Temperature served two functions here, the promotion of the dispersal of the IL to the aqueous sample solution to form infinitesimal IL drops and increase the interface between them and the target analytes (at high temperature), and the facilitation of mass transfer between the phases, and achievement of phase separation (at low temperature). Due to the ultra-hydrophobic feature and high density of the extraction solvent, complete phase separation could be effected by centrifugation. Moreover, no disperser solvent was required. Another prominent feature of the procedure was the combination of extraction and centrifugation in a single step, which not only greatly reduced the total analysis time for TC-IL-DLPME but also simplified the sample preparation procedure. Various parameters that affected the extraction efficiency (such as type and volume of extraction solvent, temperature, salt addition, extraction time and pH) were evaluated. Under optimal conditions, the proposed method provided good enrichment factors in the range of 240–350, and relative standard deviations (n=5) below 6.3%. The limits of detection were in the range of 0.2–5.0ng/mL, depending on the analytes. The linearities were between 1 and 500ng/mL for BP, 5 and 1000ng/mL for BP-3, 10 and 1000ng/mL for HMS and 5 and 1000ng/mL for EHS. Finally, the proposed method was successfully applied to the determination of UV filters in swimming pool and tap water samples and acceptable relative recoveries over the range of 88.0–116.0% were obtained.

Determination of ultraviolet filters in water samples by vortex-assisted dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry

For the first time, a simple solvent microextraction method termed vortex-assisted liquid–liquid microextraction (VADLLME) coupled with gas chromatography–mass spectrometry (GC–MS) has been developed and used for the analysis of six benzophenone ultraviolet (UV) filters (i.e. benzhydrol, 2,4-dihydroxybenzophenone, benzophenone, 2-hydroxy-4-methoxybenzophenone, ethylhexyl salicylate and homosalate) in water samples. The most favorable extraction variables in the VADLLME process were determined. In the extraction procedure, 40μL of tetrachloroethene as extraction solvent were directly injected into a 15-mL centrifuge tube containing 10mL of aqueous sample, adjusted to pH 4 for VADLLME. After VADLLME, the extract was evaporated under a gentle nitrogen gas stream and then reconstituted with N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA), thus allowing the target analytes to be converted into their trimethylsilyl derivatives to optimize the GC–MS analysis. No centrifugation and disperser solvent were required in this microextraction procedure. Significantly, short extraction time and high extraction efficiency were achieved. This method opens up a potentially new horizon for on-site dispersive liquid–liquid microextraction. Under the optimum conditions, the proposed method provided good enrichment factors up to 310, with relative standard deviations ranging from 6.1 to 12.9%. The limits of quantification were in the range of 20–100ng/L, depending on the analytes. The linearities were between 0.05 and 10μg/L and 0.1 and 10μg/L for different UV filters. Finally, the proposed method was successfully applied to the determination of UV filters from spiked genuine water samples and acceptable recoveries over the range of 71.0–120.0% were obtained.

Ionic liquid-based ultrasound-assisted dispersive liquid–liquid microextraction followed high-performance liquid chromatography for the determination of ultraviolet filters in environmental water samples

In the present study, a rapid, highly efficient and environmentally friendly sample preparation method named ionic liquid-based ultrasound-assisted dispersive liquid–liquid microextraction (IL-USA-DLLME), followed by high performance liquid chromatography (HPLC) has been developed for the extraction and preconcentration of four benzophenone-type ultraviolet (UV) filters (viz. benzophenone (BP), 2-hydroxy-4-methoxybenzophenone (BP-3), ethylhexyl salicylate (EHS) and homosalate (HMS)) from three different water matrices. The procedure was based on a ternary solvent system containing tiny droplets of ionic liquid (IL) in the sample solution formed by dissolving an appropriate amount of the IL extraction solvent 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([HMIM][FAP]) in a small amount of water-miscible dispersive solvent (methanol). An ultrasound-assisted process was applied to accelerate the formation of the fine cloudy solution, which markedly increased the extraction efficiency and reduced the equilibrium time. Various parameters that affected the extraction efficiency (such as type and volume of extraction and dispersive solvents, ionic strength, pH and extraction time) were evaluated. Under optimal conditions, the proposed method provided good enrichment factors in the range of 354–464, and good repeatability of the extractions (RSDs below 6.3%, n=5). The limits of detection were in the range of 0.2–5.0ngmL−1, depending on the analytes. The linearities were between 1 and 500ngmL−1 for BP, 5 and 500ngmL−1 for BP-3 and HMS and 10 and 500ngmL−1 for EHS. Finally, the proposed method was successfully applied to the determination of UV filters in river, swimming pool and tap water samples and acceptable relative recoveries over the range of 71.0–118.0% were obtained.