Study on the ability of indoor plants to absorb and purify benzene pollution.

The ability of indoor plants to purify benzene pollution is the basic basis for the selection of plants for ecological remediation of indoor benzene pollution. In this study, the purification rate and the purification amount per unit leaf area of 13 test plants at three benzene concentrations were determined by indoor fumigation experiments, and the benzene absorption and purification abilityability of indoor plants were comprehensively evaluated. The results showed that (1) there was a significant correlation between benzene concentration and purification rate and purification amount per unit leaf area. (2) At the three concentrations, Spathiphyllum floribundum showed the highest purification rate and Sansevieria trifasciata var. laurentii showed the highest purification per unit leaf area. (3) The combined results showed that Sansevieria trifasciata var. laurentii, Spathiphyllum floribundum and Aloe arborescens were the strongest absorbers and purifiers, while Podocarpus nagi and Anthurium andraeanum 'Pink champin' had the weakest absorption and purification capacity. The results of this study provide a theoretical basis and reference for the selection of plants with strong capacities to adsorb and purify benzene pollution in indoor air.

Cross-linked γ-cyclodextrin metal-organic framework-a new stationary phase for the separations of benzene series and polycyclic aromatic hydrocarbons.

The cross-linked γ-cyclodextrin metal-organic framework (CL-CD-MOF) was synthesized by crosslinking γ-cyclodextrin metal-organic framework (γ-CD-MOF) with diphenyl carbonate to separate benzene series and polycyclic aromatic hydrocarbons (PAHs). The separation ability of the CL-CD-MOF packed column was assessed in both reverse-phase (RP-) and normal-phase (NP-) modes. The retention mechanisms of these compounds were discussed and confirmed by combining molecular simulations in detail. It was found that baseline separation could be obtained in RP-HPLC mode and it was superior to commercial C18 column in separating xylene isomers. The interaction between CL-CD-MOF and analytes, such as dipole-dipole interaction, π-electron transfer interaction, hydrophobic interaction, and van der Waals force, may dominate the chromatographic separation, and CL-CD-MOF column had a certain shape recognition ability. In addition, the composition of the mobile phase also had a crucial effect. Moreover, the column demonstrated satisfactory stability and repeatability (the relative standard deviations of retention time, peak height, peak area, and half peak width for six replicate separations of the tested analytes were within the ranges 0.17-1.1%, 0.96-1.9%, 0.23-1.7%, and 0.32-1.9%, respectively) and there was no significant change in the separation efficiency for at least 3 years of use. Thermodynamic characteristics indicated that the process of separations on the CL-CD-MOF column was both negative enthalpy change (ΔH) and entropy change (ΔS) controlled. The excellent performance made CL-CD-MOF a promising HPLC stationary phase material for separation and determination of benzene series and PAHs.

Analytical Separation of Carcinogenic and Genotoxic Alkenylbenzenes in Foods and Related Products (2010-2020).

Alkenylbenzenes are potentially toxic (genotoxic and carcinogenic) compounds present in plants such as basil, tarragon, anise star and lemongrass. These plants are found in various edible consumer products, e.g., popularly used to flavour food. Thus, there are concerns about the possible health consequences upon increased exposure to alkenylbenzenes especially due to food intake. It is therefore important to constantly monitor the amounts of alkenylbenzenes in our food chain. A major challenge in the determination of alkenylbenzenes in foods is the complexity of the sample matrices and the typically low amounts of alkenylbenzenes present. This review will therefore discuss the background and importance of analytical separation methods from papers reported from 2010 to 2020 for the determination of alkenylbenzenes in foods and related products. The separation techniques commonly used were gas and liquid chromatography (LC). The sample preparation techniques used in conjunction with the separation techniques were various variants of extraction (solvent extraction, liquid-liquid extraction, liquid-phase microextraction, solid phase extraction) and distillation (steam and hydro-). Detection was by flame ionisation and mass spectrometry (MS) in gas chromatography (GC) while in liquid chromatography was mainly by spectrophotometry.

A polythiophene/UiO-66 composite coating for extraction of volatile organic compounds migrated from ion-exchange resins prior to their determination by gas chromatography.

A Poly (3,4-ethylenedioxothiophene) (PEDOT)/UiO-66 composite was electrodeposited on an etched stainless-steel wire as head-space solid-phase microextraction (HS-SPME) coating. A robust, well controlled thickness, and uniform coating of metal organic framework composites can be realized by the electrodeposited strategy. The incorporated UiO-66 not only enhanced the uniformity and stability of the composite coating, but also effectively decreased the stacking phenomenon of PEDOT and improved its extraction efficiency, which was over 100 times higher than that of the PEDOT coating without UiO-66. The composite coating was used to enrich seven types of volatile organic compounds (VOCs) in ion-exchange resins, including methyl cyclohexane, benzene, toluene, ortho-xylene, styrene, para-xylene and divinyl-benzene. The results of adsorption isotherm analysis showed that π stacking effect played dominant role between the composite coating and VOCs in the extraction process. The composite coating was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared and thermogravimetric analysis, respectively. A determination method for seven kinds of VOCs was established by HS-SPME coupled with gas chromatography-flame ionization detection (GC-FID). Under the optimal experimental conditions, the detection linear range (LRs) was 0.09-100 ng mL-1, and the detection limit (LODs) was 0.03-0.06 ng mL-1 (S/N = 3). The method was applied for the migration detection of VOCs in four types of ion-exchange resin, which showed satisfactory recovery (84.5-117.2%).

Combination of highly efficient microflora to degrade paint spray exhaust gas.

Spray paint exhaust gas contains recalcitrant volatile organic compounds (VOCs), such as benzene, toluene and xylene (BTX). Treating BTX with a biofilter often achieves unsatisfactory results because the biofilter lacks efficient microbial community. In this work, three strains for BTX degradation were isolated and identified as Pseudomonas putida, Bacillus cereus and Bacillus subtilis by using 16S rRNA sequencing technology. A consortium of highly efficient microbial community was then constructed on a stable biofilm to treat BTX in a biofilter. A relatively suitable ratio of P. putida, B. cereus and B. subtilis was obtained. An efficiency of over 90% was achieved in the biofilter with VOC concentration of 1000 mg/m3 through inoculation with the microbial community after only 10 days of operation. Thus, fast start-up of the biofilter was realised. Analysis of intermediate products by gas chromatography-mass spectrometry indicated that BTX was degraded into short-chain aldehydes or acids via ring opening reactions.

Vegetal fiber paper matrix impregnated with silica gel for benzene removal.

Removing benzene from indoor space plays an important role in indoor air purification. A novel filter with vegetal fiber paper (VFP) as matrix hosting silica gel is proposed in this paper for benzene removal. In order to investigate the feasibility and performance of this idea, firstly, three pieces of VFP samples impregnated with different amounts of silica gel are fabricated and their benzene adsorption quantities are tested. The results show that three times is recommended as the optimal number for impregnating. The VFP sample impregnated with silica gel after the third impregnating exhibits commendable coating stability and good benzene adsorption performance. Additionally, at low relative pressure (Pb /Ps  ≤ 0.05), the experimental data of benzene adsorption isotherms fit well with the Langmuir model with R2 greater than 0.97. Then, two actual filters made of VFP impregnated with silica gel after the third impregnating were fabricated. It is found that the pressure drop of the actual filter is only 1200 Pa/m when the air velocity is 2 m/s. Besides, the one-pass efficiency of the filter can reach to 19.44%. It is expected that the silica gel coated on the filter can be modified to improve the purification performance of the filter.

Sericin-coated polyester based air-filter for removal of particulate matter and volatile organic compounds (BTEX) from indoor air.

Particulate matter and volatile organic compounds have emerged as a prime environmental concern with increasing air pollution in metropolitan cities leading to lung and heart-related issues. This paper describes a facile and novel method for fabrication of polyester based air filter via surface coating with Sericin for imparting effective removal of particulate matter and volatile organic compounds. A simple dip-coating method followed by thermal fixation has been adopted to coat Sericin on the polyester fiber. The developed changes in surface functionality and morphology of the polyester fiber were confirmed by Attenuated total reflection Fourier-transform infrared spectroscopy and Field emission scanning electron microscopy analysis. The fabricated air filter was tested for removal of particulate matter (generated burning incense stick) and volatile organic compounds (generated vaporizing gasoline), in an indoor chamber. The Sericin coated filter was able to remove the PM2.5 and PM 10 (from 1000 µg/m3 level to 5 µg/m3 in a 6.28 m3 chamber) within 27 and 23 min of operation, respectively. The fabricated filter very effectively removed particulate matter for 2160 cycles with intermittent washing. The Sericin-coated air filter also proved very effective for removal of volatile organic compounds (Benzene, Toluene, Ethylbenzene and Xylene) from an indoor chamber at a varying initial concentration of 100-1000 µg/m3. The adsorption behavior was described by Langmuir-Freundlich (sips) isotherm and pseudo-first order kinetics with minimal error. The maximum adsorption capacity (mg/g) obtained with Sips Isotherm fitting followed the order Xylene (6.97)>Ethyl Benzene (5.68)> Toluene (5.35) >Benzene (4.78).

Does plant species selection in functional active green walls influence VOC phytoremediation efficiency?

Volatile organic compounds (VOCs) are of public concern due to their adverse health effects. Botanical air filtration is a promising technology for reducing indoor air contaminants, but the underlying mechanisms are not fully understood. This study assessed active botanical biofilters for their single-pass removal efficiency (SPRE) for benzene, ethyl acetate and ambient total volatile organic compounds (TVOCs), at concentrations of in situ relevance. Biofilters containing four plant species (Chlorophytum orchidastrum, Nematanthus glabra, Nephrolepis cordifolia 'duffii' and Schefflera arboricola) were compared to discern whether plant selection influenced VOC SPRE. Amongst all tested plant species, benzene SPREs were between 45.54 and 59.50%, with N. glabra the most efficient. The botanical biofilters removed 32.36-91.19% of ethyl acetate, with C. orchidastrum and S. arboricola recording significantly higher ethyl acetate SPREs than N. glabra and N. cordifolia. These findings thus indicate that plant type influences botanical biofilter VOC removal. It is proposed that ethyl acetate SPREs were dependent on hydrophilic adsorbent sites, with increasing root surface area, root diameter and root mass all associated with increasing ethyl acetate SPRE. The high benzene SPRE of N. glabra is likely due to the high wax content in its leaf cuticles. The SPREs for the relatively low levels of ambient TVOCs were consistent amongst plant species, providing no evidence to suggest that in situ TVOC removal is influenced by plant choice. Nonetheless, as inter-species differences do exist for some VOCs, botanical biofilters using a mixture of plants is proposed.

Municipal solid waste-derived biochar for the removal of benzene from landfill leachate.

The potential of biochar, produced from fibrous organic fractions of municipal solid waste (MSW), for remediation of benzene, one of the frequently found toxic volatile organic compounds in landfill leachate, was investigated in this study based on various environmental conditions such as varying pH, benzene concentration, temperature and time. At the same time, landfill leachate quality parameters were assessed at two different dump sites in Sri Lanka: Gohagoda and Kurunegala. MSW biochar (MSW-BC) was produced by slow temperature pyrolysis at 450 °C, and the physiochemical characteristics of the MSW-BC were characterized. All the leachate samples from the MSW dump sites exceeded the World Health Organization permissible level for benzene (5 µg/L) in water. Removal of benzene was increased with increasing pH, with the highest removal observed at ~pH 9. The maximum adsorption capacity of 576 µg/g was reported at room temperature (~25 °C). Both Freundlich and Langmuir models fitted best with the equilibrium isotherm data, suggesting the involvement of both physisorption and chemisorption mechanisms. Thermodynamic data indicated the feasibility of benzene adsorption and its high favorability at higher temperatures. The values of [Formula: see text] suggested physical interactions between sorbate and sorbent, whereas kinetic data implied a significant contribution of chemisorption. Results obtained from FTIR provided clear evidence of the involvement of functional groups in biochar for benzene adsorption. This study suggests that MSW biochar could be a possible remedy for benzene removal from landfill leachate and at the same time MSW can be a potential source to produce biochar which acts as a prospective material to remediate its pollutants while reducing the volume of waste.

[In silico Search for Tubulin Polymerization Inhibitors].

Cytostatic colchicine is widely used in the treatment of Familial Mediterranean fever, but it has several side effects. For finding new, more effective drugs with higher affinity and diminishside effects we carried out virtual screening of potential inhibitors of the main target of colchicine, the polymerization of tubulin by evaluating affinity 25745 compounds, structurally related to the colchicine. We have identified 11 commercially available compounds with higher affinity to tubulin. Compounds with highest binding scores include trimethoxybenzene and its derivatives; these compounds bind to the same site in similar orientation. Information provided can form the basis for design of new cytostatics.

Efficient removal of benzene in air at atmospheric pressure using a side-on type 172 nm Xe2 excimer lamp.

The photochemical removal of benzene was studied in air at atmospheric pressure using a side-on type 172 nm Xe2 excimer lamp with a wide irradiation area. After 1.5 min photoirradiation, C6H6 (1000 ppm) in air was completely converted to HCOOH, CO, and CO2 at a total flow rate of 1000 mL/min. The initial decomposition rate of C6H6 was determined to be 1.18 min-1. By using a flow system, C6H6 (200 ppm) was completely removed at a total flow rate of 250 mL/min. The conversion of C6H6 and the energy efficiency in the removal of C6H6 changed in the 31-100% and 0.48-1.2 g/kWh range, respectively, depending on the flow rate, the O2 concentration, and the chamber volume. On the basis of kinetic model simulation, dominant reaction pathways were discussed. Results show that the O(3P) + C6H6 reaction plays a significant role in the initial stage of the C6H6 decomposition. Important experimental parameters required for further improvement of the C6H6 removal apparatus using a 172 excimer lamp were discussed based on model calculations.

Lab-In-Syringe automation of stirring-assisted room-temperature headspace extraction coupled online to gas chromatography with flame ionization detection for determination of benzene, toluene, ethylbenzene, and xylenes in surface waters.

Online coupling of Lab-In-Syringe automated headspace extraction to gas chromatography has been studied. The developed methodology was successfully applied to surface water analysis using benzene, toluene, ethylbenzene, and xylenes as model analytes. The extraction system consisted of an automatic syringe pump with a 5 mL syringe into which all solutions and air for headspace formation were aspirated. The syringe piston featured a longitudinal channel, which allowed connecting the syringe void directly to a gas chromatograph with flame ionization detector via a transfer capillary. Gas injection was achieved via opening a computer-controlled pinch valve and compressing the headspace, upon which separation was initialized. Extractions were performed at room temperature; yet sensitivity comparable to previous work was obtained by high headspace to sample ratio VHS/VSample of 1.6:1 and injection of about 77% of the headspace. Assistance by in-syringe magnetic stirring yielded an about threefold increase in extraction efficiency. Interferences were compensated by using chlorobenzene as an internal standard. Syringe cleaning and extraction lasting over 10 min was carried out in parallel to the chromatographic run enabling a time of analysis of <19 min. Excellent peak area repeatabilities with RSD of <4% when omitting and <2% RSD when using internal standard corrections on 100 µg L-1 level were achieved. An average recovery of 97.7% and limit of detection of 1-2 µg L-1 were obtained in analyses of surface water.

Graphene-doped electrochemical copolymer coating of 2,2-bithiophene and 3-methylthiophene for the highly effective solid-phase microextraction of volatile benzene homologues.

We report the electrochemical fabrication of a poly(2,2-bithiophene-co-3-methylthiophene)-graphene composite coating and its application in the headspace solid-phase microextraction and gas chromatography determination of benzenes (i.e., bromobenzene, 4-bromotoluene, 2-nitrotoluene, 3-nitrotoluene and 1,2,4-trichlorobenzene). The coating was uniform and showed cauliflower-like microstructure. It had high thermal stability (up to 375°C) and could be used for at least 180 times of solid-phase microextraction without a decrease in extraction performance. Furthermore, it presented high extraction capacity for the benzenes due to the hydrophobic effect and π-π interaction between the analytes and the coating. Under optimized extraction conditions, good linearity (correlation coefficients higher than 0.9946), wide linear range (0.01-50 µg/L), and low limits of detection (5.25-12.5 ng/L) were achieved for these analytes. The relative standard deviation was lower than 5.7% for five successive measurements with one fiber, and the relative standard deviation for fiber-to-fiber was 4.9-6.8% (n = 5). The solid-phase microextraction and gas chromatography method was successfully applied for the determination of three real samples, and the recoveries for standards added were 89.6-106% for nail polish, 85.8-110% for hair dye, and 90-106.2% for correction fluid, respectively.

Micro-solid phase extraction of benzene, toluene, ethylbenzene and xylenes from aqueous solutions using water-insoluble ß-cyclodextrin polymer as sorbent.

Water-insoluble ß-cyclodextrin polymer was synthesized by chemical cross-linking using epichlorohydrin (EPI) as a cross-linker agent. The produced water-insoluble polymer was used as a sorbent for the micro-solid phase extraction (µ-SPE) of benzene, toluene, ethylbenzene and xylenes (BTEX) from water samples. The µ-SPE device consisted of a sealed tea bag envelope containing 15mg of sorbent. For the evaluation of the extraction efficiency, parameters such as extraction and desorption time, desorption solvent and salt concentration were investigated. At an extraction time of 30min in the course of the extraction process, analytes were extracted from a 10mL aqueous sample solution. The analytes were desorbed by ultrasonication in 200µL of acetonitrile for 20min. Analysis of the analytes was done by a gas chromatography-flame ionization detector (GC-FID) system. The enrichment factor (EF) was found to be in the range 23.0-45.4 (EFmax=50.0). The method provided linearity ranges of between 0.5 and 500.0ng/mL (depending on the analytes), with good coefficients of determination (r2) ranging between 0.997 and 0.999 under optimized conditions. Detection limits for BTEX were in the range of between 0.15 and 0.60ng/mL, while corresponding recoveries were in the range of 46.0-90.0%. The relative standard deviation of the method for the analytes at 100.0ng/mL concentration level ranged from 5.5 to 11.2% (n=5). The proposed method was concluded to be a cost effective and environmentally-friendly extraction technique with ease of operation and minimal usage of organic solvent.

Breathable Vapor Toxicant Barriers Based on Multilayer Graphene Oxide.

There is tremendous interest in graphene-based membranes as protective molecular barriers or molecular sieves for separation technologies. Graphene oxide (GO) films in the dry state are known to be effective barriers for molecular transport and to expand in the presence of moisture to create enlarged intersheet gallery spaces that allow rapid water permeation. Here we explore an application for GO membranes as water-breathable barrier layers for personal protective equipment, which are designed to allow outward perspiration while protecting the wearer from chemical toxicants or biochemical agents in the local environment. A device was developed to measure permeation rates of small-molecular toxicants in the presence of counter-current water flow simulating active perspiration. The technique was applied to trichloroethylene (TCE) and benzene, which are important environmental toxicants, and ethanol as a limiting case to model very small, highly water-soluble organic molecules. Submicron GO membranes are shown to be effective TCE barriers, both in the presence and absence of simulated perspiration flux, and to outperform current barrier technologies. A molecular transport model is developed, which suggests the limited toxicant back-permeation observed occurs not by diffusion against the convective perspiration flow in hydrophobic channels, but rather through oxidized domains where hydrogen-bonding produces a near-stagnant water phase. Benzene and ethanol permeation fluxes are higher than those for TCE, likely reflecting the effects of higher water solubility and smaller minimum molecular dimension. Overall, GO films have high water breathability relative to competing technologies and are known to exclude most classes of target toxicants, including particles, bacteria, viruses, and macromolecules. The present results show good barrier performance for some very small-molecule species, but not others, with permeation being favored by high water solubility and small minimum molecular dimension.

Potential application of an Aspergillus strain in a pilot biofilter for benzene biodegradation.

A biofilter with fungus was developed for efficient degradation of benzene, which can overcome the potential risk of leakage commonly found in such services. Results indicated that the optimum parameter values were temperature 40 °C, pH 6, and 500 mg L-1 of the initial benzene concentration. Besides, the empty bed residence time and inlet load range of biofilter were set to 20 s and 21.23-169.84 g m-3 h-1 respectively. Under these conditions, this biofilter can obtain the maximum removal efficiency of more than 90%, the eliminating capacity could be up to 151.67 g m-3 h-1. Furthermore, scanning electron microscopy was used to investigate three filler materials for packing fungus biofilm. This is the first study introducing an Aspergillus strain for benzene removal and these results highlight that the development of this biofilter has the potential scaling-up application as gas-processing of industrial wastes.

Biodegradation of BTEX Aromatics by a Haloduric Microbial Consortium Enriched from a Sediment of Bohai Sea, China.

This study focused on a haloduric BTEX-degrading microbial consortium EC20 enriched from Bohai Sea sediment. EC20 degraded 87% of BTEX at 435 mg L-1 initial concentration (benzene, toluene, ethylbenzene, and xylenes in equal proportions) in the presence of 3.4% NaCl. 16S rRNA gene-based PCR-DGGE profiles revealed that the dominant bacteria in EC20 were Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes at the phylum level, and Pseudomonas, Mesorhizobium, Achromobacter, Stenotrophomonas, and Halomonas at the genus level. PCR detection of genes coding the key enzymes which participated in BTEX degradation pathways showed that the enriched consortium EC20 contained TOL pathway and TOD pathway to initiate biodegradation of BTEX.

Extraction of toxic compounds from saliva by magnetic-stirring-assisted micro-solid-phase extraction step followed by headspace-gas chromatography-ion mobility spectrometry.

A new sample extraction procedure based on micro-solid-phase extraction (µSPE) using a mixture of sorbents of different polarities (polymeric reversed-phase sorbent HLB, silica-based sorbent C18, and multiwalled carbon nanotubes) was applied to extract benzene, toluene, butyraldehyde, benzaldehyde, and tolualdehyde present in saliva to avoid interference from moisture and matrix components and enhance sensitivity and selectivity of the ion mobility spectrometry (IMS) methodology proposed. The extraction of target analytes from saliva samples by using µSPE were followed by the desorption step carried out in the headspace vials placed in the autosampler of the IMS device. Then, 200 µL of headspace was injected into the GC column coupled to the IMS for its analysis. The method was fully validated in terms of sensitivity, precision, and recovery. The LODs and LOQs obtained, when analytes were dissolved in saliva samples to consider the matrix effect, were within the range of 0.38-0.49 and 1.26-1.66 µg mL(-1), respectively. The relative standard deviations were <3.5 % for retention time and drift time values, which indicate that the method proposed can be applied to determine toxic compounds in saliva samples. Graphical abstract Summary of steps followed in the experimental set up of this work.

A Novel Optimization Technique to Improve Gas Recognition by Electronic Noses Based on the Enhanced Krill Herd Algorithm.

An electronic nose (E-nose) is an intelligent system that we will use in this paper to distinguish three indoor pollutant gases (benzene (C6H6), toluene (C7H8), formaldehyde (CH2O)) and carbon monoxide (CO). The algorithm is a key part of an E-nose system mainly composed of data processing and pattern recognition. In this paper, we employ support vector machine (SVM) to distinguish indoor pollutant gases and two of its parameters need to be optimized, so in order to improve the performance of SVM, in other words, to get a higher gas recognition rate, an effective enhanced krill herd algorithm (EKH) based on a novel decision weighting factor computing method is proposed to optimize the two SVM parameters. Krill herd (KH) is an effective method in practice, however, on occasion, it cannot avoid the influence of some local best solutions so it cannot always find the global optimization value. In addition its search ability relies fully on randomness, so it cannot always converge rapidly. To address these issues we propose an enhanced KH (EKH) to improve the global searching and convergence speed performance of KH. To obtain a more accurate model of the krill behavior, an updated crossover operator is added to the approach. We can guarantee the krill group are diversiform at the early stage of iterations, and have a good performance in local searching ability at the later stage of iterations. The recognition results of EKH are compared with those of other optimization algorithms (including KH, chaotic KH (CKH), quantum-behaved particle swarm optimization (QPSO), particle swarm optimization (PSO) and genetic algorithm (GA)), and we can find that EKH is better than the other considered methods. The research results verify that EKH not only significantly improves the performance of our E-nose system, but also provides a good beginning and theoretical basis for further study about other improved krill algorithms' applications in all E-nose application areas.

Zeolite/iron oxide composite as sorbent for magnetic solid-phase extraction of benzene, toluene, ethylbenzene and xylenes from water samples prior to gas chromatography⬜mass spectrometry.

This study reports a new composite based on ZSM-5 zeolite decorated with iron oxide magnetic nanoparticles as a valuable sorbent for magnetic solid-phase extraction (MSPE). A proposal is made to determine benzene, toluene, ethylbenzene and xylenes (BTEX) as model analytes in water samples using gas chromatography-mass spectrometry. A two-step multivariate optimization strategy, using Plackett⬜Burman and circumscribed central composite designs, was employed to optimize experimental parameters affecting MSPE. The method was evaluated under optimized extraction conditions (i.e., amount of sorbent, 138mg; extraction time, 11min; sample pH, pH of water (i.e., 5.5⬜6.5); eluent solvent volume, 0.5mL; and elution time, 5min), obtaining a linear response from 1 to 100µgL(↙1) for benzene; from 10 to 100µgL(↙1) for toluene, ethylbenzene and o-xylene; and from 10 to 75µgL(↙1) for m,p-xylene. The repeatability of the proposed method was evaluated at a 40µgL(↙1) spiking level and coefficients of variation ranged between 8 and 11% (n=5). Limits of detection were found to be 0.3µgL(↙1) for benzene and 3µgL(↙1) for the other analytes. These values satisfy the current normative of the Environmental Protection Agency and European Union for BTEX content in waters for human consumption. Finally, drinking water, wastewater and river water were selected as real water samples to assess the applicability of the method. Relative recoveries varied between 85% and 114% showing negligible matrix effects.