Extraction Of Persistent Organic Pollutants Research Articles

Greener production of a starch-based nanohybrid material (core-shell) for the simultaneous extraction of persistent organic pollutants in shrimp samples

Here, a novel nanohybrid material (Ag@CD@ANS) based on oat starch was produced, characterized, and applied to extract persistent organic pollutants in a shrimp sample. By the characterization experiments, Ag@CD@ANS was successfully synthesized. The functionalization of the material by 1,2-naphthoquinone-4-sulphonic acid (ANS) was confirmed using the infrared technique and CHN elemental analysis. The isotherm study showed that the material has a high adsorption capacity for the pesticides of interest (flutriafol, atrazine, heptachlor, DDT and bifenthrin) allowing their extraction from shrimp samples. The optimal condition for extraction was obtained using multivariate analysis. The nature of the elution solvent (hexane, methanol, acetonitrile) and the mass ratio between sample:adsorbent (1:1; 1:5 and 1:10) were the evaluated factors for extraction using Ag@CD@ANS and commercial adsorbents (neutral alumina, octadecyl, silica gel). From the multivariate analysis, it was observed that the optimal condition for pesticide extraction using Ag@CD@ANS was reached, using a 1:5 ratio (sample:adsorbent) and acetonitrile (10 mL) as elution solvent. For the commercial adsorbents, the optimal condition for pesticide extraction was reached, using a 1:3 ratio (sample:adsorbent), acetonitrile (10 mL) and neutral alumina as commercial adsorbent. Ag@CD@ANS efficiency was compared with an optimal commercial adsorbent (neutral alumina). No significant difference (p < 0.05) between neutral alumina and Ag@CD@ANS was observed. Recoveries ranging from 75 to 105 % with coefficients of variation ≤ 15 % (n = 3) were obtained using neutral alumina while using Ag@CD@ANS, recoveries ranging from 73 to 102 %, with coefficient of variation ≤ 13 % (n = 3) were obtained for the target pesticides. Limits of detection ranging from 0.5 to 1.0 µg Kg−1 and limits of quantification ranging from 1.6 to 3.3 µg Kg−1 were reached. The results demonstrated that Ag@CD@ANS can alternatively be used as a support for the extraction of persistent organic pollutants, having the advantage of being reusable for up to three cycles.

Screening of ionic liquids and deep eutectic solvents for the extraction of persistent organic pollutants from edible oils and fat

Presence of persistent organic pollutants (POPs) like polychlorinated-p-dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in edible oils poses risk to human health. Ionic liquids (ILs) and deep eutectic solvents (DESs) are novel combinatorial solvents with a proven record of extraction of such persistent organic pollutants (POPs). However, the large possibility of such combinatorial solvents necessitates an a-priori screening strategy to select the best possible ILs and DESs. Therefore, a Conductor like Screening Model Segment Activity Coefficient (COSMO-SAC) based framework has been employed to extract 27 POPs (6 PCDDs, 9 PCDFs, 12 PCBs) from five types of edible oil and animal fat by ILs and DESs. The screening will create such a list and based on that experimentation can be performed. There are five different types of oils and fats such as sunflower oil, soya lecithin, rapeseed oil, fish oil, and milk fat that are selected as potential sources of PCDD/Fs and PCBs. A combination of 58 cations and 39 anions which will yield 2262 types of IL and 217 types of DESs with the proportional combination of 24 HBAs and 62 HBDs are considered. Infinite dilution activity coefficient (IDAC) and solubility are calculated based on COSMO-SAC modelling and a set of ILs and DESs are screened as a potential extractant for POPs. The study aims to select the most suitable green solvents to extract these POPs from edible oils to render them safe for consumption.

A solid phase microextraction Arrow with zirconium metal–organic framework/molybdenum disulfide coating coupled with gas chromatography–mass spectrometer for the determination of polycyclic aromatic hydrocarbons in fish samples

Solid phase microextraction (SPME) Arrows with enlarged sorption phases and Arrow-shaped tips are good alternatives to classic SPME fibers. Developing SPME Arrows with functionalized coatings has become a growing area of SPME research. In this study, a zirconium metal organic framework/molybdenum disulfide (UiO-66/MoS2) composite coating modified SPME Arrow was developed and coupled with gas chromatography-mass spectrometry for the headspace extraction and detection of 16 polycyclic aromatic hydrocarbons (PAHs). The coating preparation can be easily manipulated by the assembly strategy using silicone gels to adhere UiO-66/MoS2 powder onto the surface of the Arrows. The prepared UiO-66/MoS2 coated SPME Arrows exhibited clearly enhanced adsorption capacity (2.1–4.5 folds) and an improved degree of affinity to PAHs species when compared to commercial PDMS/CARS/DVB SPME Arrows or fibers. The improved mechanism may be due to the high specific area, hierarchical micropores and mesopores, and the largely increased and immobilized amount of UiO-66/MoS2 coating on the stainless-steel Arrow. Under optimized conditions, the SPME Arrow-based assay was successfully applied to determine PAH levels in fish samples with satisfactory recoveries of 80.2–101% and relative standard deviations (RSDs) of less than 6%. The detection limits of PAHs were between 0.11–1.40 ng kg−1. The coating showed satisfied reproducibility and repeatability (RSD <8.6%) with only 10 mL of 10% (v/v) acetone in water used as the extraction phase in an effort to be environmentally friendly. All of the results showed that the method is simple, sensitive, and robust. SPME Arrows with UiO-66/MoS2 coatings can provide new opportunities for the efficient extraction of persistent organic pollutants in food safety applications.

Concomitant evaluation of atmospheric levels of polychlorinated biphenyls, organochlorine pesticides, and polycyclic aromatic hydrocarbons in Strasbourg (France) using pine needle passive samplers.

In this study, pine needles were used as cost-effective and reliable passive bio-monitors to concomitantly evaluate atmospheric concentrations of three classes of persistent organic pollutants, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs). The extraction of persistent organic pollutants (POPs) from needle samples was performed. Eleven PCBs, 11 OCPs, and 15 PAHs were detected and followed through time in needle samples from three sites in the Strasbourg region. The urban and rural sites were more exposed to PCBs than the suburban site. The highest concentration of PCBs was found at the urban site, but the largest number of congeners (10) was detected at the rural site. PCB 189 and 156 were the predominant congeners in the rural site and PCB 70 in the urban site. For OCPs, the rural site displayed the highest concentrations (up to 22.9 ng g(-1)) and number of compounds investigated (9). The high concentration of γ- and β-hexachlorocyclohexane (HCH) at that time in the urban site was the reason for this result. γ- and β-HCH were the two predominant compounds in all samples. The suburban and urban sites were the most exposed with PAHs with pyrene, phenanthrene, and acenaphthene being the three predominant compounds in these sites. No specific trend in terms of time was apparent for PCBs and OCPs. However, higher concentrations were detected for some compounds in the first sampling, especially for PAHs, and this is attributed to variations in meteorological conditions (e.g., temperature, wind, rain) and variable inputs from both identified and unidentified sources.

Supercritical fluid extraction of persistent organic pollutants from natural and artificial soils and comparison with bioaccumulation in earthworms

Selective supercritical fluid extraction (SSFE) was used as a measurement of compound chemical accessibility and as a predictor of compound bioavailability from three natural soils and artificial analogues prepared to have comparable total organic carbon content. Soils spiked with phenanthrene, pyrene, PCB 153, lindane, and p,p′-DDT were aged for 0, 14, 28, or 56 days and then selectively extracted by supercritical fluid extraction. Compounds exhibited decreasing extractability with increasing pollutant–soil contact time and increasing total organic carbon content in tested soils. However, the different extractability of compounds from artificial and natural pairs having comparable TOC indicates the limitations of using TOC as an extrapolation basis between various soils. The comparison of extractability with bioaccumulation by earthworms (Eisenia fetida) previously published by Vlčková and Hofman (2012) showed that only for PAHs it was possible to predict their bioaccumulation by means of selective SFE.

New home-made assembly for hollow-fibre membrane extraction of persistent organic pollutants from real world samples

Nowadays, hollow fibre membrane extraction techniques are widely used but they are usually applied to water or very simple matrices such as water. In this paper, we propose a new assembly that allows the extraction of forty persistent organic pollutants in real world samples, namely orange juice, porcine plasma and tomatoes. The limits of detection obtained are very low even in the analysis of real samples (9–182 ng L −1). The relative standard deviations vary from 1 to 18% and the averaged recoveries in the spike experiments are very high (65–120%) in the different types of samples studied. The new assembly allows a very good precision overcoming in one of the most important shortcomings of membrane extraction techniques. A central composite design has been performed to get optimal extraction conditions for the analytes and also the combined response of all the analytes has been obtained to attain the simultaneous optimum.

Simplification and validation of a large volume polyurethane foam sampler for the analysis of persistent hydrophobic compounds in drinking water

The use of a large volume polyurethane foam (PUF) sampler was validated for rapid extraction of persistent organic pollutants (POPs), such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), in raw water and treated water from drinking water plants. To validate the recovery of target compounds in the sampling process, a (37)Cl-labeled standard was spiked into the 1st PUF plug prior to filtration. An accelerated solvent extraction method, as a pressurized liquid extractor (PLE), was optimized to extract the PUF plug. For sample preparation, tandem column chromatography (TCC) clean-up was used for rapid analysis. The recoveries of labeled compounds in the analytical method were 80-110% (n = 9). The optimized PUF-PLE-TCC method was applied in the analysis of raw water and treated potable water from seven drinking water plants in South Korea. The sample volume used was between 18 and 102 L for raw water at a flow rate of 0.4-2 L min(-1), 95 and 107 L for treated water at a flow rate of 1.5-2.2 L min(-1). Limit of quantitation (LOQ) was a function of sample volume and it decreased with increasing sample volume. The LOQ of PCDD/Fs in raw waters analyzed by this method was 3-11 times lower than that described using large-size disk-type solid phase extraction (SPE) method. The LOQ of PCDD/F congeners in raw water and treated water were 0.022-3.9 ng L(-1) and 0.018-0.74 ng L(-1), respectively. Octachlorinated dibenzo-p-dioxin (OCDD) was found in some raw water samples, while their concentrations were well below the tentative criterion set by the Japanese Environmental Ministry for drinking water. OCDD was below the LOQ in the treated drinking water.

Ultrasonic Solvent Extraction of Persistent Organic Pollutants from Airborne Particles

AbstractUltrasonic solvent extraction of persistent organic pollutants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) from airborne particles is reported. The extraction was optimized as functions of type and amount of solvent, sonication time, and number of extraction steps. Determination of PAHs and PCBs carried out by GC/MSD, while OCPs were determined using GC/μ‐ECD. The optimum extraction procedure was determined as three times consecutive extraction using a 25 mL mixture of n‐hexane:petroleum ether (1/1, v/v) for 15 min of sonication. Recoveries were obtained between 91 ± 2 and 96 ± 1% with Relative Standard Deviation (RSD) ⪇ ± 4% for PCBs, for PAHs recoveries (except for naphthalene, &lt; 31%) were between 66 ± 6 and 90 ± 4% with RSD ⪇ ± 8% while OCPs compounds recoveries were between 67 ± 5 and 120 ± 7% with RSD ⪇ ± 7%. When comparing the Soxhlet extraction method with optimized ultrasonic solvent extraction method, extraction time and solvent volume were reduced considerably with the ultrasonic solvent extraction method without reducing extraction efficiency. In addition, a simultaneous analysis of PCBs, PAHs, and OCPs in one sampling by the optimized method is quite advantageous in terms of analysis time and cost.

New strategies for extraction and clean-up of persistent organic pollutants from food and feed samples using selective pressurized liquid extraction

Pressurized liquid extraction (PLE) has gained wide acceptance for the extraction of persistent organic pollutants (POPs) from various environmental and biological matrices. This extraction technique was developed to shorten the extraction step, since this is one of the most time-consuming steps in many analytical procedures. When POPs enter the food chain, as in a number of recent food crises, thousands of samples have to be analyzed in a short time to protect humans from severe POP exposure. In such cases, PLE provides a good alternative to conventional extraction techniques. This article gives an overview of a number of studies of the extraction of POPs from food and feed, using PLE. Of special interest are applications dealing with selective extraction procedures, where integrated clean-up strategies are utilized to combine extraction and clean-up or fractionation to simplify further the entire sample-preparation chain.

Measuring bioavailability of polychlorinated biphenyls in soil to earthworms using selective supercritical fluid extraction

If the release mechanisms during selective chemical extraction of persistent organic pollutants (POP) mimic release mechanisms in natural systems during biological uptake, then a selective non-exhaustive extraction could give a quantitative measure of the bioavailable POP fraction. Supercritical fluid extraction (SFE) is suggested as a possible technique to estimate the amount of bioavailable polychlorinated biphenyls (PCBs) at contaminated sites and hence serve as a new tool in risk assessment. The uptake of PCBs by earthworm ( Eisenia foetida) was investigated. PCB contaminated soil was pre-extracted with selective non-exhaustive SFE (50 °C, 350 bar, 1 h), which removed on average 70% of the individual PCBs. Earthworms were placed in this pre-extracted soil, as well as in untreated soil. After 10 days, the PCB uptake by earthworms in the two systems was compared. The bioaccumulation factor (BAF) was 83% lower in the pre-extracted system than in the untreated system, demonstrating that SFE extracts primarily bioavailable contaminants. From the data, the bioavailable fraction could also be calculated to be 75%, which is very close to the 70% removed by SFE under the applied conditions. This suggests that the chemical methodology is capable of measuring the bioavailable fraction very accurately in this system.

Pressurized liquid extraction in determination of polychlorinated biphenyls and organochlorine pesticides in fish samples

Pressurized liquid extraction (PLE) is a relatively new technique applicable for the extraction of persistent organic pollutants from various matrices. The main advantages of this method are short time and low consumption of extraction solvent. The effects of various operational parameters (i.e. temperature of extraction, number of static cycles and extraction solvent mixtures) on the PLE efficiency were investigated in this study. Fish muscle tissue containing 3.2% (w/w) lipids and native polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and other related compounds was used for testing. Purification of crude extracts was carried out by gel permeation chromatography employing Bio-Beads S-X3. Identification and quantitation of target indicator PCBs and OCPs was performed by high-resolution gas chromatography (HRGC) with two parallel electron-capture detectors (ECDs). Results obtained by the optimized PLE procedure were compared with conventional Soxhlet extraction (the same extraction solvent mixtures hexane–dichloromethane (1:1 v/v) and hexane–acetone (4:1 v/v) were used). The recoveries obtained by PLE operated at 90–120 °C were either comparable to “classic” Soxhlet extraction (for higher-chlorinated PCB congeners and DDT group) or even better (for lower chlorinated analytes). The highest recoveries were obtained for three static 5 min extraction cycles.

Selective extraction of persistent organic pollutants from environmental matrices.

An attempt is made to determine the bioavailability of persistent organic pollutants (POP's) in environmental matrices. The approach is based on the use of the Hildebrand Solubility Parameter, and its individual parameters of hydrogen bonding, dispersion and polarity to select weak and strong solvents to extract POP's from soil matrices. The approach has been applied to both spiked soils and certified reference materials. Initial results indicate that it is possible to fractionate POP's from soil matrices based on their ability to be extracted from soil by particular solvents.

Pressurised liquid extraction of persistent organic pollutants in environmental analysis

This review updates our knowledge on pressurised liquid extraction, PLE (also known as accelerated solvent extraction and pressurised fluid extraction) of persistent organic pollutants such as polynuclear aromatic hydrocarbons and polychlorinated biphenyls from environmental matrices. The basic experimental set-up is presented, and parameters influencing the extraction process are discussed. PLE can be used for a broad range of applications, and clearly has the potential for replacing tedious classic extraction methods such as Soxhlet extraction.