Determination of Bisphenol A in Food and Environmental Samples Using Combined Solid-Phase Extraction–Dispersive Liquid–Liquid Microextraction with Solidification of Floating Organic Drop Followed by HPLC

Deep eutectic solvent for the extraction of polycyclic aromatic compounds in fuel, food and environmental samples

Polycyclic aromatic compounds (PACs) encompass a wide variety of organic analytes that have mutagenic and carcinogenic potentials for human health and are recalcitrant in the environment. Evaluating PACs levels in fuel (e.g., gasoline and diesel), food (e.g., grilled meat, fish, powdered milk, fruits, honey, and coffee) and environmental (e.g., industrial effluents, water, wastewater and marine organisms) samples are critical to determine the risk that these chemicals pose. Deep eutectic solvents (DES) have garnered significant attention in recent years as a green alternative to traditional organic solvents employed in sample preparation. DES are biodegradable, have low toxicities, ease of synthesis, low cost, and a remarkable ability to extract PACs. However, no comprehensive assessment of the use of DESs for extracting PACs from fuel, food and environmental samples has been performed. This review focused on research involving the utilization of DESs to extract PACs in matrices such as PAHs in environmental samples, NSO-HET in fuels, and bisphenols in foods. Chromatographic methods, such as gas chromatography (GC) and high-performance liquid chromatography (HPLC), were also revised, considering the sensibility to quantify these compound types. In addition, the characteristics of DES and advantages and limitations for PACs in the context of green analytical chemistry principles (GAC) and green profile based on metrics provide perspective and directions for future development.

Three-dimensional flower-like SnS2 materials for dispersive solid-phase extraction of endocrine-disrupting phenols

In this study, three-dimensional flower-like tin disulfide materials were prepared, and a highly efficient dispersive solid-phase extraction method was developed using the obtained three-dimensional tin disulfide adsorbents for the preconcentration and determination of six endocrine-disrupting phenols in combination with high-performance liquid chromatography-ultraviolet detection. Several important experimental parameters influencing extraction efficiency were investigated, including the amount of adsorbent, ultrasound time, sample solution pH, sample volume, type of elution solvent, desorption time, and the number of desorption times. Under the optimized experimental conditions, the developed method showed good linearity with the determination coefficients of 0.993-0.998 in the linear range of 0.5-400 ng/ml and low limits of detection in the range of 0.15-1.0 ng/ml, as well as satisfactory intra-day and inter-day precisions with relative standard deviations of 0.1-9.8%. Finally, the proposed method was successfully applied for the enrichment and determination of trace endocrine-disrupting phenols in milk, tea beverage, and plastic bottled water samples, and acceptable recoveries were obtained from 70.1% to 119.1% under four different spiked concentration levels. The results showed that the three-dimensional tin disulfide materials had great potential for the extraction of endocrine-disrupting phenols contaminants in environmental and food samples.

An indirect method for the analysis of bisphenol A, as a Mn(III)-chelate complex, in milk samples by ultrasound assisted-cloud point extraction/flame atomic absorption spectrometry

A method for indirect determination of bisphenol A (BPA), as a Mn(III)-chelate complex, in milk samples by flame atomic absorption spectrometry (FAAS) was developed. The method was based on cloud point extraction with ultrasound assistance (UA-CPE). In the pre-concentration step by UA-CPE, the ternary complex selectively formed between BPA and Mn(III)-oxalate at pH 5.0 was extracted into the mixed micellar phase of ionic and nonionic surfactants, cetyltrimethylammonium bromide (CTABr) and polyethylene glycol tert-octylphenyl ether (Triton X-114) as a sensitivity enhancer and extractant. After phase separation by centrifugation, the separated extract was diluted with acidic methanol and analyzed by FAAS. The reproducibility of the signal in the detection step especially at low concentrations was greatly improved by the use of polyvinyl alcohol (PVA) as a stabilizer. Using indirect Mn-responses by FAAS, the main variables affecting the extraction efficiency were evaluated and optimized. Under optimized conditions, the calibration graph was highly linear in the range of 0.8-130 μg L^-1 with limits of detection and quantification of 0.23 and 0.76 μg L^-1, intra- and inter-day precisions in the range of 2.8-5.2% and 3.8-7.2%, and recovery in the range of 94.2-98.5% (10, 25, 100 μg L^-1, n: 5 and 3 × 5). From pre-concentration of a 35 mL sample by UA-CPE, the pre-concentration factor was found to be 70 with a 41-fold sensitivity improvement. The matrix effect was greatly reduced by deproteinization with trichloroacetic acid (TCA) and 20-fold dilution of milk samples before analysis. The method accuracy was checked by analysis of trace BPA in milk samples via a calibration curve in solvent and a matrix-matched calibration curve prepared from sample extracts. The results were in the range of 2.1-7.3 μg L^-1 and 2.0-7.0 μg L^-1 without any matrix effect. According to the Student's t-test, there is not a statistically significant difference between the results found by using the two calibration curves. Finally, it can be concluded that the method is suitable for detecting BPA in milk based products at concentrations far below the specific migration limit (SML) of 600 μg L^-1.

A Mixture of Endocrine Disruptors and the Pesticide Roundup® Induce Oxidative Stress in Rabbit Liver When Administered under the Long-Term Low-Dose Regimen: Reinforcing the Notion of Real-Life Risk Simulation

Humans are exposed to xenobiotic mixtures daily through the long-term, low-dose regimen. Investigations designed to simulate this exposure profile approach the real-life risk simulation (RLRS) idea of modern toxicology. The purpose of the present study was to investigate the effects of 12-month exposure of New Zealand rabbits to a xenobiotic mixture comprising seven endocrine disruptors (EDs), which are chemical substances raising great concerns for human health, as well as the herbicide glyphosate, and its commercial formulation Roundup^®, on blood and tissues redox status. It is reported herein that at the systemic level, the administration of the EDs mixture induced perturbations of blood redox homeostasis at 3 months, whereas at 6 and 12 months, it activated redox adaptations. Contrariwise, exposure to glyphosate and Roundup^®, individually, caused mainly disturbances of blood redox equilibrium. At the tissue level, particularly in the liver, the administration of both the EDs mixture and Roundup^® induced oxidative stress, whereas glyphosate did not affect it. The RLRS notion appears to be confirmed through these findings. Indeed, the administration of the EDs mixture and Roundup^®, under the long-term, low-dose regimen, elicited detrimental effects on the redox status of the liver, a crucial tissue with a valuable biological role in the detoxification of organisms from xenobiotics.

Counter Current Salting-out Homogenous Liquid-liquid Extraction and Dispersion Liquid-liquid Microextraction Based on the Solidification of Floating Organic Drop Followed by High-performance Liquid Chromatography for the Isolation and Preconcentration of Pesticides from Fruit Samples

BACKGROUND

Pesticides are widely used to control pests and prevent diseases in crops, including cereals, vegetables, and fruits. Due to factors such as the persistence of pesticides, bioaccumulation, and potential toxicity, the pesticide residues monitoring in foodstuffs is very important.

OBJECTIVE

In the current research, we proposed a novel approach to counter current salting-out homogenous liquid-liquid extraction (CCSHLLE) combined with dispersive liquid-liquid microextraction based on the solidification of floating organic drop (DLLME-SFO) in pesticides from aqueous samples for the isolation and preconcentration, which were evaluated prior to analysis as real samples by high-performance liquid chromatography-ultraviolet detection (HPLC-UV).

METHODS

In brief, sodium chloride was applied as a separation reagent, which is filled in a small glass column, through which a combination of an aqueous solution (here we could say as juice of fruit) and passing of acetonitrile. In this process, the droplets rose through the column and a separated layer would be formed on what has remained from aqueous phase. Following that, acetonitrile as the organic phase combined with 50.0 µL of extraction solvent. To further enrich the analytes, the mixture was injected into five milliliters of a 4% sodium chloride solution and placed in a tube for the DLLME-SFO.

RESULTS

Under optimal conditions, the dynamic linear range of 0.5-500 μg/L, extraction recovery of 65-85%, enrichment factors of 108-142, and limit of detection as 0.2-0.4 μg/L were obtained for the organophosphorus pesticides. In addition, the repeatability and reproducibility in the five replicate of the pesticides measurements (100 μg/L) are within the ranges of 3.5-5.1% and 4.5-6.3%, respectively.

Vortex-assisted natural deep eutectic solvent dispersive liquid-liquid microextraction based on the solidification of a floating organic drop for the determination of benzoic acid and sorbic acid in condiments

A simple, inexpensive, reliable and environmentally friendly method based on vortex-assisted dispersive liquid-liquid microextraction combined with solidification of a floating organic drop (VA-DLLME-SFO) followed by high performance liquid chromatography with a diode array detector (HPLC-DAD) was developed to determine benzoic acid (BA) and sorbic acid (SA) in ketchup and powder bags of instant noodles. Hydrophobic natural deep eutectic solvents (NADESs), as the microextraction solvent, were prepared with ternary components. Acetic acid can reduce the viscosity of hydrophobic NADESs and vortex can promote the dispersion of NADESs in aqueous solvents. In the DLLME process, several key parameters were optimized, including the type and volume of hydrophobic NADES, pH value, vortex time and salt content. Meanwhile, these parameters were assessed using response surface methodology based on the Box-Behnken design (BBD). Under optimal conditions, the developed method showed good linearity in the selected range (r², 0.9997). The limits of detection were 0.2 μg mL^-1 and 0.07 μg mL^-1 for BA and SA, respectively. Recoveries were in the range of 82.21% to 102.70% and the relative standard deviations (intra-day and inter-day precisions) were less than 5.66%. The proposed method was successful in analyzing BA and SA in ketchup and powder bags of instant noodles.

A sensitive and fast approach for voltammetric analysis of bisphenol a as a toxic compound in food products using a Pt-SWCNTs/ionic liquid modified sensor

A sensitive and fast approach has been introduced for the voltammetric sensing of bisphenol A based on modification of a paste electrode with Pt-SWCNTs and 1-ethyl-3-methylimidazolium n-butylsulfate as a highly conductive binder. The new sensor was used to determine the concentration of bisphenol A in food products in I-V mode. The Pt-SWCNTs nanocomposite was synthesized through the polyol method and its morphology was evaluated by field emission scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy techniques. The determining factors influencing the sensing performance, i.e., pH and mediators used in the modification process were optimized in the first step and the results showed that at a pH of 7.0, a modified paste containing 9% (w:w) nanocomposite and 20% (v:v) 1-ethyl-3-methylimidazolium n-butylsulfate formed catalytic properties enhancing the oxidation signal of bisphenol A by 5.9 folds. Current density investigation clearly confirmed the conductivity of Pt-SWCNTs and 1-ethyl-3-methylimidazolium n-butylsulfate in the paste matrix. In addition, fabricated sensor showed considerable sensing behavior for bisphenol A in the concentration range of 0.5 nM-180 μM with a detection limit of 0.2 nM. In the final step, using standard addition technique, the ability of fabricated sensor for sensing bisphenol A in food products was evaluated, and the results confirmed improved performance of the modified electrodes.

Air-assisted liquid-liquid microextraction based on the solidification of floating deep eutectic solvents for the simultaneous determination of bisphenols and polycyclic aromatic hydrocarbons in tea infusions via HPLC

Deep eutectic solvents (DESs) are a new class of green "designer solvent"; its physicochemical properties can be easily tuned by adjusting DES' constituents, chemical ratio and water content. In this study, three hydrophobic DESs with low viscosity, low density, and melting points close to room temperature were designed and synthesized. Based on these DESs, an air-assisted liquid-liquid microextraction technique was developed based on the solidification of floating DESs for the simultaneous determination of bisphenols and polycyclic aromatic hydrocarbons (PAHs) via HPLC. The microextraction parameters were optimized via the Plackett-Burman design and response surface methodologies. The method shows satisfactory linearity (R² ≥ 0.9928), a low limit of detection (0.16-0.75 μg L^-1) and satisfactory precision (≤2.3%), and was successfully applied for the simultaneous determination of bisphenols and PAHs from tea infusions with satisfactory recoveries (82.0-116.6%). This method is simple, rapid, economical, environmentally compatible, dispersive solvent-frees and centrifugation-free, and has promising applications in food safety.

Application of the electropolymerized poly(3,4-ethylenedioxythiophene) sorbent for solid-phase microextraction of bisphenols

A new, simple, and effective procedure using poly(3,4-ethylenedioxythiophene)/lignosulfonate electropolymerized sorbent solid-phase microextraction (PEDOT/LS-SPME) combined with LC-MS/MS for determination of bisphenols in environmental water samples was developed. Various parameters influencing the performance of the analytical procedure including the type of sorbent, electropolymerization time, sorbent preconditioning time, extraction time, desorption (time and solvent), and sample pH were investigated and optimized. Under optimal conditions the proposed method allowed us to achieve good precision (n = 5) between 6.0 and 12.1%. The limits of detection were equal to 0.17 μg L-1 for BPA, 0.16 μg L-1 for BPF, 0.07 μg L-1 for BPE, 0.05 μg L-1 for BPB, and 0.027 μg L-1 for BPAF. The proposed method was successfully applied for the determination of bisphenols in aqueous environmental samples.

Plasticisers and preservatives in commercial milk products: A comprehensive study on packages used in the Spanish market

A comprehensive study on packaging used in commercially available milk products from Spanish markets has been presented. Concentrations of four phthalates, seven parabens and BPA were determined in forty-two milk products. Eleven brands and five types of packaging (metallic aluminium bag, carton, high-density polyethylene, metal pail and polyethylene terephthalate) were included in the study. BPA showed the lowest concentrations (8.3 pg/g f.w.), far below those of phthalates (6431 pg/g f.w.) and parabens (6234 pg/g f.w.). Metallic aluminium bags were the least migrating packaging (considering plasticisers and monomers) followed by HDPE bottles, in the case of phthalates. Parabens showed their highest concentrations for fresh-milk samples. Levels found were far below the specific migration limits established by the EU and the cumulative hazard index was lower than 1, indicating that adverse health effects were not expected. In general, the results found in Spanish samples were lower than those reported in other countries.

Bisphenol A Analogues in Food and Their Hormonal and Obesogenic Effects: A Review

Bisphenol A (BPA) is the most well-known compound from the bisphenol family. As BPA has recently come under pressure, it is being replaced by compounds very similar in structure, but data on the occurrence of these BPA analogues in food and human matrices are limited. The main objective of this work was to investigate human exposure to BPA and analogues and the associated health effects. We performed a literature review of the available research made in humans, in in vivo and in vitro tests. The findings support the idea that exposure to BPA analogues may have an impact on human health, especially in terms of obesity and other adverse health effects in children.

Organic Analysis of Environmental Samples Using Liquid Chromatography with Diode Array and Fluorescence Detectors: An Overview

This overview is focused to provide an useful guide of the families of organic pollutants that can be determined by liquid chromatography operating in reverse phase and ultraviolet/fluorescence detection. Eight families have been classified as the main groups to be considered: carbonyls, carboxyls, aromatics, phenols, phthalates, isocyanates, pesticides and emerging. The references have been selected based on analytical methods used in the environmental field, including both the well-established procedures and those more recently developed.

Data on concentrations of polycyclic aromatic hydrocarbons (PAHs) in roasted and fried chicken - A case study: Bushehr, Iran

In the present data article, the presence and amount of 16 polycyclic aromatic hydrocarbons (PAHs) were surveyed in Iranian roasted and fried chicken in Bushehr restaurants. For data collection, 73 samples (including 36 Roasted chicken and 37 Fried chicken samples) were collected from local restaurants and various retail outlets of Bushehr, Iran. The concentrations of 16 PAHs were determined by gas chromatography-mass spectrometry (GC–MS). Results indicated that the total PAHs level was ranged from 4.20 to 32.29 mg/kg and 2.06–19.65 µg/kg in Roasted and Fried chicken, respectively. The differences in PAHs levels were observed among charcoal and gas-roasted samples as well as between chicken fried with different oil types. benzo[a] pyrene(BaP), an appropriate marker for occurrence and potential toxicity of PAHs food matrixes was found in all roasted samples ranged from 1.41–5.71 mg/kg and all fried samples in range of 0.9–3.32 µg/kg. Moreover, unsaturated fatty acid (UFA) and saturated fatty acid (SFA) ratios in the in the used vegetable oils had an important role in the generation of PAHs in fried chicken.

Persistent sample circulation microextraction combined with graphite furnace atomic absorption spectroscopy for trace determination of heavy metals in fish species marketed in Kermanshah, Iran, and human health risk assessment

BACKGROUND

Persistent sample circulation microextraction (PSCME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was developed as a high pre-concentration technique for the determination of heavy metals in fish species. In this method, a few microliters of organic solvent (40.0 µL carbon tetrachloride) was transferred to the bottom of a conical sample cup. Then 10.0 mL of aqueous solution was transformed to fine droplets while passing through the organic solvent. At this stage, metal-ligand hydrophobic complex was extracted into the organic solvent. After extraction, 20 µL of extraction solvent was injected into the graphite tube using an auto-sampler.

RESULTS

Under optimal conditions, enrichment factors and enhancement factor were in the range of 180-240 and 155-214, respectively. The calibration curves were linear in the range of 0.03-200 µg kg^-1 and the limits of detection (LODs) were in the range of 0.01-0.05 µg kg^-1 . Repeatability (intra-day) and reproducibility (inter-day) for 0.50 µg L^-1 Hg and 0.10 µg L^-1 Cd and Pb were in the range of 3.1-4.2% (n = 7) and 4.3-6.1% (n = 7), respectively.

CONCLUSION

Potential human health risk assessment was conducted by calculating estimated weekly intake (EWI) of the metals from eating fish and comparison of these values with provisional tolerable weekly intake (PTWI) values. EWI data for the studied metals through fish consumption were lower than the PTWI values. © 2017 Society of Chemical Industry.

Development of a liquid-phase microextraction based on the freezing of a deep eutectic solvent followed by HPLC-UV for sensitive determination of common pesticides in environmental water samples

In this research, a new extraction method based on liquid-phase microextraction and the freezing of deep eutectic solvent has been developed for the determination of pesticides in water prior to their analysis by HPLC-UV.