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Automated primary amine-based supramolecular solvent microextraction with monoterpenoid as coacervation agent before high-performance liquid chromatography
Abstract
The phenomenon of the formation of a supramolecular solvent based on a primary amine during dispersion in the aqueous phase of a homogeneous mixture containing both an amphiphile (primary amine) and a coacervation agent (monoterpenoid) was presented. In this case, the addition of a solid monoterpenoid during microextraction was not required. The established approach has the potential for automation based on a flow system, since only liquid phases are involved in the formation of a supramolecular solvent. An automated primary amine-based supramolecular solvent microextraction technique with monoterpenoid as a coacervation agent was developed. The microextraction procedure was carried out inside a mixing chamber of a flow-batch system. Dispersion of the amphiphile and coacervation agent mixed solution in the phase of the aqueous sample was performed by using air bubbles supplied by a peristaltic pump. The technique was applied to the separation and preconcentration of bisphenol A from beverages for its chromatographic determination as a model analytical method. The supramolecular solvent precursors mixed solution contained both 1-hexylamine and menthol provided extract phase separation without centrifugation, high extraction recovery (90±8%), and compatibility of the extract phase with a mobile phase used for chromatographic analysis. The linear range was 2-5000 µg L⁻¹ with a determination coefficient of 0.999. The limit of detection calculated from a blank test based on 3σ was 0.7 µg L⁻¹. The limit of quantification calculated from a blank test based on 10 σ was 2 µg L⁻¹. The enrichment factor was found to be 10.4. The intra-day repeatability was less than 8% while inter-day repeatability was less than 10%; relative recovery values were in the range of 84-102%.
... In addition, a small amount of HFB can induce the formation of SUPRAS with a density greater than water, which facilitates collection after centrifugation. On the other hand, the preparation of SUPRASs typically involves amphiphilic molecules such as surfactants (anionic, cationic, or nonionic) [41], long-chain alcohols [42], long-chain carboxylic acids [43], and primary amines [44]. Farnesol (FO) is known as a secure molecule and has been used in the food, pharmaceutical, and cosmetic industries. ...
In this work, a new supramolecular solvent (SUPRAS) was prepared for the first time using hexafluorobutanol (HFB) and farnesol (FO). FO acts as an amphiphile and HFB as a coacervation inducer and density regulator. The method of dispersive liquid‐liquid microextraction followed by high‐performance liquid chromatography, supported by a vortex technique, was established using the prepared SUPRAS for the determination of Sudan dyes in aqueous samples. The extraction parameters, including FO content, HFB content, vortex time, salt addition, and solution pH, were thoroughly investigated and optimized. Under the optimized conditions, the linearity range is 10–750 ng/mL for Sudan I, and 10–1000 ng/mL for Sudan III and Sudan IV, respectively. The limits of detection for Sudan dyes were in the range of 0.8–3.1 ng/mL. The inter‐ and intra‐day relative standard deviations for Sudan dyes were in the range of 1.3%–4.1% and 0.2%–2.6%, respectively. Finally, the proposed method was applied to the determination of Sudan dyes in beverage and river water samples with recoveries ranging from 93.9% to 122.1%. Compared to conventional techniques for the extraction of Sudan dyes in real samples, the proposed method is simpler, faster, and more environmentally friendly.
... Recently, primary amines have been proposed as a new type of amphiphiles for SUPRAS formation and applied in chromatographic analysis of biological fluids (Bogdanova et al., 2020) and food samples (Bogdanova et al., 2022;Zhavoronok et al., 2023). These amphiphiles allow the extraction of analytes, based on van der Waals, electrostatic and hydrogen bonding interactions. ...
A green, efficient, and cost-effective bio-derived solvent-based automated dispersive liquid-liquid microextraction (BDS-ADLLME) method was developed in the present study. A liquid handling platform with only the pipetting function module was...
The design of a simple approach enabling the detection of bisphenol A (BPA) in water samples without the need for large amounts of solvents is of utmost importance. This paper reports a simple method for the separation, concentration, and quantification of BPA in water samples using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) after its microextraction into an in situ formed organic ion-associate (IA) liquid phase (LP). Novel IA phase components without conjugated double bonds, such as benzene rings, were investigated. Ethylhexyloxypropylamine hydrochloride and sodium dodecyl sulfate solutions were added to the water samples to form IAs. The aqueous phase and ion-associate liquid phase (IALP) were separated by centrifugation. The aqueous phase was removed, and the liquid phase was recovered and measured using HPLC-FLD or HPLC-electrochemical detection (ECD). The concentrated phase (IALP) had a relatively low viscosity and could be injected directly into the chromatograph without dissolving it in organic solvents. The detection limits for BPA by HPLC-FLD and HPLC-ECD were 0.009 and 0.3 µg L⁻¹, respectively.
A new type of hexafluorobutanol (HFB) primary alcohol ethoxylate (AEO)-based supramolecular solvent (SUPRAS) with density higher than water was prepared for the first time. HFB acted as AEO micelle-forming agent and density-regulating agent for SUPRAS formation. The prepared SUPARS was applied as extraction solvent for vortex-assisted direct microextraction of malachite green (MG) and crystal violet (CV) from lake sediment followed by high-performance liquid chromatographic determination. In the present work, SUPRASs prepared from AEO with different carbon chains as the amphiphiles and various coacervation agents were investigated. SUPARS formed from MOA-3 and HFB provided better extraction efficiency in comparison with other SUPRASs. Parameters influencing the extraction recovery of target analytes including the type and volume of AEO, volume of HFB, and vortex time were investigated and optimized. Under optimized conditions, linearity in the range of 2.0-400 μg g-1 for MG and 2.0-500 μg g-1 for CV with a correlation coefficient higher than 0.9947 was obtained. Limits of detection of 0.5 μg g-1 and relative standard deviations in the range of 0.9-5.8% were obtained. Compared to conventional extraction techniques for analysis of analytes in solid samples, the proposed method reduced sample usage and eliminated a primary extraction process by using a toxic organic solvent. The proposed method is simple, fast, and green and can be used for the analysis of target analytes in solid samples.
Since the implementation of Green Chemistry into analytical practice, significant efforts have been made to improve the sustainability of chemical analysis. These include reducing the use of hazardous chemicals and solvents, minimizing waste, and improving energy efficiency. Surfactants can be applied in chemical analysis as an environmentally friendly alternative to conventional solvents and chemicals. The use of surfactants can increase extraction efficiency by improving solubility, increasing selectivity, and reducing organic solvent consumption. In addition, surfactants can also reduce interference with the sample matrix and improve limits of detection. This review covers recent developments in surfactant-based extraction techniques, highlighting the use of surfactants in both liquid-phase and solid-phase extraction. The main principles of surfactant-based extraction methods are discussed, as well as their application as assisting agents or surface modifiers. The effects of deep eutectic solvents on surfactants micellization and the application of biocompatible surfactants are also discussed.
Bisphenol A (BPA) and its analogues are high-volume production organic synthetic compounds used in the synthesis of plastics. BPA has been categorized as an endocrine disrupting compound due to its ability to disrupt the hormonal makeup of living organisms. Air and dust are common sources of exposure of BPA for living organisms and most sources are anthropogenic and a result of thermal destruction of BPA containing materials, import and export of recyclable materials (especially e-waste) and fugitive emissions near BPA handling facilities. Current reports on BPA levels in air are limited and focused on effluent and surface water analysis (due to BPA’s propensity for environmental distribution to water). BPA’s presence in the developing part of the world is of particular concern due to lack of regulations and uncontrolled incinerations of domestic and imported waste. The current review summarizes up-to-date scientific literature on BPA’s occurrence in air, alongside physico-chemical and partitioning properties, persistence in air, seasonal variation, consideration of analytical strategies for BPA analysis and toxicological information. Globally reported air concentrations of BPA are included in this report, alongside reports on indoor air concentration of BPA and its analogues. As a special interest, levels of tetrabromobisphenol (TBBPA) are also mentioned. Overall, the highest outdoor air levels of BPA were reported in China (1.1 × 10⁶ pg/m³) near a low-tech e-waste recycling site, while examination of indoor dust revealed the presence of bisphenol analogues used in “BPA-free” products, raising questions about their safety. Due to their low volatility, BPA and its analogues are mainly present in air associated with particles; this has important implications for their persistence in air and the role of particulate matter (especially microplastics) in their transport and deposition. Current understanding of BPA’s particle association is limited, hence studying its potential for heterogeneous oxidative transformations is a pressing need required for accurate accounting of potential risk to human health and the environment.
About eight years ago, a new automation approach and flow technique called “Lab-In-Syringe” was proposed. It was derived from previous flow techniques, all based on handling reagent and sample solutions in a flow manifold. To date Lab-In-Syringe has evidently gained the interest of researchers in many countries, with new modifications, operation modes, and technical improvements still popping up. It has proven to be a versatile tool for the automation of sample preparation, particularly, liquid-phase microextraction approaches. This article aims to assist newcomers to this technique in system planning and setup by overviewing the different options for configurations, limitations, and feasible operations. This includes syringe orientation, in-syringe stirring modes, in-syringe detection, additional inlets, and addable features. The authors give also a chronological overview of technical milestones and a critical explanation on the potentials and shortcomings of this technique, calculations of characteristics, and tips and tricks on method development. Moreover, a comprehensive overview of the different operation modes of Lab-In-Syringe automated sample pretreatment is given focusing on the technical aspects and challenges of the related operations. We further deal with possibilities on how to fabricate required or useful system components, in particular by 3D printing technology, with over 20 different elements exemplarily shown. Finally, a short discussion on shortcomings and required improvements is given.
In this study, we used anion supramolecular solvent (SUPRAS) prepared from a mixture of an anionic surfactant, sodium dodecyl sulfate (SDS), and a cationic surfactant, tetrabutylammonium bromide (TBABr), as the extraction solvent in liquid phase microextraction (LPME) of paraquat (PQ) and diquat (DQ). The enriched PQ and DQ in the SUPRAS phase were simultaneously analyzed by ion-pairing reversed-phase high performance liquid chromatography. PQ and DQ were successfully extracted by LPME via electrostatic interaction between the positive charge of the quats and the negative charge of SUPRAS. PQ, DQ, and ethyl viologen (the internal standard) were separated within 15 min on a C18 column, with the mobile phase containing 1-dodecanesulfonic acid and triethylamine, via UV detection. The optimized conditions for the extraction of 10 mL aqueous solution are 50 μL of SUPRAS prepared from a mixture of SDS and TBABr at a mole ratio of 1:0.5, vortexed for 10 s at 1800 rpm, and centrifugation for 1 min at 3500 rpm. The obtained enrichment factors were 22 and 26 with limits of detection of 1.5 and 2.8 µg L⁻¹ for DQ and PQ, respectively. The precision was good with relative standard deviations less than 3.86%. The proposed method was successfully applied for the determination of PQ and DQ in vegetable samples and recoveries were found in the range of 75.0% to 106.7%.
Bisphenol A (BPA) is a synthetic compound broadly used in medical devices as well as in packaging of food and drinks. Recently, BPA toxicity has become of concern to environmental public health. Red wine that is susceptible to BPA contamination is an alcoholic beverage made from yeast fermentation of grapes in the presence of grape skins so as to extract phenolic compounds. The aim of this study was to validate an efficient, low cost, and time‐saving method for BPA determination in red‐wine beverage. To this end, a rapid and simple microextraction method is here proposed consisting in liquid–liquid separation assisted by a vortex–ultrasound–vortex procedure combined with gas chromatographic analysis (GC‐Fid or GC‐IT/MS). By means of a comparative study between real red‐wine matrix and synthetic hydroalcoholic solutions, different parameters related to the microextraction steps were investigated. The minimal amount of extraction solvent for a given volume of sample was calculated for both the systems. It was demonstrated that for red‐wine matrix, the extent of phase separation is strongly affected by some wine constituents and that separation can be tuned by varying the amount of the extraction solvent. This double vortex–ultrasound‐assisted method achieved high recovery of BPA and enrichment factor compared with other microextraction methods.
A sensitive, rapid, and efficient analytical method based on vortex-assisted liquid–liquid extraction combined with air-assisted liquid–liquid microextraction using high performance liquid chromatography-variable wavelength detection has been developed for the extraction and determination of bisphenol A and bisphenol B in canned doogh samples. In this method, the analytes are partitioned into n-hexane during liquid–liquid extraction and then they are enriched using the following air-assisted liquid–liquid microextraction procedure in a few microliters of an ammonia solution used as an extraction solvent. Under the optimum conditions, limits of detection and quantification were 0.82 and 0.54 and 2.7 and 1.5 ng mL⁻¹, for bisphenol A and bisphenol B, respectively. The extraction recoveries and enrichment factors of the selected analytes were 86 and 81% and 4300 and 4050, respectively. The relative standard deviations were lower than 9% for intra- (n = 6) and inter-day (n = 4) precisions at a concentration of 5 ng mL⁻¹ of each analyte. Finally, some canned doogh samples were effectively analyzed by the proposed method.
Bisphenol A (BPA) is a synthetic unit of polycarbonate polymers and epoxy resins, the types of plastics that could be found in essentially every human population and incorporated into almost every aspect of the modern human society. BPA polymers appear in a wide range of products, from liquid storages (plastic bottles, can and glass linings, water pipes and tanks) and food storages (plastics wraps and containers), to medical and dental devices. BPA polymers could be hydrolyzed spontaneously or in a photo- or temperature-catalyzed process, providing widespread environmental distribution and chronic exposure to the BPA monomer in contemporary human populations. Bisphenol A is also a xenoestrogen, an endocrine-disrupting chemical (EDC) that interferes with the endocrine system mimicking the effects of an estrogen and could potentially keep our endocrine system in a constant perturbation that parallels endocrine disruption arising during pregnancy, such as insulin resistance (IR). Gestational insulin resistance represents a natural biological phenomenon of higher insulin resistance in peripheral tissues of the pregnant females, when nutrients are increasingly being directed to the embryo instead of being stored in peripheral tissues. Gestational diabetes mellitus may appear in healthy non-diabetic females, due to gestational insulin resistance that leads to increased blood sugar levels and hyperinsulinemia (increased insulin production from the pancreatic beta cells). The hypothesis states that unnoticed and constant exposure to this environmental chemical might potentially lead to the formation of chronic low-level endocrine disruptive state that resembles gestational insulin resistance, which might contribute to the development of diabetes. The increasing body of evidence supports the major premises of this hypothesis, as exemplified by the numerous publications examining the association of BPA and insulin resistance, both epidemiological and mechanistic. However, to what extent BPA might contribute to the development of diabetes in the modern societies still remains unknown. In this review, I discuss the chemical properties of BPA and the sources of BPA contamination found in the environment and in human tissues. I provide an overview of mechanisms for the proposed role of bisphenol A in insulin resistance and diabetes, as well as other related diseases, such as cardiovascular diseases. I describe the transmission of BPA effects to the offspring and postulate that gender related differences might originate from differences in liver enzyme levels, such as UDP-glucuronosyltransferase, which is involved in BPA processing and its elimination from the organism. I discuss the molecular mechanisms of BPA action through nuclear and membrane-bound ER receptors, non-monotonic dose response, epigenetic modifications of the DNA and propose that chronic exposure to weak binders, such as BPA, may mimic the effects of strong binders, such as estrogens.
Bisphenol A (BPA) contamination in foods and beverages usually occurs as a result of migration from the packages that contain it. In this context, a simple, easy-to-use, and efficient method was developed for the spectrophotometric determination of BPA in food, milk, and water samples in contact with plastic products after preconcentration by ultrasonic-thermostatic-assisted cloud point extraction (UTA-CPE). The method is based on the charge transfer-sensitive complexation of BPA with 3-methylamino-7-dimethylaminophenothiazin-5-ium chloride (AzB) in the presence of cetyltrimethylammonium bromide (CTAB) at pH 8.5 and then extraction of the formed complex into the micellar phase of polyethylene glycol dodecyl ether (Brij 35). The effects of the analytical variables affecting complex formation and extraction efficiency were systematically studied and optimized. Under optimized conditions, a good linear relationship was obtained in the range of 1.2–160 μg L⁻¹ with a detection limit of 0.35 μg L⁻¹. After preconcentration of a sample of 20 mL, a sensitivity enhancement factor was found to be 180. The accuracy and reliability of the method were evaluated by recovery studies from the spiked quality control samples and intraday and interday precision studies. From the studies conducted, the extraction efficiency (E%) was in the range of 94–103% with a relative standard deviation lower than 5.2% (as RSD%, n = 5). The method was successfully applied to the preconcentration and determination of BPA from the selected sample matrices.
Graphical AbstractMigration of bisphenol A into the foodstuffs
A novel hyphenated method based on ultrasound-assisted dispersive liquid–liquid microextraction coupled to precolumn derivatization has been established for the simultaneous determination of bisphenol A, 4-octylphenol and 4-nonylphenol by high-performance liquid chromatography with fluorescence detection. Different parameters that influence microextraction and derivatization have been optimized. The quantitative linear range of analytes is 5.0–400.0 ng/L, and the correlation coefficients are more than 0.9998. Limits of detection for soft drinks and dairy products have been obtained in the range of 0.5–1.2 ng/kg and 0.01–0.04 μg/kg, respectively. RSDs of intra-day and inter-day precision for retention time and peak area are in the range of 0.47–2.31 and 2.76–8.79%, respectively. Accuracy is satisfactory in the range of 81.5–118.7%. RSDs of repeatability are in the range of 0.35–1.43 and 2.36–4.75% for retention time and peak area, respectively. Enrichment factors for bisphenol A, 4-octylphenol and 4-nonylphenol are 170.5, 240.3 and 283.2, respectively. The results of recovery and matrix effect are in the range of 82.7–114.9 and 92.0–109.0%, respectively. The proposed method has been applied to the determination of bisphenol A, 4-octylphenol and 4-nonylphenol in soft drinks and dairy products with much higher sensitivity than many other methods.This article is protected by copyright. All rights reserved
Supramolecular solvents are here proposed firstly as extractants in solid sample microextractions. The approach was evaluated by extracting flumequine (FLU) and oxolinic acid (OXO), two widely used veterinary medicines, from fish and shellfish muscle using a supramolecular solvent made up of decanoic acid (DeA) reverse micelles. The antibiotics were extracted in a single step (approximately 15 min), at room temperature, using 400 microL of solvent. After centrifugation, an aliquot of the extract was directly analyzed by liquid chromatography and fluorescence, without the need of clean-up or solvent evaporation. Contrary to the previously reported methods, both OXO and FLU were quantitatively extracted from fish and shellfish, independently of sample composition. The high extraction efficiencies observed for these antibiotics were a consequence of their amphiphilic character which resulted in the formation of DeA-OXO and DeA-FLU mixed aggregates. The quality parameters of this quantitative method including sensitivity, linearity, selectivity, repeatability, trueness, ruggedness, stability, decision limit and detection capability were evaluated according to the 2002/657/EC Commission Decision. Quantitation limits in the different samples analyzed (salmon, sea trout, sea bass, gilt-head bream, megrim and prawns) ranged between 6.5 and 22 microg kg(-1) for OXO and, 5 and 15 microg kg(-1) for FLU. These limits were far below the current maximum residue limits (MRLs) set by the European Union (EU) (i.e. 100 and 600 microg kg(-1), for OXO and FLU, respectively). The trueness of the method was determined by analyzing a Certified Reference Material (CMR, BCR-725) consisting of a lyophilised salmon tissue material. Recoveries for fortified samples (50-100 microg kg(-1) of OXO and 50-600 microg kg(-1) of FLU) and their relative standard deviations were in the intervals 99-102% and 0.2-5%, respectively. The repeatability, expressed as relative standard deviation, was 3.6% for OXO and 2.3% for FLU ([OXO]=[FLU]=200 microg kg(-1) and n=11).
Bisphenols and triclosan have been used in various products, and exposure to these chemicals may affect human health. The present study proposes a sensitive method for the determination of bisphenols A, F, S, and triclosan. The fiber was coated by amino/hydroxyl bifunctional microporous organic network and protected by polyvinylidene fluoride hollow fiber membrane for direct immersion solid phase microextraction. The limit of detection was 0.005 μg/L (μg/kg), and the recoveries were in the range of 76.7% to 107.5% (87.4% to 107.6%) for breast milk (infant formula), with intra-day and inter-day precisions less than 10.5% (7.3%) and 13.6% (8.4%), respectively. Fiber-to-fiber reproducibility of < 9.5% and a lifespan of > 100 cycles were obtained. The 95th percentile estimated daily intake of total bisphenols was close to temporary tolerable daily intake for infants fed by human milk, which highlighted the needs for further attention on human exposure to BPA and its substitutes.
Lab-In-Syringe direct immersion single drop microextraction is proposed as an automated sample pretreatment methodology and coupled online to HPLC with fluorescence detection for the determination of fluoroquinolones in environmental waters. For the first time, a drop of a natural deep eutectic solvent (NADES), synthesized from hexanoic acid and thymol, has been used as an extractant in automated single-drop microextraction. The extraction procedure was carried out within the 5 mL void of an automatic syringe pump. A 9-position head valve served the aspiration of all required solutions, air, waste disposal, and hyphenation with the HPLC instrument. Sample mixing during extraction was done by a magnetic stirring bar placed inside the syringe. Only 60 μL of NADES were required omitting toxic classical solvents and improving the greenness of the proposed methodology. By direct injection, linear working ranges between 0.1 and 5 μg L⁻¹ were achieved for all fluoroquinolones. The limit of quantification values and enrichment factors ranged from 20 ng L⁻¹ to 30 ng L⁻¹ and 35 to 45, respectively. Accuracies obtained from the analysis of spiked surface water and wastewater treatment plant effluent analysis at two concentration levels (0.5 and 4 μg L⁻¹) ranged from 84.6% to 119.7%, with RSD values typically <3%.
This work proposes for the first time, a metric tool that gives prominence to sample preparation. The developed metric (termed AGREEprep) was based on 10 categories of impact that were recalculated to 0-1 scale sub-scores, and then used to calculate the final assessment score. The criteria of assessment evaluated, among others, the choice and use of solvents, materials and reagents, waste generation, energy consumption, sample size, and throughput. Assessment was also based on the possibility to differentiate between criteria importance by assigning them weights. The assessment procedure was performed using an open access, intuitive software that produced an easy-to-read pictogram with information on the total performance and structure of threats. A compiled version of the open access software can be obtained from mostwiedzy.pl/AGREEprep. The applicability of AGREEprep was successfully demonstrated using six different methods as case studies.
An effective and simple surfactant-mediated microextraction of synthetic dyes from solid-phase food samples into the primary amine-based supramolecular solvents is presented for the first time. The developed procedure involved two stages: (i) an isolation of dyes from a solid-phase food sample into a micellar solution of the primary amine; (ii) a preconcentration of the extracted dyes into the supramolecular solvent phase generated from the obtained micellar solution under a coacervation process. The microextraction procedure was applied for the determination of synthetic dyes in confectionery, dried fruits, and spices samples. The supramolecular solvent formed from aqueous micelle aggregates of 1-octylamine due to coacervation induced by thymol provided maximum extraction recovery values for synthetic dyes. In the proposed two-stage extraction procedure the micellar solution of primary amine was a media for analytes isolation from solid-phase and their followed preconcentration.
Supramolecular solvent-based micro-extraction is a very important green technique for the isolation and pre-concentration of pesticide residues in food and environmental samples prior to their chromatographic analysis. The attractive features of supramolecular solvent-based micro-extraction include its simplicity, high pre-concentration factor, fastness, accuracy, low cost, less consumption of chemical reagents and environmental friendliness. The supramolecular solvent is generated from a ternary mixture of amphiphiles, water and a water miscible dispersion and coacervating solvent. Tehydrofuran is one of the solvents commonly used as both a dispersion solvent and a coacervating agent. This paper gives a recent comprehensive review on the application of alkanols as amphiphiles during supramolecular solvent-based micro-extraction of pesticide residues in food and environmental samples. Other researchers used long chain fatty acids as amphiphiles during pesticide analysis in food and environmental samples using supramolecular solvent-based micro-extraction, and this is discussed in this paper. The incorporation of ferrofluids in supramolecular solvents enables phase separation using a magnet instead of the time-consuming centrifugation technique. This paper also gives a detailed review of the application of ferrofluid-based supramolecular solvent micro-extraction of pesticide residues in food and environmental samples.
A phenomenon of supramolecular solvents formation in aqueous solutions containing primary amine and monoterpenoid compound is presented for the first time. A novel supramolecular solvent-based liquid phase microextraction was developed. In an aqueous phase primary amine formed isotropic solution due to formation of amphiphile supramolecular assembly. The phase separation was achieved by a coacervation process. The monoterpenoid phenol (thymol) acted as a coacervation agent and induced spontaneous in situ formation of tiny supramolecular solvent droplets. The applicability of the proposed microextraction procedure was demonstrated for the separation of sulfonamides from biological fluids (human plasma and serum). An obtained composition of supramolecular solvent (1-decylamine, thymol, water) promoted satisfactory extraction of polar analytes from aqueous phase. The calibration graphs were linear over the concentration ranges of 0.06–50 mg L⁻¹ for sulfamethoxazole, sulfamethazine and sulfapyridine. The limit of detection calculated from the blank tests based on 3σ was 0.02 mg L⁻¹ for all analytes. The total analysis time was 15 min.
We present a review of microextraction methods of separation and preconcentration, automated using the principles of equilibrium flow methods of analysis. The concepts and possibilities of automated methods of single-drop microextraction, dispersive microextraction, and homogeneous liquid–liquid extraction are discussed. The analytical potential of these methods is confirmed by some examples of analysis of food products and biological fluids.
A homogeneous liquid-liquid microextraction procedure based on primary amine phase separation was developed as a novel approach for the pretreatment of biological fluids. The procedure assumes primary amine dissolution in the aqueous sample phase, resulting in the creation of a homogeneous sample solution followed by phase separation and analyte extraction in the presence of a polar, water-miscible organic solvent. The phenomenon of primary amine phase separation from homogeneous aqueous solution in the presence of a polar, water-miscible organic solvent was studied in detail and applied for separation and preconcentration in chemical analysis for the first time. The suggested approach was used for the HPLC-UV determination of meropenem as a proof-of-concept analyte in human plasma and serum samples. Under optimal conditions, the detector response of meropenem was linear in the concentration range of 0.1–100.0 mg L⁻¹. The limit of detection was calculated from a blank test based on 3σ, was 0.03 mg L⁻¹.
In the present study, a method has been efficiently developed for the first time to determine nine bisphenol analogues [bisphenol A (BPA), bisphenol C (BPC), bisphenol AF (BPAF), bisphenol E (BPE), bisphenol F (BPF), bisphenol G (BPG), bisphenol M (BPM), bisphenol S (BPS), and bisphenol Z (BPZ)] together in bottled carbonated beverages (collected from the local market of Lucknow, India) using dispersive liquid-liquid microextraction process. This is based on solidification of floating organic droplet (DLLME-SFO) followed by injector port silylation coupled with gas chromatography-tandem mass spectrometry. The process investigated parameters of DLLME-SFO (including the type of extraction and disperser solvents with their volumes, effect of pH, ionic strength, and the sample volume), factors influencing to injection port derivatization like, collision energy, injector port temperature, derivatizing reagent with sample injection volume, and type of organic solvent. BPA, BPF, BPZ, and BPS were detected in each sample; whereas, other bisphenols were also detected in some carbonated beverage samples. After optimizing the required conditions, good linearity of analytes was achieved in the range of 0.097-100ngmL(-1) with coefficients of determination (R(2))≥0.995. Intra-day and inter day precision of the method was good, with relative standard deviation (% RSD)≤10.95%. The limits of detection (LOD) and limits of quantification (LOQ) values of all bisphenols were ranged from 0.021 to 0.104ngmL(-1) and 0.070 to 0.343ngmL(-1), respectively. The recovery of extraction was good (73.15-95.08%) in carbonated beverage samples and good enrichment factors (96.36-117.33) were found. Thus, the developed method of microextraction was highly precise, fast, and reproducible to determine the level of contaminants in bottled carbonated beverages.
Liquid-phase microextraction is one of the most studied sample pretreatment techniques in the last two decades. Apart from non-dispersive approaches, close attention has been paid to microextraction methodologies based on emulsion formation using solvent-assisted dispersion, kinetic energy, or induction of solvent-oversaturation. These techniques exhibit attractive characteristics, such as simplicity, rapidness, versatility, high extraction efficiency, and environmental friendliness, and have stimulated significant progress in laboratory sample treatment. Moreover, further automation of these methods enables improvements in reproducibility and sample-throughput, as well as coupling with modern analytical instrumentation.
Human health risk assessment is "the process to estimate the nature and probability of adverse health effects in humans who may be exposed to chemicals in contaminated environmental media, now or in the future." Currently, most data required for human risk assessment are derived from toxicological studies conducted in laboratory animals. The "Toxicology in the 21st Century" initiative expands the toxicity testing tools to include the development of alternative toxicity testing methods that examine pathways of toxicity (on a large scale) and the employment of dose-response and extrapolation modeling tools. While the latter methodology is in its infancy, several methodologies for dose-response and extrapolation modeling are more mature. Over the last decade, physiologically based pharmacokinetic (PBPK) modeling has gained acceptance as a computational tool for use in public health assessments. In this chapter, we present examples of quantitative structure-activity relationship (QSAR) models, physiologically based pharmacokinetic (PBPK) models, and biologically based dose response (BBDR) models that have been developed for use in public health assessments and advancing knowledge gained through in silico examinations of biological systems.
In the present study, an extraction, preconcentration, and determination method has been reported for some synthetic phenolic antioxidants and bisphenol A in honey samples using dispersive liquid–liquid microextraction technique followed by gas chromatography-flame ionization detection. The main factors influencing the extraction efficiency including extractive solvent type and volume as well as the volume of dispersive solvent, salt addition, and pH are evaluated in this study. Under the optimum extraction conditions, limits of detection and quantification for all target analytes were obtained in the ranges of 0.4–4.7 and 1.3–14 ng g−1, respectively. Enrichment factors and extraction recoveries were in the ranges of 144–186 and 72–93 %, respectively. The method precision was evaluated at 100 ng g−1 of each analyte, and the relative standard deviations were found to be less than 7.6 % for intra-day (n = 6) and less than 8.3 % for inter-days (n = 4). The proposed method has been successfully applied to the analysis of different honey samples and two analytes, butylated hydroxytoluene and butylated hydroxyanisole, were determined at nanogram per gram level in one honey sample.
A literature updated has been made on the academical studies focused on the social impact of environmental studies, paying attention to both, the quality of the information provided and the side effects of the methodology employed, also considering the importance of the analytical methodologies in the development of remediation processes and the key subject of the transmission of the environmental information to the policy makers and the general society.
A supramolecular solvent made up of reverse micelles of decanoic acid was proposed for the simple and
rapid extraction of Sudan I, II, III and IV from chilli-containing foodstuffs. The procedure involved the
extraction of minute quantities (0.5–1 g) of homogenised food sample with an aqueous solution contain-
ing 10% THF and 200 mg of decanoic acid, conditions under which the supramolecular solvent (around
330 lL) formed in situ and instantaneously. The overall sample treatment took about 30 min and several
samples could be simultaneously treated using conventional lab equipment. No clean-up or solvent evap-
oration were required before determination of Sudan dyes by liquid chromatography and photometric
detection. Extractions were independent of salt addition (up to 1 M), the temperature (up to 60 ?C)
and the pH (below 4) rendering the method robust. The detection limits of the method were 4.2, 2.7,
6.5 and 7.4 lg kg?1for Sudan I, II, III and IV, respectively. Recoveries obtained by applying this approach
to the analysis of six chilli-containing sauces fortified with Sudan dyes at the lg kg?1level were in the
interval 86–108% with relative standard deviations between 2% and 7%.
Food constitutes the primary route for human exposure to bisphenol A (BPA), one of the highest volume chemicals produced worldwide. The estrogenic properties of BPA, its wide dispersive use and the recent extensive literature describing low-dose BPA effects in animals, have raised concerns about its possible adverse effects on human health. A reliable health risk assessment of BPA relies basically on its unambiguous identification and accurate quantification in food, and the aim of the present review is to give an overview of the analytical methods reported so far for the determination of BPA in these matrices. Emphasis is placed on the main strategies developed for sample treatment, which usually consists of several laborious and time-consuming steps in order to achieve the required sensitivity and selectivity. Separation, identification and quantitation of BPA is today reliably made with mass spectrometric methods, namely liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS), and thus main attention is devoted to these techniques, but other methods using LC coupled to fluorescence or electrochemical detection, as well as immunochemical methods are also covered. Recent and expected future developments are discussed.
The purpose of this study was to establish a reliable, cost-effective, fast and simple method to quantify simultaneously both bisphenol A (BPA) and bisphenol B (BPB) in liquid food matrixes such as canned beverages (soft drinks and beers) and powdered infant formula using dispersive liquid-liquid micro-extraction (DLLME) with in-situ derivatisation coupled with heart-cutting gas chromatography-mass spectrometry (GC-MS). For the optimisation of the DLLME procedure different amounts of various extractive and dispersive solvents as well as different amounts of the derivative reagent were compared for their effects on extraction efficiency and yields. The optimised procedure consisted of the injection of a mixture containing tetrachloroethylene (extractant), acetonitrile (dispersant) and acetic anhydride (derivatising reagent) directly into an aliquot of beverage samples or into an aqueous extract of powdered milk samples obtained after a pretreatment of the samples. Given the compatibility of the solvents used, and the low volumes involved, the procedure was easily associated with GC-MS end-point determination, which was accomplished by means of an accurate GC dual column (heart-cutting) technique. Careful optimisation of heart-cutting GC-MS conditions, namely pressure of front and auxiliary inlets, have resulted in a good analytical performance. The linearity of the matrix-matched calibration curves was acceptable, with coefficients of determination (r2) always higher than 0.99. Average recoveries of the BPA and BPB spiked at two concentration levels into beverages and powdered infant formula ranged from 68% to 114% and the relative standard deviation (RSD) was <15%. The limits of detection (LOD) in canned beverages were 5.0 and 2.0 ng l(-1) for BPA and BPB, respectively, whereas LOD in powdered infant formula were 60.0 and 30.0 ng l(-1), respectively. The limits of quantification (LOQ) in canned beverages were 10.0 and 7.0 ng l-1 for BPA and BPB, respectively, whereas LOQ in powdered infant formula were 200.0 and 100.0 ng l(-1), respectively. BPA was detected in 21 of 30 canned beverages (ranging from 0.03 to 4.70 µg l(-1)) and in two of seven powdered infant formula samples (0.23 and 0.40 µg l(-1)) collected in Portugal. BPB was only detected in canned beverages being positive in 15 of 30 samples analysed (ranging from 0.06 to 0.17 µg l(-1)). This is the first report about the presence of BPA and BPB in canned beverages and powdered infant formula in the Portuguese market.
Bisphenol A (BPA), a contaminant which may be present in the coating of cans, was determined in 45 canned beverages and 21 canned food items from the Belgian market. Beverages had an average BPA concentration of 1.0 ng/ml, while canned foods had a higher average concentration of 40.3 ng/g. The amount of BPA present in food items was dependent on the type of can and sterilisation conditions rather than the type of food. For example, BPA was not detected in non-canned beverages (<0.02 ng/ml), while non-canned food items had a very low average concentration of 0.46 ng/g. Using detailed information from the Belgian food consumption survey, the BPA intake of adults through canned foods and beverages was estimated to be 1.05 µg/day or 0.015 µg/kg body weight/day (assuming an average adult weight of 70 kg). Intake assessments, based on urinary metabolite concentrations from the literature, resulted in slightly higher BPA intakes (range 0.028-0.059 µg/kg body weight/day). This suggests that sources other than canned foods and beverages contribute to BPA exposure in humans.
Amphiphile-based supramolecular solvents (ASSs), which are water immiscible liquids consisting of supramolecular aggregates in the nano- and micro-scale regimes dispersed in a continuous phase, were assessed for the extraction of trace contaminants in liquid foods. The ASS selected was made up of reversed micelles of decanoic dispersed in tetrahydrofuran (THF)-water and the contaminants used as a model were bisphenol A (BPA), ochratoxin A (OTA) and benzo(a)pyrene (BaPy). The influence of matrix components on the extractant solvent production, extraction recoveries and actual concentration factors was investigated by using commercial foods such as wine and wine-based products, beer, soft drinks and tea and coffee brews, and/or aqueous synthetic solutions containing specific food matrix components. The method involved the addition of decanoic acid (80mg) and THF (0.8-1.7mL) to the food sample (15mL), stirring of the mixture for 5min, centrifugation for 10min and analysis of 10-20microL of the extract by liquid chromatography coupled to fluorimetry for OTA and BaPy or to mass spectrometry for BPA. No clean-up of the crude extracts was required for any of the samples analysed. The quantification limits for the contaminants (14-31ngL(-1), 0.37-0.39ngL(-1) and 562-602ngL(-1) for OTA, BaPy and BPA, respectively) were far below their respective European legislative threshold limits. Recoveries for food samples were in the ranges 79-93%, 90-96% and 78-82% for OTA, BaPy and BPA, respectively, with relative standard deviations ranging from 1 to 7%, and actual concentrations factors between 65 and 141. The methods developed were applied to the determination of the target compounds in a variety of commercial foods. OTA was found in vinegar, must and beer samples, the concentrations ranging from 92 to 177ngL(-1), BaPy was quantified in samples of tea and coffee at concentrations between 1.5 and 16.6ngL(-1) whereas BPA was detected in two canned soft drinks and quantified in one of them (tea beverage) at a level of 2.3microgL(-1).
Flavors and Fragrances, in: Ullmann’s Encyclopedia of Industrial Chemistry
- K.-G Fahlbusch
- F.-J Hammerschmidt
- J Panten
- W Pickenhagen
- D Schatkowski
- K Bauer
- D Garbe
- H Surburg