Efficient analysis of selected estrogens using fabric phase sorptive extraction and high performance liquid chromatography-fluorescence detection

Exploring the potentialities of a biodegradable polymeric film in sample preparation: An optimized "white" protocol to extract and quantify emerging contaminants in water

BACKGROUND

The introduction of white analytical chemistry encourages the development of methods characterized by a balance among greenness, productivity/feasibility and analytical performances. In the environmental analysis of emerging contaminants (ECs), for which high sensitivity and specificity are mandatory, the use of green and sustainable sample preparation needs to be coupled to a reliable analytical determination. Herein, an extraction method based on the use of a biodegradable polymeric film (Mater-Bi) and coupled to LC-MS/MS analysis was developed for the sensitive determination of ECs in wastewater.

RESULTS

The interaction among a range of ECs and the Mater-Bi film (a commercially available patented blend of polybutylene-terephthalate, starch and fatty acids) was investigated by two sequential experimental designs, to simultaneously study several factors and optimize extraction efficiency. The final method, resembling a fabric phase sorptive extraction, involved pH and ionic strength modification of the sample, 1h extraction and desorption in ethanol. Satisfactory recoveries from real wastewater were obtained for sixteen analytes (56-116 %), as well as excellent precision (inter-day relative standard deviations below 10 % for most compounds). Matrix effect was in the range 88-116 % at the lower pre-concentration factor, but also acceptable in most cases at the higher pre-concentration factor. LODs in matrix, from 0.004 to 0.159 μg L-1, were lower than or comparable to those from recent studies employing green extraction procedures. The method demonstrated its applicability to samples from wastewater treatment plants, allowing quantification of pharmaceuticals and UV filters at the μg L-1 and ng L-1 levels, respectively.

SIGNIFICANCE

For the first time, the synthetic biopolymer Mater-Bi, so far unexplored for the use in analytical chemistry, was exploited for a green, simple and extremely cheap extraction protocol. The optimized method is suitable for several ECs, guaranteeing very good accuracy, precision and specificity, also thanks to the LC-MS/MS analysis. The evaluation by green and white analytical chemistry metrics highlighted its superiority to conventional extraction methods.

New fabric phase sorptive extraction for nondestructive analysis of heritage textile samples

Several types of pesticides used in museum collections over time become dangerous for people who may handle textile articles treated with such substances. In the case of the analysis of ancient, modern, and contemporary textile materials, it is particularly important to keep the artifacts intact, as they cannot be replaced. The need to use micro- or nondestructive techniques led to the development of methods such as solid-phase microextraction (SPME), liquid‒liquid dispersive microextraction (DLLME), and single-droplet microextraction (SDME). In this paper is described an optimized extraction method of three pesticides (malathion, methoxychlor, and permethrin) by creating a non-destructive solid phase extraction system on a textile support, abbreviated FPSE - 100 % cotton fabric coated with a sol-gel solution prepared from a polymer (PEG or PDMS). To obtain a suitable FPSE, the following parameters were evaluated: polymer selection (individual or mixture of polymers), acid catalyst (trifluoroacetic acid, acetic acid and hydrochloride acid), amount of polymer (1.0 g, 2.5 g or 5.0 g), polymerization time (30 min, 120 min and 240 min), ultrasonic bath temperature (40 °C and 70 °C), and type of bath to obtain the sol-gel (ultrasonic bath, water bath with stirring and mechanical stirrer). To complete the FPSE optimization, the influence of pesticide extraction time on FPSE and desorption from FPSE in ethyl acetate was also assessed. The pesticides extraction yields obtained for the laboratory textile samples are in the range of 52.7 %-128.0 %. The technique proposed in the manuscript proved to be effective as a nondestructive tool for evaluating and quantifying the presence of pesticides in textile museum collections. The approach described here reduces heritage object damage due to sampling compared to methods commonly employed and may represent a starting point for future research.

A facile fabric phase sorptive extraction method for monitoring chloramphenicol residues in milk samples

Determination of pharmaceutical active molecules in the biological matrices is crucial in various fields of clinical and pharmaceutical chemistry, e.g., in pharmacokinetic studies, developing new drugs, or therapeutic drug monitoring. Chloramphenicol (CP) is used for treating bacterial infections, and it's one of the first antibiotics synthetically manufactured on a large scale. Fabric phase sorptive extraction (FPSE) was used to determine Chloramphenicol antibiotic residues in milk samples by means of validated HPLC-DAD instrumentation. Cellulose fabric phases modified with polyethylene glycol-block-polypropylene glycol-block-polyethylene glycol triblock copolymer was synthesized using sol-gel synthesis approach (Sol-gel PEG-PPG-PEG) and used for batch-type fabric phase extractions. Experimental variables of the FPSE method for antibiotic molecules were investigated and optimized systematically. The HPLC analysis of chloramphenicol was performed using a C18 column, isocratic elution of trifluoroacetic acid (0.1%), methanol, and acetonitrile (17:53:30) with a flow rate of 1.0 mL/min. The linear range for the proposed method for chloramphenicol (r2 > 0.9982) was obtained in the range of 25.0-1000.0 ng/mL. The limit of detections (LOD) is 8.3 ng/mL, while RSDs% are below 4.1%. Finally, the developed method based on FPSE-HPLC-DAD was applied to milk samples to quantitatively determine antibiotic residues.

Exploiting the potential of fabric phase sorptive extraction for forensic food safety: Analysis of food samples in cases of drug facilitated crimes

Drug-facilitated crimes (DFCs) entail the use of a single drug or a mixture of drugs to render a victim unable. Traditionally, biological samples have been gathered from victims and conducting analysis to establish evidence of drug administration. Nevertheless, the rapid metabolism of various drugs and delays in analysis can impede the identification of such substances. For this, the present article describes a rapid, sustainable, highly efficient and miniaturized protocol for the identification and quantification of three sedative-hypnotic drugs namely diazepam, chlordiazepoxide and ketamine in alcoholic beverages and complex food samples (cream of biscuit, flavoured milk, juice, cake, tea, sweets and chocolate). The methodology involves utilizing fabric phase sorptive extraction (FPSE) to extract diazepam (DZ), chlordiazepoxide (CDP), and ketamine (KET), Subsequently, the extracted sample are subjected to analysis using gas chromatography-mass spectrometry (GC-MS). Several parameters, including type of membrane, pH, agitation time and speed, ionic strength, sample volume, elution volume and time, and type of elution solvent, were screened and thoroughly optimized. Sol-gel Carbowax 20M (CW-20M) has demonstrated most effective extraction efficiency for the target analytes among all evaluated membranes. Under optimal conditions, the method displayed linearity within the range of 0.3-10 µg mL-1 (or µg g-1), exhibiting a coefficient of determination (R2) ranging from 0.996 to 0.999. The limits of detection (LODs) and limits of quantification (LOQs) for liquid samples ranging between 0.020 and 0.069 µg mL-1 and 0.066-0.22 µg mL-1, respectively. Correspondingly, the LODs for solid samples ranged from 0.056 to 0.090 µg g-1, while the LOQs ranged from 0.18 to 0.29 µg g-1. Notably, the method showcased better precision, with repeatability and reproducibility both below 5% and 10%, respectively. Furthermore, the FPSE-GC-MS method proved effective in determining diazepam (DZ) in forensic food samples connected to drug-facilitated crimes (DFCs). Additionally, the proposed method underwent evaluation for its whiteness using the RGB12 algorithm.

A Review of the Analysis of Phthalates by Gas Chromatography in Aqueous and Food Matrices

As a commonly well-known industrial chemical, phthalates are produced in high volumes to be used in various consumer products (e.g., plasticizers, medical devices, construction materials, and toys) to enhance softness, durability, transparency, and flexibility. Phthalates are generally not chemically bonded to the polymer chain of the plastic in which they are mixed. Thus, they may leach, migrate, or evaporate into indoor/outdoor air, and foodstuffs. In this review, a comprehensive overview of several sample preparation methods coupled with gas chromatography for the analysis of phthalates in various kinds of complex matrices, with a focus on the last 20 years' worth of papers. The review begins by highlighting the environmental significance of phthalate pollution along with the various routes to their exposure to general population. Then, the discussion is extended to cover the pretreatment and extraction techniques for phthalates for their quantitation based on gas chromatographic approach. Finally, the present and future challenges for the detection of phthalates in aqueous and food matrices are discussed.

Performance Evaluation of Extraction Coatings with Different Sorbent Particles and Binder Composition

Binders are critical components used in the preparation of a range of extraction devices, including solid-phase microextraction (SPME) devices. While the main role of a binder is to affix the sorbent particles to the selected support, it is critical to select the optimal binder to ensure that it does not negatively impact the coating's particle sorption capability. This work presents the first comprehensive investigation of the interactions between binders and solid sorbent particles as these interactions can significantly impact the performance of the coating. Specifically, the findings presented herein provide a better understanding of the extraction mechanisms of composite coatings and new rules for predicting the particle adhesion forces and binder distribution in the coating. The influence of binder chemistry on coating performance is investigated by examining a selection of the most used binders, namely, polydimethylsiloxane (PDMS), polyacrylonitrile (PAN), poly(vinylidene difluoride) (PVDF), polytetrafluoroethylene amorphous fluoroplastics (PTFE AF 2400), and polybenzimidazole (PBI). The solid particles (e.g., hydrophilic-lipophilic balanced (HLB) and C18) used in this work were selected for their ability to provide optimal extraction coverage for a broad range of analytes. The results show that PDMS does not change the properties of the solid particles and that the binder occupies a negligible volume due to shrinking after polymerization, resulting in the solid particles making up most of the coating volume. Hence, the coating sorption characteristics correspond closely to the properties of the selected solid particles. On the other hand, the results also showed that PTFE AF 2400 can interact with the active surface of the sorbent, leading to the deactivation of the sorbent particles. Therefore, the extraction performance and permeability coefficients decrease as the size of the penetrant increases, indicating a rigid porous structure. The results of this study can aid in the optimization of SPME devices as they provide reference values that can be used to determine the optimal binder and the sorbent affinity for the targeted compounds. Finally, the present work also provides the broader scientific community with a strategy for investigating the properties of sorbent particle/binder structures and defines the characteristics of a good coating/membrane by analyzing all parameters such as kinetics, thermodynamic equilibria, and morphology.

Magnet Integrated Fabric Phase Sorptive Extraction (MI-FPSE): A Powerful Green(er) Alternative for Sample Preparation

Green(er) sample preparation technologies still dominate as the anticipated improvement in all analytical protocols. Separation scientists all over the world continuously strive to comply with the Green Analytical Chemistry (GAC) demands. To follow this trend, microextraction techniques are constantly evolving to bridge the gap between Green Analytical Chemistry and sample pretreatment. A research group from Florida International University, Miami, Florida has introduced fabric phase sorptive extraction (FPSE) in 2014 that was considered as a new milestone in microextraction technologies at that time. Two years later, the same research group introduced an advantageous innovative configuration that combines the stirring and extraction mechanism into a single sample preparation device, keeping all the benefits originally offered by classical FPSE. Magnet integrated fabric phase sorptive extraction (MI-FPSE) was eventually introduced as a new, advantageous implementation of FPSE. This device exhibits the advantageous role of the increase in extraction kinetics through sample diffusion, resulting in improved extraction efficiency of the microextraction device and supports the need for combining processes for better promotion and implementation of the principles of Green Analytical Chemistry. The applications of MI-FPSE are presented herein, showing the essential role that this technique can play in analytical and bioanalytical sample preparation.

Rapid Determination of Non-Steroidal Anti-Inflammatory Drugs in Urine Samples after In-Matrix Derivatization and Fabric Phase Sorptive Extraction-Gas Chromatography-Mass Spectrometry Analysis

Fabric phase sorptive extraction (FPSE) has become a popular sorptive-based microextraction technique for the rapid analysis of a wide variety of analytes in complex matrices. The present study describes a simple and green analytical protocol based on in-matrix methyl chloroformate (MCF) derivatization of non-steroidal anti-inflammatory (NSAID) drugs in urine samples followed by FPSE and gas chromatography-mass spectrometry (GC-MS) analysis. Use of MCF as derivatizing reagent saves substantial amounts of time, reagent and energy, and can be directly performed in aqueous samples without any sample pre-treatment. The derivatized analytes were extracted using sol−gel Carbowax 20M coated FPSE membrane and eluted in 0.5 mL of MeOH for GC-MS analysis. A chemometric design of experiment-based approach was utilized comprising a Placket−Burman design (PBD) and central composite design (CCD) for screening and optimization of significant variables of derivatization and FPSE protocol, respectively. Under optimized conditions, the proposed FPSE-GC-MS method exhibited good linearity in the range of 0.1−10 µg mL−1 with coefficients of determination (R2) in the range of 0.998−0.999. The intra-day and inter-day precisions for the proposed method were lower than <7% and <10%, respectively. The developed method has been successfully applied to the determination of NSAIDs in urine samples of patients under their medication. Finally, the green character of the proposed method was evaluated using ComplexGAPI tool. The proposed method will pave the way for simper analysis of polar drugs by FPSE-GC-MS.

High Performance Liquid Chromatography (HPLC) with Fluorescence Detection for Quantification of Steroids in Clinical, Pharmaceutical, and Environmental Samples: A Review

Steroids are compounds widely available in nature and synthesized for therapeutic and medical purposes. Although several analytical techniques are available for the quantification of steroids, their analysis is challenging due to their low levels and complex matrices of the samples. The efficiency and quick separation of the HPLC combined with the sensitivity, selectivity, simplicity, and cost-efficiency of fluorescence, make HPLC coupled to fluorescence detection (HPLC-FLD) an ideal tool for routine measurement and detection of steroids. In this review, we covered HPLC-FLD methods reported in the literature for the steroids quantification in clinical, pharmaceutical, and environmental applications, focusing on the various approaches of fluorescent derivatization. The aspects related to analytical methodology including sample preparation, derivatization reagents, and chromatographic conditions will be discussed.

Fabric Phase Sorptive Extraction for the Determination of Anthracyclines in Sewage

Anthracyclines are a group of antineoplastic compounds used to treat acute leukemia and other cancers, and they are excreted after consumption by patients. These chemicals are often found in sewage at very low concentration levels. For this reason, the development of sensitive analytical methodologies capable of determining them at low concentrations is of prime importance. A simple, fast and sensitive analytical method using fabric phase sorptive extraction (FPSE) followed by ultra-high performance liquid chromatography with fluorescence detection (UHPLC-FD) has been developed and validated for the extraction of anthracyclines from sewage samples. FPSE is a green, cheap, simple, selective and rapid sample preparation technique. The different parameters that affect the performance of the FPSE process, including extraction time, eluting solvent, elution time and pH, were optimized. The developed method showed satisfactory reproducibility, with intraday and interday RSD values lower than 15% for all the compounds and limits of detection between 0.1–0.15 µg·L−1. The unique combination of sample preparation by this micro-extraction technique with fluorescence detector have resulted in the satisfactory extraction of highly polar anthracyclines, without any noticeable matrix effect, a very common shortcoming of exhaustive sample preparation technique such as solid phase extraction (SPE) and mass spectrometry.

Fabric phase sorptive extraction combined with gas chromatography-mass spectrometry as an innovative analytical technique for the determination of selected polycyclic aromatic hydrocarbons in herbal infusions and tea samples

This study presents a fabric phase sorptive extraction (FPSE) protocol for the isolation and preconcentration of four selected polycyclic aromatic hydrocarbons from tea samples and herbal infusions, followed by their separation and quantification by gas chromatography-mass spectrometry (GC-MS). In FPSE, extraction of the target analytes is performed utilizing a flexible fabric substrate that is coated with a highly efficient sol–gel sorbent. In this work, eighteen different FPSE membranes were examined, with the highest extraction recoveries being observed with the sol–gel C₁₈ coated FPSE membrane. The main parameters that influence the adsorption and desorption of the PAHs were optimized and the proposed method was validated. The detection limits and the quantification limits were 0.08–0.17 ng mL⁻¹ and 0.25–0.50 ng mL⁻¹, respectively, for the different target compounds with a 10 mL sample. The relative standard deviations for intra-day and inter-day repeatability were less than 7.9% and 8.5%, respectively. The sol–gel C₁₈ coated FPSE membrane could be used for at least 5 subsequent sample preparation cycles. Finally, the proposed protocol was successfully employed for the determination of PAHs in a wide range of tea and herbal infusion samples.

A fabric phase sorptive extraction (FPSE) protocol for the isolation and preconcentration of four selected polycyclic aromatic hydrocarbons from tea samples and herbal infusions is presented, followed by their quantitative analysis by GC-MS.

Determination of synthetic opioids in oral fluid samples using fabric phase sorptive extraction and gas chromatography-mass spectrometry

New psychoactive substances (NPS) continue to emerge in the drug market every year, becoming a global threat to public health and safety. These compounds are mostly synthetic cannabinoids and designer cathinones. However, synthetic opioids have appeared on the recreational drug markets in recent years, particularly fentanyl and its derivatives ("fentanyls"). Fentanyl and its analogs are related to harmful intoxications and an increase in opioid-related mortality in many countries, such as in the United States and Europe in the last years. Taking the drug related global crisis into consideration, this work developed and validated an effective and sensitive method based on fabric phase sorptive extraction (FPSE) followed by gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of 11 fentanyl analogs in oral fluid samples. The extraction was carried out using a sol-gel Carbowax 20 M sorbent immobilized on 100% cellulose fabric substrate and using ethyl acetate as the desorption solvent. The limits of detection (LODs) and quantification (LOQs) ranged from 1 to 15 ng mL^-1 and 5 to 50 ng mL^-1, respectively. Intra-day and inter-day precision were found within 8.2% and 8.6%, respectively, while accuracy ranged from -5.5 to 9.1%, in accordance with the established criteria. The absolute recovery values were in the range of 94.5%-109.1%. The validated method demonstrated its great potential to detect and quantify fentanyl analogs in possible forensic work and off-site analysis in road traffic cases.

Novel Applications of Microextraction Techniques Focused on Biological and Forensic Analyses

In recent years, major attention has been focused on microextraction procedures that allow high recovery of target analytes, regardless of the complexity of the sample matrices. The most used techniques included liquid-liquid extraction (LLE), solid-phase extraction (SPE), solid-phase microextraction (SPME), dispersive liquid-liquid microextraction (DLLME), microextraction by packed sorbent (MEPS), and fabric-phase sorptive extraction (FPSE). These techniques manifest a rapid development of sample preparation techniques in different fields, such as biological, environmental, food sciences, natural products, forensic medicine, and toxicology. In the biological and forensic fields, where a wide variety of drugs with different chemical properties are analyzed, the sample preparation is required to make the sample suitable for the instrumental analysis, which often includes gas chromatography (GC) and liquid chromatography (LC) coupled with mass detectors or tandem mass detectors (MS/MS). In this review, we have focused our attention on the biological and forensic application of these innovative procedures, highlighting the major advantages and results that have been accomplished in laboratory and clinical practice.

Solventless Microextration Techniques for Pharmaceutical Analysis: The Greener Solution

Extensive efforts have been made in the last decades to simplify the holistic sample preparation process. The idea of maximizing the extraction efficiency along with the reduction of extraction time, minimization/elimination of hazardous solvents, and miniaturization of the extraction device, eliminating sample pre- and posttreatment steps and reducing the sample volume requirement is always the goal for an analyst as it ensures the method’s congruency with the green analytical chemistry (GAC) principles and steps toward sustainability. In this context, the microextraction techniques such as solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE), microextraction by packed sorbent (MEPS), fabric phase sorptive extraction (FPSE), in-tube extraction dynamic headspace (ITEX-DHS), and PAL SPME Arrow are being very active areas of research. To help transition into wider applications, the new solventless microextraction techniques have to be commercialized, automated, and validated, and their operating principles to be anchored to theory. In this work, the benefits and drawbacks of the advanced microextraction techniques will be discussed and compared, together with their applicability to the analysis of pharmaceuticals in different matrices.

Development of highly hydrophobic fabric phase sorptive extraction membranes and exploring their applications for the rapid determination of tocopherols in edible oils analyzed by high pressure liquid chromatography-diode array detection

Α novel, green, and facile fabric phase sorptive extraction (FPSE) prior to high pressure liquid chromatography with diode array detection (HPLC-DAD) methodology was developed for the efficient extraction and quantitative determination of tocopherols (α-, sum of (β+γ), and δ-) in edible oils. Among several highly hydrophobic FPSE membranes, sol-gel polycaprolactone-polydimethylsiloxane-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated polyester FPSE membrane was found as the most efficient in extracting tocopherol homologues from edible oil samples. To maximize the extraction efficiency of FPSE membrane, major parameters of FPSE including the membrane size, sample loading time, the choice of the appropriate elution solvent and the elution solvent volume, desorption time, and the influence of stirring were systematically optimized. The developed FPSE-HPLC-DAD methodology was validated and presented adequately low limits of detection (LODs) and limits of quantification (LOQs) over the ranges 0.05-0.10 μg/g, and 0.17-0.33 μg/g, respectively. The RSD% of the within-day and between-day assays were lower than 1.3, and 11.8, respectively, demonstrating good method precision. The trueness of the method was assessed by means of relative percentage of recovery and ranged between 90.8 and 95.1% for within-day assay, and between 88.7-92.8% for between-day assay. The developed methodology was applied in the analysis of edible oils.

Exploring sol-gel zwitterionic fabric phase sorptive extraction sorbent as a new multi-mode platform for the extraction and preconcentration of triazine herbicides from juice samples

Triazine herbicides are a class of common pesticides which are widely used to control the weeds in many agricultural crops. Although many studies have described methodologies for the determination of triazine herbicides in aqueous samples, the attention given to agricultural crops and their products is far more limited. In this study, a novel sol-gel zwitterionic multi-mode fabric phase sorptive extraction (FPSE) platform was developed for the matrix clean-up, extraction and preconcentration of five triazine herbicides from fruit juice samples prior to their determination by high performance liquid chromatography-diode array detection (HPLC-DAD). The novel zwitterionic multi-mode sorbent was characterized and its performance for fruit juice analysis was evaluated. Compared to other sol-gel sorbents, the novel zwitterionic sorbent helped cleaning all the acidic interferences from fruit juices. The herein reported FPSE protocol was optimized and validated. Under optimum conditions, the FPSE method showed good accuracy, precision and sensitivity. The limits of detection and limits of quantification for all analytes were 0.15 ng mL^-1 and 0.50 ng mL^-1, respectively. The enhancement factors of this method ranged between 36.7 and 51.8. The relative standard deviation for intra-day precision was below 5.6% and for inter-day precision was below 8.8%. Finally, the proposed FPSE-HPLC-DAD method was successfully employed for the analysis of various fruit juice samples.

Self-rotating stir mesh screen sorptive extraction for analyzing chlorpyrifos by ion mobility spectrometry

A mesh screen was electrochemically coated with polypyrrole and used as a sorptive extractor device, for the first time. This configuration acts in such a way that it is self-rotating in the presence of a magnetic force and can be used for extraction and concentration of analytes. Actually, applying a mesh screen instead of a bar or plate in sorptive extraction provided a more effective contact area between the sorptive materials and sample solution, resulting in higher sorption efficiency. The device performance was assessed by using chlorpyrifos pesticide as a model analyte. A thermal desorption unit was coupled to an ion mobility spectrometer and applied for evaporating the extracted analyte. Different parameters affecting the extraction efficiency during the electro-polymerization and the extraction process, including the time of electrodeposition, the concentration of pyrrole, oxalic acid and salt, temperature and time of extraction, and the stirring rate of the extractor device were investigated and optimized, simultaneously. The detection and quantification limits of the method were calculated to be 0.035 and 0.1 μg L^-1, respectively. The linear dynamic range obtained was from 0.1 to 20 μg L^-1, with a determination coefficient of 0.9984. The intra-day and inter-day-relative standard deviations (RSD, n = 3) were lower than 3% and 8%, respectively. Under the optimal conditions, the absolute recovery and the enrichment factor were found to be 97% and 5820, respectively. Finally, the relative recoveries of the proposed method were calculated to be in the range of 86-111% for spiked water, wastewater, and apple samples. The results obtained from the method were validated by EPA method 622.

Potential risk of BPA and phthalates in commercial water bottles: a minireview

The global water bottling market grows annually. Today, to ensure consumer safety, it is important to verify the possible migration of compounds from bottles into the water contained in them. Potential health risks due to the prevalence of bisphenol A (BPA) and phthalates (PAEs) exposure through water bottle consumption have become an important issue. BPA, benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) can cause adverse effects on human health. Papers of literature published in English, with BPA, BBP, DBP and DEHP detections during 2017, by 2019 by liquid chromatography and gas chromatography analysis methods were searched. The highest concentrations of BPA, BBP, DBP and DEHP in all the bottled waters studied were found to be 5.7, 12.11, 82.8 and 64.0 μg/L, respectively. DBP was the most compound detected and the main contributor by bottled water consumption with 23.7% of the Tolerable Daily Intake (TDI). Based on the risk assessment, BPA, BBP, DBP and DEHP in commercial water bottles do not pose a serious concern for humans. The average estrogen equivalent level revealed that BPA, BBP, DBP and DEHP in bottled waters may induce adverse estrogenic effects on human health.

Green bioanalytical sample preparation: fabric phase sorptive extraction

Fabric phase sorptive extraction (FPSE) is a recently introduced sample preparation technique that has attracted substantial interest of the scientific community dealing with bioanalysis. This technique is based on a permeable and flexible substrate made of fabric, coated with a sol-gel organic-inorganic sorbent. Among the benefits of FPSE are its tunable selectivity, adjustable porosity, minimized sample preparation workflow, substantially reduced organic solvent consumption, rapid extraction kinetics and superior extraction efficiency, many of which are well-known criteria for Green Analytical Chemistry. As such, FPSE has established itself as a leading green sample preparation technology of 21st century. In this review, we discuss the principal steps for the development of an FPSE method, the main method optimization strategies, as well as the applications of FPSE in bioanalysis for the extraction of a wide range of analytes (e.g., estrogens, benzodiazepines, androgens and progestogens, penicillins, anti-inflammatory drugs, parabens etc.).

Fabric phase sorptive extraction combined with high-performance liquid chromatography-photodiode array detection for the determination of tazarotene in gel dosage forms

Tazarotene, a member of the acetylenic class of retinoids, is a third-generation prescription topical retinoid sold as a cream, gel, or foam. In its gel or cream formulations, tazarotene is at a concentration of either 0.1 % or 0.05 %. Fabric phase sorptive extraction membranes are used to selectively isolate and preconcentrate target analytes from different sample matrices. In this study, the tazarotene gel formulation was directly applied to fabric phase sorptive extraction membranes and extracted through a mixture of acetonitrile and water (80:20, v/v) to obtain a clean product free of colloidal suspension of tazarotene gel formulation. The final solutions were injected into an HPLC system equipped with a Zorbax 5 μm Phenyl-Hexyl LC Column (250 × 4.6 mm). Injection volume was 50 μL and UV detection was performed at 326 nm. The flow rate was 1.0 mL min^-1 while using an isocratic elution with a mixture of ammonium acetate (50 mM) and methanol (15:85, v/v) as the mobile phase. The method was validated according to ICH guideline Q2 (R1) and successfully applied to gel formulations including 0.01 % tazarotene. This is the first reported application of fabric phase sorptive extraction in the analyses of gel formulations. The capability of fabric phase sorptive extraction membranes to clean up the sample matrix and prepare active pharmaceutical ingredients to be analyzed with acceptable recovery (>98.0 %) and reproducibility may encourage quality control laboratories to use fabric phase sorptive extraction in routine applications.

Fan-based device for integrated air sampling and microextraction

In this article, a new air sampler based on a conventional computer fan is presented and evaluated. The fan has a double role as it acts as the air pumping system and supports the sorptive phases, which are located on its blades. The compact design and the reduced energy consumption (it can operate with a standard cell phone charger) confers high portability to the device. Also, a simple alternative integrated into the fan is proposed for using an internal standard during the sampling, thus increasing the precision of the measurements. In this first communication, sol-gel Carbowax 20 M coated fabric phases are used as sorptive membranes thanks to their planar geometry, mechanical and thermal stability, and their versatility covering different interaction chemistries. After sampling, the fabric phases are placed in a headspace vial, which is finally analyzed by gas chromatography-mass spectrometry. The sampler has been characterized for the extraction of selected volatile organic compounds (chloroform, benzaldehyde, toluene, and cyclohexane) from air and its versatility has also been evaluated by the identification of semi-volatile compounds in working place (toluene and xylene in laboratory residue storage room) and biogenic volatile compounds in natural samples (terpenes in fresh pine needles and orange peel samples).

Simultaneous detection of diethylstilbestrol and estradiol residues with a single immunochromatographic assay strip

An immunochromatographic assay (ICA) based on competitive format was developed and validated for simultaneously rapid and sensitive detection of diethylstilbestrol (DES) and estradiol (E2) in milk and tissue samples. For this purpose, two monoclonal antibodies raised against those two estrogens were conjugated to gold nanoparticles and were applied to the conjugate pads of the test strip. The competitors of the DES-BSA/E2-BSA conjugates were immobilized onto a nitrocellulose membrane at two detection zones to form T1 and T2, respectively. The immunochromatographic assay had a visual detection limit of DES at 30 ng/g in milk powder, 25 ng/g in liquid milk, and 25 ng/g in shrimp tissue, respectively, and the results can be judged within 7-10 min. The visual detection limit of E2 was 75 ng/g in milk powder, 65 ng/g in liquid milk, and 60 ng/g in shrimp tissue, respectively, and the results can be judged within 3-4 min. It had advantages in easy operation without requiring sophisticated equipment and specialized skills. By testing thirty milk and shrimp tissue samples from the local market, the method was compared with the HPLC-MS / MS method, and there was no statistical difference between the two methods. Furthermore, the immunochromatographic assay had good specificity, simple procedure, and low cost. This protocol was well suited for the food safety monitoring and early warning.

Fate and distribution of benzotriazole UV filters and stabilizers in environmental compartments from Gran Canaria Island (Spain): A comparison study

Tourism is an economic sector of great importance worldwide. In coastal areas, this activity is associated with the use of personal care products, such as ultraviolet (UV) filters and stabilizers. Therefore, assessing their presence and the exposure of living organisms to the impact of this kind of pollutant in such areas could be especially important. The Canary Islands (Spain) are considered an outermost region, and their main economic activity is based on tourism, both national and international. Thus, this area could be remarkably vulnerable to this kind of pollution, and its characterization could be useful to infer conclusions for other similar regions. With this aim, the occurrence of organic UV filters and stabilizers in different environmental matrices in Gran Canaria Island is presented in this work. Six benzotriazole compounds, UV-P, UV-326, UV-327, UV-328, UV-329 and UV-360, were found in wastewater, seawater, sludge, sediment, seaweed and fish samples. The numerous studies devoted to establishing the distribution of these target compounds in many different matrices on a touristic and particularly overcrowded island such as Gran Canaria can be used to understand the pollution situation in similar locations. The works in which determination procedures using different extraction techniques were optimized and validated for the analysis of liquid and solid samples are summarized. They are critically discussed regarding their characteristics and analytical parameters. This research is of interest to environmental managers specializing in the conservation of coastal areas where tourism is an important industry since the active components of UV filters and stabilizers can bioaccumulate and biomagnify in the trophic chain.

Fabric Phase Sorptive Extraction: A Paradigm Shift Approach in Analytical and Bioanalytical Sample Preparation

Fabric phase sorptive extraction (FPSE) is an evolutionary sample preparation approach which was introduced in 2014, meeting all green analytical chemistry (GAC) requirements by implementing a natural or synthetic permeable and flexible fabric substrate to host a chemically coated sol-gel organic-inorganic hybrid sorbent in the form of an ultra-thin coating. This construction results in a versatile, fast, and sensitive micro-extraction device. The user-friendly FPSE membrane allows direct extraction of analytes with no sample modification, thus eliminating/minimizing the sample pre-treatment steps, which are not only time consuming, but are also considered the primary source of major analyte loss. Sol-gel sorbent-coated FPSE membranes possess high chemical, solvent, and thermal stability due to the strong covalent bonding between the fabric substrate and the sol-gel sorbent coating. Subsequent to the extraction on FPSE membrane, a wide range of organic solvents can be used in a small volume to exhaustively back-extract the analytes after FPSE process, leading to a high preconcentration factor. In most cases, no solvent evaporation and sample reconstitution are necessary. In addition to the extensive simplification of the sample preparation workflow, FPSE has also innovatively combined the extraction principle of two major, yet competing sample preparation techniques: solid phase extraction (SPE) with its characteristic exhaustive extraction, and solid phase microextraction (SPME) with its characteristic equilibrium driven extraction mechanism. Furthermore, FPSE has offered the most comprehensive cache of sorbent chemistry by successfully combining almost all of the sorbents traditionally used exclusively in either SPE or in SPME. FPSE is the first sample preparation technique to exploit the substrate surface chemistry that complements the overall selectivity and the extraction efficiency of the device. As such, FPSE indeed represents a paradigm shift approach in analytical/bioanalytical sample preparation. Furthermore, an FPSE membrane can be used as an SPME fiber or as an SPE disk for sample preparation, owing to its special geometric advantage. So far, FPSE has overwhelmingly attracted the interest of the separation scientist community, and many analytical scientists have been developing new methodologies by implementing this cutting-edge technique for the extraction and determination of many analytes at their trace and ultra-trace level concentrations in environmental samples as well as in food, pharmaceutical, and biological samples. FPSE offers a total sample preparation solution by providing neutral, cation exchanger, anion exchanger, mixed mode cation exchanger, mixed mode anion exchanger, zwitterionic, and mixed mode zwitterionic sorbents to deal with any analyte regardless of its polarity, ionic state, or the sample matrix where it resides. Herein we present the theoretical background, synthesis, mechanisms of extraction and desorption, the types of sorbents, and the main applications of FPSE so far according to different sample categories, and to briefly show the progress, advantages, and the main principles of the proposed technique.

A Critical Review of Analytical Methods for Comprehensive Characterization of Produced Water

Produced water is the largest waste stream associated with oil and gas production. It has a complex matrix composed of native constituents from geologic formation, chemical additives from fracturing fluids, and ubiquitous bacteria. Characterization of produced water is critical to monitor field operation, control processes, evaluate appropriate management practices and treatment effectiveness, and assess potential risks to public health and environment during the use of treated water. There is a limited understanding of produced water composition due to the inherent complexity and lack of reliable and standardized analytical methods. A comprehensive description of current analytical techniques for produced water characterization, including both standard and research methods, is discussed in this review. Multi-tiered analytical procedures are proposed, including field sampling; sample preservation; pretreatment techniques; basic water quality measurements; organic, inorganic, and radioactive materials analysis; and biological characterization. The challenges, knowledge gaps, and research needs for developing advanced analytical methods for produced water characterization, including target and nontarget analyses of unknown chemicals, are discussed.

A Novel Glass Fiber Coated with Sol-Gel Poly-Diphenylsiloxane Sorbent for the On-Line Determination of Toxic Metals Using Flow Injection Column Preconcentration Platform Coupled with Flame Atomic Absorption Spectrometry

A novel simple and sensitive, time-based flow injection solid phase extraction system was developed for the automated determination of metals at low concentration. The potential of the proposed scheme, coupled with flame atomic absorption spectrometry (FAAS), was demonstrated for trace lead and chromium(VI) determination in environmental water samples. The method, which was based on a new sorptive extraction system, consisted of a microcolumn packed with glass fiber coated with sol-gel poly (diphenylsiloxane) (sol-gel PDPS), which is presented here for the first time. The analytical procedure involves the on-line chelate complex formation of target species with ammonium pyrrolidine dithiocarbamate (APDC), retention onto the hydrophobic sol-gel sorbent coated surface of glass fibers, and finally elution with methyl isobutyl ketone prior to atomization. All main chemical and hydrodynamic factors, which affect the complex formation, retention, and elution of the metal, were optimized thoroughly. Furthermore, the tolerance to potential interfering ions appearing in environmental samples was also explored. Enhancement factors of 215 and 70, detection limits (3 s) of 1.1 μg·L^-1 and 1.2 μg·L^-1, and relative standard deviations (RSD) of 3.0% (at 20.0 μg·L^-1) and 3.2% (at 20.0 μg·L^-1) were obtained for lead and chromium(VI), respec tively, for 120 s preconcentration time. The trueness of the developed method was estimated by analyzing certified reference materials and spiked environmental water samples.

Exploring the Efficiency of UHPLC-Orbitrap MS for the Determination of 20 Pharmaceuticals and Acesulfame K in Hospital and Urban Wastewaters with the Aid of FPSE

Aside from the classical residues of persistent organic pollutants (POPs), the occurrence of emerging contaminants (ECs) in the environment has become a subject of increasing concern due to their harmful impact on the aquatic environment. Wastewater treatment plant (WWTP) effluents are major sources of environmental pollution. Therefore, data concerning their existence is required. In this study, twenty compounds representative of different drug groups considered ECs and belonging to antibiotics, antipsychotics, anti-inflammatory drugs plus acesulfame K were selected to be accurately detected and quantified with UHPLC–LTQ-Orbitrap MS in hospital and urban WWTP effluents. Chromatographic parameters (column efficiency, mobile phase, etc.), as well as mass spectrometry conditions concerning ionization mode and Orbitrap analysis (ESI options, mass resolving power, AGC target, tube lens, injection time), were evaluated. Moreover, a novel fabric phase sorptive extraction (FPSE) method based on fiber glass coated with PEG300 was employed as sample preparation process. Experimental parameters affecting extraction and desorption steps such as sample pH, extraction time, ionic strength, elution time and solvent have been optimized. The optimized methodology was validated providing excellent linearity (R2 > 0.99), and low detection and quantification limits up to 3.1 and 9.3 ng/L, for carbamazepine, respectively. Relative recoveries ranged from 81.1% to 114.0%, while a medium matrix effect for most of the target compounds occurred. Applying the above analytical method in effluents of WWTPs from NW Greece, nine compounds were quantified with concentrations that varied from 55.4 to 728.4 ng/L.

Investigating the Utility of Fabric Phase Sorptive Extraction and HPLC-UV-Vis/DAD to Determine Antidepressant Drugs in Environmental Aqueous Samples

Depression is considered to be one of the most prevalent mental disorders in humans. Antidepressant drugs are released in large concentrations and cause adverse effects on the environment and/or human health. Fabric Phase Sorptive Extraction (FPSE), a contemporary solid sorbent-handling technique, is a quick, sensitive, and simple analytical process. This paper describes a micro-extraction FPSE procedure coupled with High-Performance Liquid-Chromatography–Photodiode Array Detection (FPSE-HPLC–DAD) for the simultaneous extraction and analysis of five antidepressants, namely citalopram, clozapine, mirtazapine, bupropion and sertraline. Three fabric media (Whatman Cellulose filter, Whatman Microfiber Glass filter and Polylactic acid disks) and two different sol–gel sorbents (polyethylene glycol (PEG 300), alongside poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG 5.800)) were tested. The best FPSE device was observed to be the microfiber glass filter coated with PEG 300 sol–gel sorbent. In addition, the parameters that affect the efficiency of the process (FPSE media and sorbents, sample pH, extraction time, elution time, etc.) were optimized. The proposed methodology displays a linear range with absolute recovery values higher than 60%, RSD% of less than 13% and LOQs in the range between 1.9–10.7 μg·L−1. Finally, the method was applied in hospital and urban effluents and lake water samples, but none of the analytes were detected.

Fabric phase sorptive extraction for the determination of 17 multiclass fungicides in environmental water by gas chromatography-tandem mass spectrometry

A rapid environmental pollution screening and monitoring workflow based on fabric phase sorptive extraction-gas chromatography-tandem mass spectrometry (FPSE-GC-MS/MS) is proposed for the first time for the analysis of 17 widespread used fungicides (metalaxyl, cyprodinil, tolylfluanid, procymidone, folpet, fludioxonil, myclobutanil, kresoxim methyl, iprovalicarb, benalaxyl, trifloxystrobin, fenhexamid, tebuconazole, iprodione, pyraclostrobin, azoxystrobin and dimethomorph) in environmental waters. The most critical parameters affecting FPSE, such as sample volume, matrix pH, desorption solvent and time, and ionic strength were optimized by statistical design of experiment to obtain the highest extraction efficiency. Under the optimized conditions, the proposed FPSE-GC-MS/MS method was validated in terms of linearity, repeatability, reproducibility, accuracy and precision. To assess matrix effects, recovery studies were performed employing different water matrices including ultrapure, fountain, river, spring, and tap water at 4 different concentration levels (0.1, 0.5, 1 and 5 µg/L). Recoveries were quantitative with values ranging between 70-115%, and relative standard deviation values lower than 14%. Limits of quantification were at the low ng/L for all the target fungicides. Finally, the validated FPSE-GC-MS/MS method was applied to real water samples, revealing the presence of 11 out of the 17 target fungicides.

A simplified fabric phase sorptive extraction method for the determination of amphetamine drugs in water samples using liquid chromatography-mass spectrometry

Fabric phase sorptive extraction (FPSE) can directly extract the target analytes and simultaneously determine many similar substances from complicated sample matrices. Also, it has very high chemical stability. Therefore, we used fabric phase sorptive extraction to analyze three amphetamine drugs (amphetamine (AM), methamphetamine (MAM), and 3,4-methylenedioxymethamphetamine (MDMA)) in water. This was coupled with ultrahigh-performance liquid chromatography and tandem mass spectrometry. The effects of different sorbent chemistries such as sorption time, ratios of back-extraction solvents, back-extraction time, and the salt effect on the extraction efficiency were studied; the optimum operation conditions were determined. Medium polarity polar polymer-coated FPSE media were created using short-chain poly (tetrahydrofuran) (PTHF). This is the most efficient extraction media for the analytes of interest. Under the optimized conditions, the linear range of the three amphetamine drugs were 0.1–150.0 (AM, MAM) and 0.5–200 ng mL⁻¹ (MDMA). The correlation coefficients (γ) were 0.9947 (AM), 0.9925 (MAM), and 0.9918 (MDMA). The detection limits (LOD) were 0.025 ng mL⁻¹ for AM, 0.029 ng mL⁻¹ for MAM, and 0.01 ng mL⁻¹ for MDMA. The corresponding limit of quantification values (LOQ) were 0.083 ng mL⁻¹, 0.097 ng mL⁻¹, and 0.031 ng mL⁻¹, respectively. The recoveries were 73.4–91.6%, 82.6–95.4%, and 92.7–95.3%, respectively, and the relative standard deviations (RSD) were 1.65–6.88%, 1.38–6.11%, and 1.58–7.34%, respectively. Moreover, our method can be successfully applied for the analysis of amphetamines in wastewater samples, and at the same time, lays the foundation for the future detection of such substances.

Fabric phase sorptive extraction (FPSE) can directly extract the target analytes and simultaneously determine many similar substances from complicated sample matrices.

Development of an analytical methodology based on fabric phase sorptive extraction followed by gas chromatography-tandem mass spectrometry to determine UV filters in environmental and recreational waters

A novel method based on fabric phase sorptive extraction (FPSE) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been validated for the simultaneous determination of 11 UV filters (ethylhexyl salicylate, benzyl salicylate, homosalate, benzophenone-3, isoamylmethoxycinnamate, 4-methylbenzylidenecamphor, methyl anthranilate, etocrylene, 2-ethylhexylmethoxycinnamate, 2-ethylhexyl p-dimethylaminobenzoate, and octocrylene), in natural and recreational waters. Major experimental parameters affecting FPSE procedure have been optimized to obtain the highest extraction efficiency. Different types and sizes of sol-gel coated FPSE media, sample volume, extraction time, and type and volume of desorption solvent were evaluated. The optimal conditions involved the use of a (2.0 × 2.5) cm² FPSE device with PDMS based coating for the extraction of 20 mL of water for 20 min. The quantitative desorption of the target compounds was performed with 0.5-1 mL of ethyl acetate. The method was satisfactorily validated in terms of linearity, precision, repeatability and reproducibility. Recovery studies were performed at different concentration levels in real water matrices to show its suitability, obtaining mean values about 90% and satisfactory precision. LODs were at the low ng L^-1 in all cases. Finally, the validated FPSE-GC-MS/MS method was applied to different real samples, including environmental water (lake, river, seawater) and recreational water (swimming-pool), where 8 out of the 11 studied compounds were detected at concentrations between 0.12-123 μg L^-1. FPSE is proposed as an efficient and simple alternative to other extraction and microextraction techniques for the analysis of UV filters in waters. Since no matrix effects were observed, quantification could be carried out by conventional calibration with standard solutions, without the need to perform the complete FPSE procedure, thus allowing a higher throughput in comparison with other microextraction techniques.

Comparison of dried matrix spots and fabric phase sorptive extraction methods for quantification of highly potent analgesic activity agent (2R,4aR,7R,8aR)-4,7-dimethyl-2-(thiophen-2-yl)octahydro-2H-chromen-4-ol in rat whole blood and plasma using LC-MS/MS

The methods for quantification of highly potent analgesic agent (2R,4aR,7R,8aR)-4,7-dimethyl-2-(thiophen-2-yl)octahydro-2H-chromen-4-ol in rat whole blood and plasma were developed and validated using dried matrix spots (DMS) or fabric phase sorptive extraction (FPSE) techniques in combination with LC-MS/MS. 2-Adamantylamine hydrochloride was used as an internal standard (IS). Chromatographic separation was carried out on a reversed-phase column (2.0×75 mm, 5 μm) using water containing 0.1% formic acid and methanol containing 0.1% formic acid as mobile phases in gradient mode at a flow rate of 200 μL/min. The mass spectrometric detection was performed using electrospray ionization (ESI) in positive ion mode. MRM transitions were m/z 284.5 → 137.2/157.4 for the analgesic agent and m/z 152.3 → 93.1/107.2 for IS. Calibration curves were linear within 20-5000 ng/mL in dried plasma spots (DPS) or dried blood spots (DBS) experiments. The linearity was obtained in the range of 20-5000 ng/mL and 50-5000 ng/mL for plasma-FPSE and blood-FPSE experiments, respectively. The intra- and inter-day accuracy and precision did not exceed acceptable limits. The mean extraction recovery (%) was 26 for DPS, 25 for DBS, 38 for plasma-FPSE, 31 for blood-FPSE.