SPME Fiber Research Articles

New solid phase microextraction fibers with green clay coating via radio frequency magnetron sputtering for detecting low-polar compounds in water samples

BackgroundDeveloping highly sensitive and selective measurement techniques to detect trace compounds in diverse matrices is a significant challenge in analytical chemistry. These techniques must adhere to green chemistry principles by minimizing organic solvent use, simplifying sample preparation, and streamlining process steps. Additionally, there is a growing need for sustainable analytical methods due to increased environmental awareness. The problem addressed in this work is the need for an eco-friendly and efficient method for the extraction and detection of trace organochlorine pesticides in water samples. ResultsWe employed SPME using a novel clay thin film sorbent, deposited on a nickel-titanium alloy wire via magnetron sputtering. Montmorillonite clay was chosen for its excellent adsorption properties and eco-friendly nature, aligning with green chemistry principles. The approach involved coating the SPME fiber with hydrophobic modified montmorillonite clay, followed by silylation. The method was tested for extracting 12 model organochlorine pesticides, including BHC, lindane, and DDT, demonstrating high isolation efficiency. The coated thin film and its silylation modification were characterized using standard spectroscopic techniques, confirming the successful creation of a new adsorbent phase. The direct immersion SPME approach achieved relative recoveries ranging from 65 % to 99 %, with reproducibility (RSD) below 6 %. This method provided low detection limits (10–15 ng L−1) and quantitation limits (32–50 ng L−1). SignificanceOur approach offers an eco-friendly, highly efficient solution for the extraction and detection of trace organochlorine pesticides. The significant improvement in recovery rates and reproducibility, combined with low detection and quantitation limits, underscores the potential of this method to enhance analytical practices in environmental monitoring and public health. Furthermore, the use of sustainable materials and processes aligns with global efforts to reduce environmental impact in analytical chemistry.

New Materials for Thin-Film Solid-Phase Microextraction (TF-SPME) and Their Use for Isolation and Preconcentration of Selected Compounds from Aqueous, Biological and Food Matrices.

Determination of a broad spectrum of analytes, carried out with analytical instruments in samples with complex matrices, including environmental, biological, and food samples, involves the development of new and selective sorption phases used in microextraction techniques that allow their isolation from the matrix. SPME solid-phase microextraction is compatible with green analytical chemistry among the sample preparation techniques, as it reduces the use of toxic organic solvents to the minimum necessary. Over the past two decades, it has undergone impressive progress, resulting in the development of the thin-film solid-phase microextraction technique, TF-SPME (the thin-film solid-phase microextraction), which is characterized by a much larger surface area of the sorption phase compared to that of the SPME fiber. TF-SPME devices, in the form of a mostly rectangular metal or polymer substrate onto which a thin film of sorption phase is applied, are characterized, among others, by a higher sorption capacity. In comparison with microextraction carried out on SPME fiber, they enable faster microextraction of analytes. The active phase on which analyte sorption occurs can be applied to the substrate through techniques such as dip coating, spin coating, electrospinning, rod coating, and spray coating. The dynamic development of materials chemistry makes it possible to use increasingly advanced materials as selective sorption phases in the TF-SPME technique: polymers, conducting polymers, molecularly imprinted polymers, organometallic frameworks, carbon nanomaterials, aptamers, polymeric ionic liquids, and deep eutectic solvents. Therefore, TF-SPME has been successfully used to prepare analytical samples to determine a broad spectrum of analytes in sample matrices: environmental, biological, and food. The work will be a review of the above-mentioned issues.

Regarding Bioanalysis Lasting a Few Minutes: Automated Cooling-SPME and Fast-GC for Urinary 2-Phenyl-2-Propanol Monitoring.

An innovative SPME head space GC-MS method, in cooling mode, using a fully automated routine, was developed to detect 2-phenyl-2-propanol, a representative urinary metabolite of cumene. Following an acid hydrolysis and derivatization step with lowered quantities of reagents, acetic anhydride and pyridine, a 30 μm polydimethylsiloxane SPME fiber was used to sample derivatized 2-phenyl-2-propanol, such as benzenemethanol,α,α-dimethyl-acetate, from the headspace. Performances of the method, optimized through experimental design, provide an LOD of 0.034 mg/L and an LOQ 0.10 mg/L, with a short sampling time necessary per sample. The method, developed on standard solutions, will be applied to both occupationally exposed and non-exposed populations.

EXPLORING BEE VENOM VOL ATILES: A PROMISING AVENUE FOR CYSTIC FIBROSIS

Bee venom, a complex mixture of bioactive compounds, has demonstrated anti-inflammatory, antimicrobial, and immunomodulatory properties. Notably, the volatiles released by bee venom components have garnered attention for their potential in respiratory-related disease conditions. Cystic fibrosis (CF) is a challenging disorder, characterized by a genetic mutation affecting the CFTR protein, leading to the production of thick and sticky mucus in various organs, particularly the lungs and digestive system, and necessitating innovative therapeutic approaches. This research explored both bee venom volatiles’ chemical composition and the effects on airway inflammation and mucus viscosity in CF patients by in silico methods. GC/MS analyses with various SPME fibers have conducted the identification of 67 distinct components in volatile compounds of bee venom. For CW/DVB, CAR-PDMS, and DVB-PDMS fibers, the compounds identified in the highest amounts were perilla alcohol (42.21%), tetradecane (11.48%), and 1,2-benzenedicarboxylic acid, 1,2-bis(2-methylpropyl) ester (39.98%), respectively. In silico analyses subsequently indicated that these components exhibit anti-inflammatory effects by modulating key cytokines and reducing inflammatory markers in CF airways. This research highlights the potential of bee venom volatiles as a novel therapeutic avenue for managing CF symptoms. Harnessing the unique properties of bee venom may offer new perspectives in the development of targeted therapies for individuals affected by cystic fibrosis.

Assessing residual fragrances on skin after body washing: Optimization of an analytical method using solid-phase microextraction coupled with gas chromatography-mass spectrometry.

The aim of this study is to develop and optimize a method for evaluating the persistence of residual fragrance after body washing, addressing a significant requirement in the development of personal care products. The main objective is to establish a reliable, sensitive and reproducible analytical technique to assess fragrance longevity on skin post-use of body wash products. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) is used to analyse residual fragrances. We investigate the extraction efficiencies of various SPME fibres and compare different methods for sampling skin-emitted fragrances, including tape stripping and sealed glass funnels. A controlled body-washing procedure is implemented to standardize the cleansing process. Our findings indicate that the relative standard deviation for measuring five distinct fragrances is within the range of 3%-14%, highlighting the precision of the method. A notable variance exists in the extraction efficiency of fragrances using different types of SPME fibres, with some exhibiting over a threefold difference. Furthermore, the glass funnel method for fragrance collection demonstrates an 11.7 times greater sensitivity to galaxolide than that of the tape-stripping method. Residual fragrances with base notes as the main components can be detected on the skin up to 24 h after body washing. The optimized method for residual fragrance evaluation developed in this study offers a robust tool for analysing fragrance components persisting on the skin for up to 24 h post-wash. This advancement facilitates a deeper understanding of fragrance longevity in personal care products, enabling comparative analyses between different products.

Wearable solid-phase microextraction sampling for enhanced detection of volatile analytes in human ears

BackgroundInvestigating ear at molecule level is challenging task, since there is a lack of molecular detection by traditional diagnosis techniques such as otologic endoscopy, ear swab culture, and imaging diagnostic technique. Therefore, new development of noninvasive, highly sensitive, and convenient analytical method for investigating human ears is highly needed. ResultsWe developed a wearable sampling device for extracting trace analytes in ear by fixing solid-phase microextraction fibers into modified earmuffs (SPME-in-earmuffs). After sampling, SPME fiber was coupled with gas chromatography-mass spectrometry (GC-MS) for identification and quantification of extracted analytes. Enhanced detection of various analytes such as volatile metabolites, exposures, and therapeutic drugs of ears were demonstrated in this work. Particularly, sport-induced metabolic changes such as fatty acids, aldehyde compounds and oxidative produces were found from human ears using this method. Acceptable analytical performances were obtained by using this newly developed method for detecting ear medicines, e.g., low limit of detection (LOD, 0.005–0.021 ng/mL) and limit of quantification (LOQ, 0.018–0.071 ng/mL), excellent linear dynamic responses (R2 > 0.99, ranging from 0.050–8.00 ng/mL), good relative standard deviations (RSDs, 13.19 % ∼ 21.40 %, n = 6) and accuracy (84.43–150.18 %, n = 6) at different concentrations. SignificanceFor the first time, this work provides a simple, convenient, and wearable microextraction method for enhanced detection of trace volatiles in human ears. The enclosed space between ear and earmuff allows headspace SPME sampling of volatile analytes, and thus provides a new wearable method for monitoring ear metabolites and human exposures, showing potential applications in human health, disease diagnosis, and sport science.

Comparison of kumquat (Fortunella spp.) volatiles using various SPME fibres followed by GC/MS techniques and determination of the total phenol and antioxidant compounds

Comparison of kumquat (<i>Fortunella</i> spp.) volatiles using various SPME fibres followed by GC/MS techniques and determination of the total phenol and antioxidant compounds

Analysis and Stability Study of Isoeugenol in Aquaculture Products by Headspace Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry.

Headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry (HS-SPME-GC-MS) offers an alternative analysis method for isoeugenol (an active ingredient in fish sedatives) that avoids the use of organic solvents, simplifies sample preparation, and can be fully automated. This work focuses on developing and evaluating an HS-SPME-GC-MS method for isoeugenol in aquaculture samples and testing the stability of isoeugenol itself. Because of isoeugenol's relatively low volatility, more polar SPME fiber coatings (polyacrylate and polydimethylsiloxane/divinylbenzene) had better performance and the headspace extractions took over 30 min to reach equilibrium. Additionally, it was found that isoeugenol was relatively unstable compared to a deuterated standard (d3-eugenol) in the presence of water. To address this, after the fish samples were homogenized with water, they were heated at 50 °C for 1 h prior to analysis for equilibration. By using the method developed in this work, isoeugenol's detection limits in multiple aquaculture matrices (shrimp, tilapia, and salmon) were in the low ng/g range (<15 ng/g), well below the target testing level (200 ng/g). Additionally, by adding d3-eugenol as an internal standard, excellent linearity (R2 > 0.98), accuracy (97-99% recoveries), and precision (5-13% RSDs) were all achieved.

Fabrication of MXene/chitosan/polyurea nanocomposite decorated on a graphenized substrate for electro-enhanced solid-phase microextraction of diclofenac followed by its determination using differential pulse voltammetry.

A novel solid-phase microextraction fiber based on MXene-chitosan-polyurea (MXene/CS/EPPU) nanocomposite decorated on a graphenized pencil lead fiber (MXene/CS/EPPU/GPLF) was prepared and utilized for electro-enhanced solid-phase microextraction (EE-SPME) of diclofenac (DCF) in biological samples. After extraction and desorption of DCF, it was determined by differential pulse voltammetry (DPV). For this purpose, the working electrode was prepared by deposition of the mentioned MXene/CS/EPPU nanocomposite onto the graphenized pencil lead. The synthesized SPME fiber was characterized using scanning electron microscopy and X-ray diffraction techniques. The effect of various parameters influencing the extraction and the desorption process were investigated, including applied voltage in the extraction and desorption steps, extraction and desorption times, and pH. The developed method exhibited a rather wide linearity in the range 2-1200 ng mL-1 (R2 = 0.985) for the determination of DCF in plasma samples. The limit of detection and the limit of quantification for plasma samples were estimated to be 0.58 and 1.9 ng mL-1 based on the 3Sb/m and 10Sb/m definitions, respectively. The method's accuracy and applicability have been evaluated by the analysis of plasma samples, leading to the relative recoveries in the range 87.0% and 98.0% with the relative standard deviations lower than 3.1%.

Simultaneous and sensitive detection of methylparaben and its metabolites by using molecularly imprinted solid-phase microextraction fiber array technique

BackgroundMethylparaben (MP), a commonly used antibacterial preservative, is widely used in personal care products, foods, and pharmaceuticals. MP and its metabolites are easy to enter the water environment, and their exposure and accumulation have negative effects on the ecological environment and human health, and have endocrine disrupting activity and potential physiological toxicity. It is still the primary issue of environmental analysis and ecological risk assessment to develop simple and reliable methods for simultaneous sensitive detection of these compounds in environmental water. ResultsIn this paper, a flexible molecularly imprinted fiber array strategy is proposed for simultaneous enrichment and detection of trace MP and its four main metabolites. The experimental results showed that the three-fiber imprinted fiber array constructed by MP imprinted fiber had the best effect on the simultaneous enrichment of these five target analytes. The enrichment capacity of the imprinted fiber array was 214–456 times, 314–1201 times and 38–685 times that of commercial PA, PDMS and PDMS/DVB fiber arrays, respectively. The limit of detection (LOD) of this method was 0.033 μg L−1. The spiked recovery rate was 86.78–113.96 %, and RSD was less than 9.17 %. In addition, this molecularly imprinted SPME fiber array has good stability, long service life and can be used repeatedly at least 100 times. SignificanceThis molecularly imprinted fiber array strategy can flexibly assemble different molecularly imprinted SPME fibers together, effectively improve the enrichment ability and detection sensitivity, and achieve simultaneous selective enrichment and detection of several analytes. This is an easy, efficient and reliable method for monitoring several trace analytes simultaneously in intricate environmental matrices.

Rapid screening of acetylcholinesterase active contaminants in water: A solid phase microextraction-based ligand fishing approach

Effect-directed analysis (EDA) has been increasingly used for screening toxic contaminants in the environment, but conventional EDA procedures are often time-consuming and labor-extensive. This challenges the use of EDA for toxicant identification in the scenarios when quick answers are demanded. Herein, a solid phase microextraction ligand fishing (SPME-LF) strategy has been proposed as a rapid EDA approach for identifying acetylcholinesterase (AChE) active compounds in water. The feasibility of ligand fishing techniques for screening AChE active chemicals from environmental mixtures was first verified by a membrane separation method. Then, SPME fibers were prepared through self-assembly of boronic acid groups with AChE via co-bonding and applied for SPME-LF. As AChE coated SPME fibers selectively enriched AChE-active compounds from water, comparing sorbing compounds by the SPME fibers with and without AChE coating can quickly distinguish AChE toxicants in mixtures. Compared with conventional EDA, SPME-LF does not require repeating sample separations and bioassays, endowing SPME-LF with the merits of low-cost, labor-saving, and user-friendly. It is believed that cost-efficient and easy-to-use SPME-LF strategy can potentially be a rapid EDA method for screening receptor-specific toxicants in aquatic environment, especially applicable in time-sensitive screening.

Ultra-stable Co3O4/NiCo2O4 double-shelled hollow nanocages as headspace solid-phase microextraction coating for enhanced capture of polychlorinated biphenyls

Polychlorinated biphenyls (PCBs) are persistent toxic pollutants that tend to accumulate in food and cause damage to human health. This work reports the ultra-sensitive detection of PCBs in beverage samples (green tea, honey, and bottled drinking water) by headspace solid-phase microextraction (HS-SPME) coupled with a gas chromatography-flame ionization detector (GC-FID). The Ultra-stable Co3O4/NiCo2O4 double-shelled hollow nanocages (DSHNC) as SPME fiber coating were synthesized with pyrolysis of zeolitic imidazolate framework-67/layered double hydroxide precursor. The fiber coating material Co3O4/NiCo2O4 DSHNC demonstrated excellent thermal stability (＞1000 °C) and long usage lifespan (≥160 times). The extract ability to polar PCBs was significantly enhanced by oxygen-containing groups, π-π stacking, and electrostatic interaction. Experiments results illustrated that the adsorption is controlled by chemical adsorption with a monolayer molecular adsorption. The HS-SPME-GC-FID method possessed good linearity (R2 ≥ 0.9961) in the linear range of 0.10–50000 pg·mL−1 and low detection limits (0.03–1.5 pg·mL−1). The enrichment factors were determined between 6884 and 9765. The method was successfully applied to enrich PCBs in real samples and obtained a good recovery rate in the range of 78.26–112.1 %.

Metabolic profiling of bacteria with the application of polypyrrole-MOF SPME fibers and plasmonic nanostructured LDI-MS substrates

Here we present application of innovative lab-made analytical devices such as plasmonic silver nanostructured substrates and polypyrrole-MOF solid-phase microextraction fibers for metabolic profiling of bacteria. For the first time, comprehensive metabolic profiling of both volatile and non-volatile low-molecular weight compounds in eight bacterial strains was carried out with utilization of lab-made devices. Profiles of low molecular weight metabolites were analyzed for similarities and differences using principal component analysis, hierarchical cluster analysis and random forest algorithm. The results showed clear differentiation between Gram positive (G+) and Gram negative (G−) species which were identified as distinct clusters according to their volatile metabolites. In case of non-volatile metabolites, differentiation between G+ and G− species and clustering for all eight species were observed for the chloroform fraction of the Bligh & Dyer extract, while methanolic fraction failed to recover specific ions in the profile. Furthermore, the results showed correlation between volatile and non-volatile metabolites, which suggests that lab-made devices presented in the current study might be complementary and therefore, useful for species differentiation and gaining insights into bacterial metabolic pathways.

Solid phase microextraction arrow-ion mobility spectrometry for determination of selected pesticides in water

Ion mobility spectrometry with corona discharge ion source was used for the measurements of selected pesticides cybutryne, terbutryn, dichlorvos, and quinoxyfen in water. The analyses were carried out by (i) direct injection of the aqueous solution of the pesticides and (ii) extraction using solid phase microextraction by commercial SPME arrows. The instrumental and the experimental extraction parameters including the drift tube temperature, injection port temperature, and the SPME fiber type were studied and optimized to achieve the maximum signal intensity. The limit of detections obtained by the direct injection were about 0.1–1.0 mg L−1. Using the SPME arrow-ion mobility spectrometry method, the detection limits were improved 7–50 times and obtained as 0.01, 0.015, 0.05, and 0.1 mg L−1 for terbutryn, dichlorvos, cybutryne, and quinoxyfen, respectively. The recovery rate for analysis in surface water (real samples) was approximately 90–110% for both the direct injection and solid phase microextraction method. The capability of ion mobility spectrometry for the simultaneous detection of a mixture of the studied pesticides was assessed, and it was found that terbutryn, dichlorvos, and quinoxyfen can be detected simultaneously without peak overlapping.

Urinary VOCs as biomarkers of early stage lung tumour development in mice.

Lung cancer is the primary cause of cancer-induced death. In addition to prevention and improved treatment, it has increasingly been established that early detection is critical to successful remission. The aim of this study was to identify volatile organic compounds (VOCs) in urine that could help diagnose mouse lung cancer at an early stage of its development. We analysed the VOC composition of urine in a genetically engineered lung adenocarcinoma mouse model with oncogenic EGFR doxycycline-inducible lung-specific expression. We compared the urinary VOCs of 10 cancerous mice and 10 healthy mice (controls) before and after doxycycline induction, every two weeks for 12 weeks, until full-blown carcinomas appeared. We used SPME fibres and gas chromatography- mass spectrometry to detect variations in cancer-related urinary VOCs over time. This study allowed us to identify eight diagnostic biomarkers that help discriminate early stages of cancer tumour development (i.e., before MRI imaging techniques could identify it). The analysis of mice urinary VOCs have shown that cancer can induce changes in odour profiles at an early stage of cancer development, opening a promising avenue for early diagnosis of lung cancer in other models.

Quantification of prohibited substances and endogenous corticosteroids in saliva using traditional, alternative microextraction-based, and novel 3D printed sample-preparation methods coupled with LC-MS

Oral fluid has gained significant interest as an alternative matrix for drug testing due to its easy and non-invasive collection. Despite these advantages, achieving suitably low limits of detection remains a clear challenge in the use of oral fluids for drug screening. In this study, we demonstrate that the application of commercially available SPME fibers followed by liquid chromatography tandem mass spectrometry can enable the comprehensive detection and confirmation of drugs in oral fluid samples. To this end, we develop and test a sample-preparation protocol for a panel of 46 drugs covering the most popular drugs of abuse and doping agents available worldwide. Human saliva samples were collected using a Salivette® device (CE IVD certified) and sampled using SPME devices coated with a C18 extraction phase. The proposed protocol was validated with respect to its lower limits of quantification (LLOQ), linearity, matrix effects, precision, and extraction recovery. Linearity was confirmed for all compounds (R2 > 0.97), except for testosterone (R2 = 0.953) and metandrostenolon (R2 = 0.958). Furthermore, 4 compounds suffered from matrix effects, with less than 10 % deviation from acceptance criteria. After analytical validation, saliva samples from volunteers were analyzed to determine free concentrations of cortisol at different times after awaking. Finally, a 3D-printed prototype device was designed and successfully applied to extract small molecules, thus demonstrating a new modern low-cost approach for bioanalysis.

The Characterization of Volatile Compounds of Lupin Türkiye Genotype HS-SPME/GC-MS Method

The aim of this study is to reveal the volatile and semi-volatile constituent of the local Lupinus albus L. genotype grown in Türkiye by using the HS-SPME technique. Local lupin is a legume plant with great potential due to its high seed yield and protein and oil content in the seeds. Powdered seeds of local lupin genotypes were analysed and compared with respect to types and contents of volatile semi-volatile compounds contents using four different SPME fiber with GC-MS system in W9N11, SWGDR4G4 and SWGDR4G5 libraries. Fiber with 50/30 µm DVB/CAR/PDMS identified 54 compounds, 65 µm PDMS/DVB fiber 97 compounds, 85 µm Carboxen/PDMS fiber 28 compounds, and 85 µm polyacrylate 12 compounds. As a result, 65 µm PDMS/DVB fiber is the most preferable in terms of compound identification, with 97 compound. In terms of content, Benzene, Methyl(1-Methylethyl) (39.92%), Gamma-Terpinene (12.26%), Cis-Ocimene (5.93%), 1,3,6-Octatriene,3,7-Dimethyl-(% 5.51), Beta-Myrcene (4.70%), Alpha-Pinene (4.39%), Alpha.-Thujene (4.21%), Alpha Terpinene (2.55%), Camphene (2.23%), 1,6-Octadien-3-Ol,3,7-Dimethyl (2.10%) were mostly detected in the analysis with 50/30 µm DVB/CAR/PDMS fiber. With the other fiber 65 µm PDMS/DVB; phospine oxide, triphenyl- (15.49 %), pulegone (5.03 %), L-linalool (3.85 %), cyclopentasiloxane, decamethyl (3.54 %), cyclohexasiloxane, dodecamethyl (3.13 %), cyclotrisiloxane, hexamethyl (2.32 %), oxime-,methoxy-phenyl (2.08 %), 1-pentanamine,N-pentyl (1.60 %), 3,5-octadıen-2-one (1.55 %), I-menthone (1.50 %). Fiber 85 µm Carboxen/PDMS; the most four components in the content are; Benzene, 2, 4-diisocyanato-1-methyl (54.27 %), Pyrrole-3-carbonitrile, 5-formyl-2, 4 (18.41 %), 1-Butanol, 4-(1-methylethoxy) (14.67 %), pyridine,4-(1-pyrrolidinyl)- (8.13 %). With 85 µm polyacrylate fibre the most found component is 1, 2-Benzenedicarboxylic acid, diethyl ester (98.90 %). In conclusion, as far as we know this study is the first study about the volatile content of local lupin genotype of Türkiye.

Sea-urchin-like covalent organic framework as solid-phase microextraction fiber coating for sensitive detection of trace pyrethroid insecticides in water

Pyrethroid insecticides residues in water pose a critical threat to the environment from widespread production and overuse. Therefore, it is of major relevance to develop a sensitive and efficient method to detect pyrethroid insecticides in water. In this paper, a covalent organic framework (COF) with NHCO as the structural unit was synthesized using a simple condensation reaction of TTL (NH2) and TDBA (COOH). Various characterization results and density functional theory (DFT) calculations demonstrated that multiple interactions synergistically promoted the adsorption of pyrethroid insecticides on COFTDBA-TTL. Based on the excellent extraction capability of COFTDBA-TTL, efficient detection of 11 pyrethroid insecticides in water was achieved using COFTDBA-TTL-coated SPME fiber and gas chromatography-tandem mass spectrometry (GC–MS). The results showed that the extraction enhancement factors (EFs) of pyrethroid insecticides were as high as 2584–7199, and the extraction efficiencies were 3.28–446 times higher than that of commercial fiber, which reflected its high adsorption property. Meanwhile, the limits of detection (LODs) of the COFTDBA-TTL coated fiber were as low as 0.170–1.68 ng/L under the optimal conditions, and the recoveries of 11 pyrethroid insecticides in the actual water samples were 88.5–108 %. In conclusion, the SPME-GC–MS method based on COFTDBA-TTL coated fiber was simple, rapid, and efficient, and should have a promising application in trace detection of pyrethroid insecticides in the environment.

Easy determination of benzophenone and its derivatives in sunscreen samples by direct-immersion solid-phase microextraction and gas chromatography–mass spectrometry

Benzophenones (BPs) absorb different sun radiation wavelengths, making them effective UVA and UVB filters, widely used in industry. In Europe, sunscreen products contain regulated amounts (6 % w/w) of benzophenone-3 (BP-3), usually combined with other filters like octocrylene. BPs are mutagens in UV radiation, and octocrylene may degrade into BPs, making their monitoring crucial. The present manuscript proposed a novel procedure based on liquid-liquid extraction followed by direct-immersion solid-phase microextraction (LLE-DI-SPME) to isolate and determine 10 BPs in sunscreen lotions with potential results. Parameters like extraction solvent, pH, adsorption, desorption time, stirring, sating effect, and presence of organic solvents were optimized and compared with different SPME fibers, being polyacrylate (PA) fiber the most effective. Detection and quantification were performed by gas chromatography–mass-spectrometry. Analytical parameters as limits of detection were 0.05–0.10 µg kg-1, while the linear range was 0.16 up to 2000 µg kg-1. In terms of recovery, the method ranged from 83 % to 103 %; the precision of the method was good in terms of relative standard deviation (RSD) from 3.2 % to 18.7 % and without a remarkable matrix effect (–15.06–8.45 %). Despite the complexity of the samples and the difficulty posed by the DI-SPME technique, the method proved robust. The proposed method successfully detected 10 BPs in 6 different sunscreen lotions. The total presence of BPs in sunscreens ranged from 165 to 931 mg kg-1, with BP-3 detected in all samples from 4.2 to 740 mg kg-1.

Synthesis and modification of MIL-101-NH2-based metal organic frameworks for preparation of SPME fibers using sol-gel methodology

Implementation of metal-organic frameworks (MOFs) in the separation science is attractive for many researchers, nowadays. In this study, three MOFs were synthesized and employed as extractive coating fibers. The MIL-101-NH2-based coatings were implemented in immersed solid phase microextraction (ISPME) of organophosphorus pesticides (OPPs) from real-life samples. The three different kinds of fiber coatings included MIL-101-NH2 and its acyl and ethyl modified structures as particles and 3-aminopropyl triethoxysilane (APTES) sol-gel precursor as binder. Each single MOF was coated on a stainless steel substrate via sol-gel technique. The uniform and tunable pore structure, high surface area, and capability to functionalization of MIL-101-NH2, make it susceptible for isolation of a wide range of analytes from small to large molecules. Extraction performance of the synthesized fiber coatings with different functionalities was examined on some model OPPs, followed by gas chromatography-mass spectrometry (GC–MS). The highest extraction efficiency was achieved by the acyl-modified (MIL-101-NHCOCH3) fiber coating. The effects of various parameters affecting the extraction and desorption efficiency such as desorption time, desorption temperature, ionic strength, stirring rate, extraction time and temperature for the selected fiber were investigated and optimized. All the synthesized fiber coatings showed sufficient affinity while the acyl modified extractive phase was found to be very sensitive for determination of OPPs with reliable figures of merit such as acceptable linear dynamic ranges (1–1000 & 5–1000 ng.kg−1, here two linear dynamic ranges (LDR) are reported due to the variation of LDR ranges from one analyte to another), low limits of detection (0.2–1 ng.kg−1), suitable intra–day (RSD% <13%) and inter–day relative standard deviation (RSD% <15%).