Solid-phase Microextraction Fiber Research Articles

Development of ZrO2-Coated SPME Fibers for Detecting Benzotriazole Ultraviolet Filters in Water Samples

In this study, the zirconium dioxide nanoparticles (ZrO2NPs) were coated on the surface of stainless steel (SS) by cyclic voltammetry (CV) as solid phase microextraction fiber coating for detection of the benzotriazole ultraviolet filters (BUvFs) in different real water samples. The composition and images of the new SS@ZrO2NPs fiber were characterized by scanning electron microscopy (SEM). The extraction capability of SS@ZrO2NPs fiber was investigated for the enrichment and detection of benzotriazole ultraviolet filters (BUvFs) phthalate acid esters (PAEs) and polycyclic aromatic hydrocarbons (PAHs) coupled with HPLC. The fabricated SS@ZrO2NPs fiber showed excellent extraction selectivity and good extraction capability for BUvFs. Under the optimized conditions, the SS@ZrO2NPs-SPME method presented linear ranging from 0.15 to 200 µg/L with correlation coefficients of higher than 0.9982. Moreover the limits of detection (LODs) varied from 0.020 µg/L to 0.138 µg/L. Relative standard deviations (RSDs) with single fiber were below 7.78% and 8.91% for intra-day and inter-day measurements, respectively. The developed method was used to the detection of trace BUvFs in different real water samples.

Mof-derived carbon aerogel for rapid on-site extraction of chlorophenols based on drone-liquid circulation system

The rapid on-site extraction of chlorophenols (CPs) from environmental water sample is crucial for the scientific assessment of environmental risks and the implementation of control measures. However, this process presents significant technical challenges. In this study, a solid phase microextraction (SPME) device of drone-liquid circulation system was designed. The device utilized a ZIF-8/agarose derived carbon aerogel coated fiber (ZIF-8/AG-CA-F) for on-site extraction of CPs. Compared to commercial fiber, the ZIF-8/AG-CA-F demonstrated rapid and efficient capacity towards the four selected analytes due to its interconnected hollow porous structure and rich functional groups. The fiber carried by the designed on-site device was used for extracting CPs in actual river water sample. With the help of the micro-pump, the diffusion of the analytes towards the sorptive phase was promoted by accelerating the flow rate of the water sample. The combined effect of SPME fiber and the device accelerates the extraction rate, providing a new approach for rapid and efficient on-site determination of organic pollutants.

Identification of volatile biomarkers in exhaled breath by polythiophene solid phase microextraction fiber for disease diagnosis using GC–MS

The diagnosis of diseases through monitoring of volatile organic compounds (VOCs) in exhaled breath (EB) holds great potential for clinical applications. However, a standardized method for VOC analysis in EB yet to be proposed. The present study presents an untargeted method for screening and identifying potential volatile biomarkers in EB by a lab-made solid phase microextraction (SPME) fiber. A polythiophene-based SPME fiber was produced by an electrochemical method and VOC sampling was performed under dynamic and controlled conditions. Following the sampling step, the adsorbed VOCs on the SPME fiber were analyzed using gas chromatography-mass spectrometry (GC–MS). The VOCs in EB were screened by the MS detector in selected ion monitoring (SIM) mode within the mass/charge (m/z) range of 13–94 values. Potential biomarkers among all detected VOCs in each subject’s EB sample were identified through machine learning algorithms, employing a comparative analysis of distinctive retention times (RT) and peak areas between the lung cancer (LC) and control groups in two stages. In the initial stage of the study, the areas of all peaks observed in the SIM-GC–MS chromatograms of 25 LC and 51 control group subjects were integrated, and the resulting retention times and peak areas were recorded for subsequent analysis to identify potential biomarkers. A total of 1.346 distinct compounds were detected among the 76 subjects in this step, and statistical analysis using the LightGBM algorithm revealed the potential biomarkers for LC diagnosis. The PTh-SPME fibre successfully identified four novel cancer biomarkers in breath matrix: 4-heptenal, 4-methyl-1-octene, 1,2,3,4-tetrahydro-5,8-dimethyl-1-octylnaphthalene and tetrahydro-2-(2,5-undecadiynyloxy)–2H-pyran. In the second step of the study, the efficacy of the top ten selected biomarkers was evaluated in a cohort of 166 subjects, including 70 individuals with LC and 96 in the control group. The model achieved accuracy, area under the curve (AUC), and F Score values of 0.818, 0.816, and 0.817, respectively. The test model correctly predicted 27 out of 33 subjects between LC and control groups

Application of GO@ZIF-8 MOF/molecularly imprinted polymer composite for multiple monolithic fiber solid phase microextraction: Determination of illegally added amphetamines in snacks and beverages and quantitation by GC-MS

Some adulterated products are marketed to promote weight loss, increase energy or cognition, build muscle, or promote athletic and sexual performance. They may contain undisclosed or mislabeled substances. In this study, a new method for the determination of amphetamine derivatives illegally added to beverages and snacks using a GO@ZIF-8 MOF fiber combined with molecularly imprinted polymer (MIP)/solid-phase microextraction (SPME), followed by gas chromatography-mass spectrometry (GC-MS) analysis is presented. The prepared fiber is characterized by Fourier-transform infrared (FT-IR), X-ray powder diffraction (XRD), and scanning electronic microscope (SEM) techniques. Following optimization of the extraction factors, a linear range between 0.1 and 400 μg L−1 with a coefficient of determination (R2) exceeding 0.9976 was achieved for the specified compounds. Detection limits for amphetamine derivatives were found to be between 0.023 and 0.033 μg L−1. The limits of detection were found to comply with regulatory limits, indicating the sensitivity of the method for routine analysis. This method was effectively utilized to quantify amphetamine derivatives in snakes and beverages samples. The recovery rate exceeded 96.2 %, and the error under 6.7 %, demonstrating the reliability of method. No significant interference from sample matrix components was observed, demonstrating the selectivity of the method.

An advanced sensitive detection method for internal and external exposures assessment of para-phenylenediamines and their quinone derivatives based on hierarchical pore-structured nitro-microporous organic networks

para-Phenylenediamines (PPDs) and their quinone derivatives (PPD-Qs) are emerging pollutants that are associated with neurotoxicity, reproductive toxicity, and genetic toxicity, raising significant public health concerns globally. In this study, a novel hierarchical pore-structured nitro-microporous organic networks (NO2-MONs) characterized by multiple adsorption interactions and rapid mass transfer rates was synthesized. Model fitting and adsorption experiments confirmed diverse interaction mechanisms, including pore effects, hydrogen bonding, π-π stacking, and hydrophobic interactions. Utilizing these advantages, NO2-MONs-coated solid-phase microextraction fibers facilitated the effective extraction of trace PPDs and PPD-Qs. Subsequently, a highly sensitive analytical approach was developed for detecting trace amounts of PPDs and PPD-Qs using GC-MS/MS analysis. This method significantly improved upon existing techniques, addressing the low accuracy associated with current semi-quantitative methods and enhancing sensitivity by two orders of magnitude. Notably, the achieved detection limits ranged from 0.38 to 2.6 pg mL−1, with recovery rates between 75.7 % and 117.5 % (RSD ≤ 9.8 %). This proposed approach provides technical support for investigating concentration-dose-effect relationships related to the environmental presence of PPDs and PDD-Qs, facilitating the development of relevant regulatory standards.

Comparison of Different Solid-Phase Microextraction Formats Dedicated to the Analysis of Volatile Compounds-A Comprehensive Study.

The coupling of Solid-Phase Microextraction (SPME) technology with gas chromatography (GC) has a well-established and successful history. Traditionally, SPME fibers have been the most popular form thanks to their versatility and the ease with which they can be fully automated. However, alternative geometries for SPME have been developed over the years, beginning with Stir Bar Sorptive Extraction (SBSE) and later evolving into Thin-Film SPME (TF-SPME) devices. Each of these formats offers distinct advantages and disadvantages, which are explored in this study. The primary objective of this study was to comprehensively compare available forms of SPME devices, with a special focus on the advantages of TF-SPME, a novel microextraction method particularly suited for the analysis of odorants in food. The study involved analyzing a standard mixture of 11 key food odorants, representing a range of polarities, to evaluate the efficiency of TF-SPME devices in terms of the number of analytes extracted. Furthermore, four types of TF-SPME devices were compared against each other in both standard mixtures and actual food samples. The final stage of the study employed GCxGC-ToFMS analysis to showcase the potential of the most efficient HLB-TF-SPME device in the non-targeted analysis of complex samples, exemplified by unfiltered wheat beer. This analysis demonstrated the significant capability of HLB-TF-SPME in capturing and identifying a wide range of volatile compounds in complex matrices.

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.

Coupling solid phase microextraction to integrated optical sensors with microfluidic open interface

Increasing number of regulations today is very demanding, so many fields need to rely to screening techniques to separate samples whose content need to be confirmed with that field's gold standard approach. Therefore, the development of simple and fast approaches is very much needed. This manuscript presents the development of a microfluidic open interface integrated with ultraviolet-visible (UV–Vis) absorption detection for rapid screening applications. The system was designed as a rapid sensor readout for compounds enriched by solid-phase microextraction devices. Two azo dyes from a liquid water enhancer solution served as model analytes. These two dyes were extracted with the solid phase microextraction fiber and introduced to the system for analysis. Experimental results demonstrated that the system could effectively detect dyes with absorbance at 403 nm, indicating its potential for quantitating analytes with UV–Vis chromophores. Although this sensing method exhibits limited selectivity, it offers a cost-effective, straightforward approach to rapid screening that can be conveniently miniaturized for on-site applications. Further advances could focus on integrating low-cost sensors with specific responses in place of the UV–Vis unit, as well as simplification and miniaturization of the system to improve on-site analysis. Additionally, incorporating autosampler systems could enable high-throughput determinations, broadening the method's applicability. The developed solid phase microextraction method reliably samples and enriches small molecules from complex systems, delivering clean extracts to the selective sensor for readout without interference from the investigated sample matrix.

Assessment of greenness for solid phase microextraction techniques of sample preparation for flavors by AGREE Prep & SPMS tools

Assessing the greenness of sample preparation techniques is essential due to the use of various solvents, chemicals, reagents, sorbents, pH adjustments, and energetic inputs. Solid-Phase Microextraction (SPME) is preferred over traditional flavor extraction methods such as Simultaneous Distillation Extraction (SDE) and Solvent-Assisted Flavor Evaporation (SAFE) because of its sensitivity, efficiency, speed, versatility, and economy. SPME fibers coated with stationary phases can extract volatile and semi-volatile flavor compounds from food samples, which are then desorbed and analyzed by Gas Chromatography-Mass Spectrometry (GC–MS). This article provides an assessment of the greenness of 50 SPME techniques for flavor analysis using the AGREE Prep and Sample Preparation Metric of Sustainability (SPMS) tools. This evaluation offers valuable insights into the environmental impact and sustainability of SPME as sample preparation techniques for flavour analysis. As per AGREE Prep, method 34 was found to be environmental friendly with score of 0.66, attributed to safe solvents, minimized waste, high sample throughput, and low energy consumption where as method 7 with SPMS scores of 7.05 is more sustainable due to miniaturization, fewer steps, and low energy use.

Recovery and detection of ignitable liquid residues from the substrates by solid phase microextraction – direct analysis in real time mass spectrometry

In this study, direct analysis in real time mass spectrometry (DART-MS) was coupled to the solid phase microextraction (SPME) to extract and analyze the ignitable liquid residues (ILR) present in the sample matrices. The SPME extraction parameters, such as extraction temperature and extraction time, were optimized using a two-factor central composite design. The SPME-DART-MS setup was utilized to analyze the substrates and fire debris matrices spiked with gasoline. The results indicate that the less volatile marker compounds from gasoline were recovered from the substrates and fire debris, and their profiles matched well with the gasoline liquid samples analyzed directly by DART-MS. As expected, the effective extraction of marker compounds in gasoline required a relatively high temperature, i.e., 150 ℃. In the presence of a matrix, a higher extraction temperature and longer extraction time could benefit the extraction efficiency. The desorption of ILR on SPME fiber was performed by inserting the fiber into the DART-MS helium gas stream at 300 ℃ for 1 min with no carry-over residues being observed between successive samples. The chemical information attained with this method is typically not observed in the current GC/MS-based practice. The SPME-DART-MS was also extended to reanalyze less volatile components of ILR on substrates after the ASTM E1412 activated charcoal method, which indicates its possible application subsequent to the traditional GC/MS ILR analysis. The SPME-DART-MS has shown promise in ILR detection as an important complementary tool.

Portable Miniature Mass Spectrometry for Enhanced On-Site Detection of Analytes in Complex Samples by Integrating Solid-Phase Microextraction and Nano-Electrospray Ionization.

On-site mass spectrometry (MS) analysis plays a crucial role in timely understanding chemical compositions of field samples but presents a challenge to miniaturization, portability, and sensitivity. In this work, a portable MS approach was developed by integrating biocompatible solid-phase microextraction (SPME) and a nano-electrospray ionization (nESI) emitter into a kit to couple miniature MS (mMS). The SPME fiber was used for on-site extractive sampling of analytes from complex liquid samples and living organisms and was then inserted into an nESI emitter for on-site MS analysis via the facile kit. The limit of detection was found to be at the pg/mL level for various compounds tested. Acceptable relative standard deviation (RSD) values (5.5-7.6%, n = 6) were obtained for direct measurement of analytes in complex matrixes; acceptable linear responses (0.1-50 ng/mL) and matrix effects (76.0-82.6%) were also found. Enhanced detection of compounds of interest in various real samples, such as food samples, human fluids, environmental water, and living organisms, was unambiguously demonstrated. Our experimental data showed that SPME-nESI-mMS is a promising tool for on-site analysis of various complex samples in significant applications including but not limited to food safety, environmental monitoring, forensic investigation, and bioanalysis.

SPME arrow-based extraction for enhanced targeted and untargeted urinary volatilomics

BackgroundVolatile organic compounds (VOCs) present in human urine are promising biomarkers for various health conditions and environmental exposures. However, their reliable detection is challenging due to the complexity of urinary matrices and the low concentrations of VOCs. Moreover, untargeted approaches present considerable challenges in terms of data interpretation, increasing the complexity of method development. Here we address these challenges by developing a new method that combines solid-phase microextraction (SPME) Arrow with gas chromatography-high resolution mass spectrometry (GC-HRMS), using a design of experiments (DOE) approach for targeted and untargeted compounds. This methodology, specifically tailored for SPME Arrow, represents a significant advancement in untargeted urinary analysis. ResultsThe method was developed based on targeted and untargeted outcomes, were ranking results focus on the highest response area of 11 spiked target VOCs representative of urinary volatilomics, and on identifying the maximum untargeted number of VOCs. The method was developed focusing on the highest response area of 11 spiked target VOCs representative of urinary volatilomics and identifying the maximum number of VOCs. A univariate method determined the optimal coating type, urine volume, and salt addition. Subsequently, a central composite design (CCD) DOE was used to determine ideal temperature, extraction, and incubation times. The best method obtained has an extraction time of 60 min at a temperature of 53 °C, with an SPME Arrow CAR/PDMS using 2 mL of urine, with 0.25 % w/v of NaCl and a pH of 2. Compared to conventional SPME fibers, the SPME Arrow showed improved extraction efficiency, detecting more VOCs. Finally, the enhanced method was successfully applied to urine samples from children exposed and non-exposed to tobacco smoke, identifying specific VOCs, like p-cymene and p-isopropenyl toluene related to tobacco exposure. SignificanceBy integrating both targeted and untargeted approaches, the developed method comprehensively captures the complexity of urinary metabolomics. This dual strategy ensures the precise identification of known compounds and the discovery of novel biomarkers, thereby providing a more complete metabolic profile. Such an approach is crucial for advancing in non-invasive diagnostics and environmental health studies, as it offers deeper insights into the intricate relationships between metabolic processes and various health conditions.

Advancing Lung Cancer Diagnosis through NH2-MON-SPME-GC-MS/MS: Enhanced Sensitivity in Aldehyde Biomarker Detection from Exhaled Breath.

The sensitive detection of trace biomarkers in exhaled breath for lung cancer diagnosis represents a critical area of research in life analytical chemistry, with profound implications for early disease detection, therapeutic intervention, and prognosis monitoring. Despite its potential, the analytical process faces significant challenges due to the ultratrace levels of disease biomarkers present and the complex, high-humidity composition of exhaled breath. This study introduces a highly sensitive method for detecting aldehyde biomarkers in exhaled breath by integrating the use of amino-functionalized microporous organic networks (NH2-MON) as a solid-phase microextraction (SPME) fiber coating with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) analysis. The method innovatively combines sample collection and extraction, achieving a dual-step enrichment process that significantly enhances both the enrichment efficiency and reproducibility of biomarker detection while effectively mitigating the interference caused by water vapor in exhaled breath. The NH2-MON, utilized as an SPME fiber coating, demonstrates exceptional enrichment capacity for five key aldehyde biomarkers, facilitating the development of a highly sensitive detection approach for these biomarkers in exhaled breath. Compared to previously reported methods, the proposed technique exhibits significantly lower limits of quantification, ranging from 0.77 to 11.89 pg mL-1, and achieves substantially higher enrichment factors, ranging from 9156- to 35723-fold. The practicality and feasibility of the method were validated through the analysis of exhaled breath samples from lung cancer patients, underscoring its potential application in the early diagnosis and monitoring of lung cancer.

Detection and health implications of phthalates in tea beverages in market: Application of novel solid-phase microextraction fibers

Assessment and control of emerging organic pollutants in food have become critical for global food safety and health. The European Union has set standards for certain emerging organic pollutants, such as phthalic acid esters (PAEs) in food. Because of being endocrine disruptors, PAEs are toxic and carcinogenic to humans. Release of PAEs from packaging materials poses a potential risk to human health and causes environmental pollution. In this study, a highly sensitive analytical method for the detection of PAE contents in tea beverages was established using hydroxyl-functionalized covalent organic frameworks (COFs) as solid-phase microextraction (SPME) coating. Results indicate that functionalization with hydroxyl groups enhances the adsorption of PAEs. The proposed method exhibits a wide linear range (1–20,000 ng L−1), low limits of detection (> 0.048 ng L−1), and satisfactory recovery (72.8 %–127.3 %). To investigate the PAE contamination in beverages, contamination levels of six typical PAEs and their health impacts were surveyed across various brands/types/packaging materials of tea beverages sold in China. Results of the hazard quotient and hazard index approaches suggest no or extremely low health concerns regarding PAE levels. We observe that hydroxyl groups functionalized on COFs enhance the adsorption of PAEs. Moreover, an important outcome of this study is development of an efficient and sensitive direct detection method for PAEs in complex tea matrices, providing a reliable approach for the assessment of PAEs in other complex matrices.

Application of new green evaluation tools to assess the environmental impact of analytical procedures based on solid phase microextraction techniques

In this comparative study, four green evaluation tools, blue applicability grade index (BAGI), Analytical GREEnness (AGREE), Green Analytical Procedure Index (GAPI), and Analytical Eco-Scale were evaluated to assess 16 selected analytical methods including fiber-solid phase microextraction, stir bar sorptive extraction, and thin film microextraction joint to gas and liquid chromatographic as well as spectrofluorimetry techniques. The required parameters and data were extracted from the selected articles and calculations were performed based on the unique evaluation protocol of each tool. A uniform approach was applied in calculations and evaluations. A comparison of selected methods was done by determining the factors affecting greenness. High energy consumption, organic solvents, waste generation, analysis throughput, and the number of determined analytes, are among the crucial parameters that require improvement in the selected methods. The results show that using more than one evaluation tool in evaluating the greenness of analytical methods is very effective in obtaining synergistic results and increasing the understanding of the greenness of analytical methods.

High-performance solid-phase microextraction based on a nanocomposite sorbent of MOF/COF hybrid for ultra-trace analysis of trifluralin in food samples using the ion mobility spectrometer

Two well-known porous hybrid materials, a metal-organic framework (MOF) based on manganese and a melamine-rich covalent organic framework (COF) were combined, resulting in a highly effective nanocomposite sorbent of Mn-terephthalic acid (TA) /COF. After investigating the properties of the synthesized adsorbent, it was finally used as a new fiber for solid-phase microextraction. The method, named high-performance solid-phase microextraction (HPSPME), was utilized for the extraction and ultra-trace analysis of trifluralin in agricultural waters, fruit, and vegetable samples by using corona discharge ionization-ion mobility spectrometer (CD-IMS). To increase the extraction efficiency, experimental parameters including, temperature and time of extraction and desorption, solution pH, and stirring rate were optimized. Considering the optimized conditions, the enrichment factor of 2002, the limit of detection (LOD) 0.08 ng mL−1 (S/N=3), and linear dynamic range (LDR) 0.25–10.00 ng mL−1 with a coefficient of determination (R2=0.9987) were obtained. Relative standard deviations (RSDs, n = 3) of <9.7, <3.5, and <8.9 % were obtained, respectively, for reproducibility of the prepared fibers, intra- and inter-day. The relative recovery values for the real samples were 84–124 %. The proposed method’s accuracy for the sample impregnated with trifluralin was also evaluated by the EPA standard method.

The impact of sampling time point on the lipidome composition

Lipidomic profiling has been reported as an effective approach for characterizing and differentiating brain tumors. However, since lipids can undergo non-specific enzymatic and nonenzymatic reactions due to tissue disruption, it is critical to consider the preanalytical phase of the diagnostic process (e.g., optimizing the sampling time and sampling conditions). Thus, this study assesses the ways in which the time point of sampling impacts the lipidome composition of brain tumors. Two histologically distinct brain tumors—namely, meningiomas and gliomas—were sampled using solid-phase microextraction (SPME) fibers at two time points: on-site directly after removal, and after 12 months of storage at −30 °C. The samples were analyzed via HILIC chromatography coupled with HRMS, which enabled the detection of a wide range of features, including phospholipids and sphingolipids, as well as changes in the profiles of these compounds. The samples obtained from the stored tissues tended to have elevated levels of analytes with lower m/z values. In addition, the samples obtained from the fresh and stored tissues were easily distinguished based on their lipidome compositions, regardless of the histological tumor type. Notably, while storage did not affect the possibility of differentiating meningiomas and gliomas, the biological interpretation of the obtained results were prone to bias.

Determination of volatile organic compounds (VOCs) in indoor work environments by solid phase microextraction-gas chromatography-mass spectrometry

Volatile organic compounds (VOCs) are continuously emitted into the atmosphere from natural and anthropogenic sources and rapidly spread from the atmosphere to different environments. A large group of VOCs has been included in the class of air pollutants; therefore, their determination and monitoring using reliable and sensitive analytical methods represents a key aspect of health risk assessment. In this work, an untargeted approach is proposed for the evaluation of the exposure to volatile organic compounds of workers in an engine manufacturing plant by GC–MS measurements, coupled with solid-phase microextraction (SPME). The analytical procedure was optimized in terms of SPME fiber, adsorption time, desorption time, and temperature gradient of the chromatographic run. For the microextraction of VOCs, the SPME fibers were exposed to the air in two different zones of the manufacturing factory, i.e., in the mixing painting chamber and the engine painting area. Moreover, the sampling was carried out with the painting system active and running (system on) and with the painting system switched off (system off). Overall, 212 compounds were identified, but only 17 were always present in both zones (mixing painting chamber and engine painting area), regardless of system conditions (on or off). Finally, a semi-quantitative evaluation was performed considering the peak area value of the potentially most toxic compounds by multivariate data analyses.

Preserving the Aromatic Profile of Aged Toma Piemontese PDO Cheese with Gaseous Ozone Technology: A Quality Assessment via SPME-GC–MS/E-Nose

The efficacy of low gaseous ozone concentrations (300 ppb and 400 ppb) in controlling spoilage microflora and preserving the quality of the aged Toma Piemontese PDO cheese was explored. The research integrates consumer tests, Gas Chromatography-Mass Spectrometry (GC-MS) with Solid phase Microextraction (SPME) fiber and Electronic Nose (e-nose) analysis to conduct a detailed assessment of the cheese's aromatic composition. Results indicate that low ozone concentrations significantly affected spoilage microflora, preserving the overall quality. Through GC-FID (Flame Ionization Detection) analysis, 22 of all identified compounds by GC-MS were quantified, including ethyl acetate (sweety), diacetyl and acetoin (buttery). Compared with the untreated sample, ozone treatments maintained the distinctive characteristics of Toma Piemontese PDO cheese, reducing the formation of off-flavors-related compounds (i.e., ethanol). Moreover, ozone-treated samples correlated with positive aroma scores given by consumers. However, sensory perception involves complex interactions among aroma compounds, highlighting the importance of advanced approaches. The utilization of a 12-sensor Quartz Microbalance (QMB) e-nose played a crucial role in identifying subtle differences in aroma, contributing to a more nuanced understanding of ozone treatments on the cheese's sensory profile. In conclusion, this research demonstrates the potential of ozone technology as a viable and effective method for improving the quality of aged Toma Piemontese PDO cheese.

Engineering of dual recognition functional aptamer-molecularly imprinted polymeric solid-phase microextraction for detecting of 17β-estradiol in meat samples

In this study, an enhanced selective recognition strategy was employed to construct a novel solid-phase microextraction fiber coating for the detection of 17β-estradiol, characterized by the combination of aptamer biorecognition and molecularly imprinted polymer recognition. Benefiting from the combination of molecularly imprinted and aptamer, aptamer-molecularly imprinted (Apt-MIP) fiber coating had synergistic recognition effect. The effects of pH, ion concentration, extraction time, desorption time and desorption solvent on the adsorption capacity of Apt-MIP were investigated. The adsorption of 17β-estradiol on Apt-MIP followed pseudo-second order kinetic model, and the Freundlich isotherm. The process was exothermic and thermodynamically spontaneous. Compared with polymers that only rely on imprinted recognition, non-imprinted recognition or aptamer affinity, Apt-MIP had the best recognition performance, which was 1.30–2.20 times that of these three materials. Furthermore, the adsorption capacity of Apt-MIP for 17β-estradiol was 885.36–1487.52 times than that of polyacrylate and polydimethylsiloxane/divinylbenzone commercial fiber coatings. Apt-MIP fiber coating had good stability and could be reused for more than 15 times. Apt-MIP solid-phase microextraction coupled with high-performance liquid chromatography was successfully applied to the determination of 17β-estradiol in pork, chicken, fish and shrimp samples, with satisfactory recoveries of 79.61 %–105.70 % and low limits of detection (0.03 μg/kg). This work provides new perspectives and strategies for sample pretreatment techniques based on molecular imprinting technology and improves analytical performance.