A new sustainable filtration membrane extraction method based on nanoconfined liquid phase extraction: Determination of organochlorinated pesticides and pyrethroids in tea samples.

BACKGROUND: Pesticides are used in agricultural production for prevent and control crop diseases and pests, but it is easy to cause excessive pesticides residues in agricultural products, polluting the environment and endangering human health. Due to their unmatched and sustainable capabilities, nanoextraction procedures are becoming every day more important in Analytical Chemistry. In particular, nanoconfined liquid phase extraction has shown extraction capabilities toward polar, medium polar, and/or nonpolar substances, which can be easily modulated depending on the nanoconfined solvent used. Furthermore, this "green" technique showed excellent characteristics in terms of recoveries, extraction time (≤1 min), reliability, and versatility. (97) RESULTS: In this work, the advantages of this technique have been coupled with those of filtration membrane extraction, making use of carbon nanofibers (CnFs) growth on carbon microspheres (CµS). This substrate has been deposited on a filter, which combined with gas chromatographic mass spectrometry (GC-MS) analysis successfully employed for the nanoextraction of 30 pesticides (18 organochlorine and 12 pyrethroids) in tea samples. Under the optimized extraction conditions, the linear range with standard solutions was from 1 to 1000 ng mL-1 (R2 ≥ 0.99), the limit of detections in tea samples were in the range 0.56-17.98 µg kg-1. The accuracy of the developed method was evaluated by measuring the extraction recovery of the spiked tea samples, and recoveries between 74.41 % and 115.46 %. (119) SIGNIFICANCE: Considering the versatility of nanoconfined liquid phase extraction and the functionality of the filtration membrane extraction procedure, this new extraction method can be considered a powerful candidate for automatized high-throughput analyses of real samples. (34).

Development of a highly sensitive method based on QuEChERS and GC-MS/MS for the determination of polycyclic aromatic hydrocarbons in infant foods.

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants that can be found in various food products, including those intended for infants. Due to their potential health risks, it is crucial to develop sensitive analytical methods for the accurate determination of PAHs in infant foods. This study describes the development and validation of a highly sensitive method for the quantification of European PAH markers, namely benzo[a]pyrene, benzo[a]anthracene, chrysene, and benzo[b]fluoranthene, using gas chromatography-tandem mass spectrometry (GC-MS/MS), in baby food samples. The first step was the optimization of the sample preparation procedure, performed using different methods based on the QuEChERS approach, also testing different extraction solvents. Several factors such as extraction efficiency, selectivity, and recovery were evaluated to choose the most effective procedure for sample preparation. Furthermore, the GC-MS/MS method was optimized, evaluating parameters such as linearity, sensitivity, accuracy, and robustness using spiked infant food samples. The method demonstrated excellent linearities with a correlation coefficient higher than 0.999 over a wide concentration range, and limits of detection and limits of quantification in the range 0.019-0.036 µg/kg and 0.06-0.11 µg/kg, respectively. Extraction recoveries were between 73.1 and 110.7%, with relative standard deviations always lower than 8%. These findings are compliant with the indications of the European Commission (Reg. 836/2011). To assess the applicability of the method to official control activities, a survey was conducted on commercially available infant food products. Four markers were determined in commercial samples belonging to different food categories for infants and young children. The outcome of this monitoring showed that PAH contamination, in all samples, was below the quantification limits. In conclusion, the developed GC-MS/MS method provides a highly sensitive and reliable approach for the determination of PAHs in baby foods. The optimized sample preparation, instrumental parameters, and validation results ensure accurate quantification of 4 PAHs even at trace levels. This method could contribute to the assessment of PAH exposure in infants and it could support regulatory efforts to ensure the safety and quality of infant food products with regular monitoring.

How new nanotechnologies are changing the opioid analysis scenery? A comparison with classical analytical methods.

Opioids such as heroin, fentanyl, raw opium, and morphine have become a serious threat to the world population in the recent past, due to their increasing use and abuse. The detection of these drugs in biological samples is usually carried out by spectroscopic and/or chromatographic techniques, but the need for quick, sensitive, selective, and low-cost new analytical tools has pushed the development of new methods based on selective nanosensors, able to meet these requirements. Modern sensors, which utilize "next-generation" technologies like nanotechnology, have revolutionized drug detection methods, due to easiness of use, their low cost, and their high sensitivity and reliability, allowing the detection of opioids at trace levels in raw, pharmaceutical, and biological samples (e.g. blood, urine, saliva, and other biological fluids). The peculiar characteristics of these sensors not only have allowed on-site analyses (in the field, at the crime scene, etc.) but also they are nowadays replacing the gold standard analytical methods in the laboratory, even if a proper method validation is still required. This paper reviews advances in the field of nanotechnology and nanosensors for the detection of commonly abused opioids both prescribed (i.e. codeine and morphine) and illegal narcotics (i.e. heroin and fentanyl analogues).

Multipurpose new gas chromatography column based on pillararenes functionalized with imidazolium ionic liquids.

BACKGROUND: Gas chromatography is worldwide recognized as one of the most important analytical techniques, due to its high versatility and reliability. The heart of a gas chromatograph is the column, that allows analyte peak separations and, consequently, accurate qualitative and qualitative analyses. New and more efficient columns are always requested to satisfy new and challenging analytical needs. RESULTS: In this work, imidazolium ionic liquids functionalized pillar [5] arenes have been used for the first time as gas chromatographic stationary phases, considering their highly symmetric pillar-shaped architecture with cavities rich in π-electrons. Four imidazolium ionic liquids functionalized pillar [5] arenes have been tested as stationary phases with numerous analytes and isomers. In particular, one of these showed superior performances if compared to commercial columns, enabling challenging isomeric separations of halogenated benzenes, aromatic aldehydes, and aromatic anilines. SIGNIFICANCE AND NOVELTY: To our knowledge, this is the first report on the use of the ionic liquid P[n]A as a stationary phase in chromatography, either in GC or liquid chromatography (LC) separations. This work demonstrates the promising potential of ionic liquid P[n]A stationary phases for chromatographic separations.

Microextraction of essential oils: A review.

Liquid phase microextraction (LPME) and solid phase microextraction (SPME) are popular extraction techniques for sample preparation due to their green and highly efficient single-step extraction efficiency. With the increasing attention to essential oils, their evaluation and analysis are significant in analytical sciences. In this review, starting from a brief description of the recent advances in the last decade, the attention has been focused on the up-to-date research works and applications based on liquid and solid phase microextraction for essential oil analyses. Particular attention has been given to the approaches using ionic liquids, eutectic solvents, gas flow assisted, and novel composite materials. In the end, the technological convergence of novel microextraction of essential oils in the future has been prospected.

Efficient gas chromatographic separation of xylene and other aromatic isomers by using pillar[6]arene-based stationary phase.

The separation of aromatic isomers, in particular xylene isomers, represents a big issue in chemical and petroleum industries, owing to their similar molecular sizes and boiling points. In this work, the investigation ofpillar[6]arene derivative modified by long alkyl chains (P6A-C10) as a stationary phase for high-resolution gas chromatographic (GC) separations of xylene isomers is presented. Pillar[n]arenes are a new class of macrocyclic hosts that can accommodate specific guests due to their highly symmetrical and rigid pillar architectures with π-electron rich cavities. The P6A-C10 column showed high-resolution performance towards xylene isomers, with peculiar advantages if compared with the commercial HP-5, HP-35, DB-17, and PEG-20Mcolumns.A quantum chemistry calculation has been performed, showing a difference in non-covalent interactions with the P6A-C10 pillar framework, which leads to specific selectivity for xylene isomers.Furthermore, the P6A-C10 column exhibited good repeatability.

Is pomegranate husk scald during storage induced by water loss and mediated by ABA signaling?

BACKGROUND: Husk scald (HS) is a physiological disorder limiting the marketability of pomegranate fruit during long-term storage. Herein we propose that HS is triggered by water loss and mediated by ABA signaling. Therefore, pomegranate fruit were stored at three different storage temperatures (3.5, 7 and 11°C) and 96.5% ± 2.3% relative humidity (RH) evaluating weight loss (WL), abscisic acid (ABA), respiration rate (RR), total phenolics (TP), total anthocyanin (TA), antioxidant activity (AA), exocarp electrolyte leakage (EL), malondialdehyde (MDA), color attributes, browning index and visual quality of fruit. RESULTS: HS appeared after 3 months of storage at 11 °C, less at 7°C and non-present at 3.5°C. Incidence of HS occurred along with higher WL, RR, EL, MDA, and ABA content. Conversely, TP, TA and AA decreased significantly. WL increased with water vapor pressure deficit (VPD) at higher temperatures. After 93 days, 11 °C fruit reached ~10% WL while ABA increased to ~150 µg kg-1 . However, 3.5 and 7 °C fruit, reached 5 and 7% WL while ABA was ~31 and 75 µg kg-1 , respectively. CONCLUSION: Herein, we propose a mechanistic model of HS development where water stress induces ABA as a primary signaling molecule that triggers the HS response mediated by reactive oxygen species (ROS). Accumulation of ROS induces phenolic biosynthesis and oxidative stress promotes loss of membrane compartmentalization that induces phenolic degradation. Ultimately, husk scalding becomes visible due to the oxidation of phenolics into brown pigments. © 2022 Society of Chemical Industry.

Chromatographic Separation of Aromatic Amine Isomers: A Solved Issue by a New Amphiphilic Pillar[6]arene Stationary Phase.

In this work, the fabrication, synthesis, and characterization of a new stationary phase based on an amphiphilic pillar[6]arene (P6A-C10-2NH2) for gas chromatographic analyses are reported. The gas chromatography (GC) column prepared with P6A-C10-2NH2 stationary phase exhibited a medium polarity, an efficiency of 3219 plates/m, and unmatched resolving capabilities toward chloroaniline, bromoaniline, iodoaniline, and toluidine isomers. Furthermore, the P6A-C10-2NH2 column showed excellent repeatability with maximum relative standard deviations equal to 0.02, 0.07, and 2.56% for run-to-run, day-to-day, and column-to-column, respectively, demonstrating a great potential as a new stationary phase in separation science.

Fast removal of phenolic compounds from water using hierarchical porous carbon nanofibers membrane.

Water pollution is becoming increasingly serious and seriously endangering human health, especially the direct emissions of phenolic compounds. An integrated sample pre-treatment and derivatization method based on a biopolymers/TEOS-based carbon nanofibers microextraction that allows rapid extraction (5 min), followed by separation and highly sensitive detection of phenolic compounds by gas chromatography‒mass spectrometry (GC-MS) analysis, is described. The developed methodology, coupled with GC-MS, allowed low detection limits (0.03-0.32 ng mL‒1), good linearities (0.5-200 ng mL‒1) and recoveries (73.58-85.76%) to be achieved in a few steps and short time. Based on the high adsorption properties of materials, the on-line removal device of phenolic compounds in water was designed. The elimination rate of phenolic compounds in water was higher than 73.58% at 1 mL min‒1 and three cycles. The elimination strategy for the phenolic compounds is very versatile and is easy to apply.

A New Capillary Gas Chromatography Column Based on Poly(ethylene glycol) Methyl Ether-Functionalized Calix[4]arene.

In this work, a novel capillary column (C4A-mPEG) with a calixarene-based polymer stationary phase (poly(ethylene glycol) methyl ether-functionalized 4-tert-butylcalix[4]arene) was designed and used for gas chromatographic (GC) separations. The C4A-mPEG capillary column, prepared by the static coating method, showed moderate polarity and a column efficiency of 2332 plates/m, determined by 1-octanol at 120 °C. The separation features of C4A-mPEG stationary phase, resulting from its unique structure and multiple molecular recognition processes with analytes, including π-π, H-bonding, dipole-dipole, and van der Waals interactions, allowed to obtain high-resolution performances for a wide range of compounds and their isomers, especially benzaldehydes, phenols, and anilines. Moreover, compared with 4-tertbutyl calix[4]arene (C4A) and polyethylene glycol (PEG) stationary phases, a higher resolving capability was also observed for the separation of toluidine and xylidine isomers.

High-Resolution Micro-object Separation by Rotating Magnetic Chromatography.

The development of new technologies for the separation, selection, and isolation of microparticles such as rare target cells, circulating tumor cells, cancer stem cells, and immune cells has become increasingly important in the last few years. Microparticle separation technologies are usually applied to the analysis of disease-associated cells, but these procedures often face a cell separation problem that is often insufficient for single specific cell analyses. To overcome these limitations, a highly accurate size-based microparticle separation technique, herein called "rotating magnetic chromatography", is proposed in this work. Magnetic nanoparticles, placed in a microfluidic separation channel, are forced to move in well-defined trajectories by an external magnetic field, colliding with microparticles that are in this way separated on the basis of their dimensions with high accuracy and reproducibility. The method was optimized by using fluorescein isothiocyanate-modified polystyrene particles (chosen as a reference standard) and then applied to the analysis of cancer cells like Hep-3B and SK-Hep-1, allowing their fast and high-resolution chromatographic separation as a function of their dimensions. Due to its unmatched sub-micrometer cell separation capabilities, RMC can be considered a break-through technique that can unlock new perspectives in different scientific fields, that is, in medical oncology.

Circular Nonuniform Electric Field Gel Electrophoresis for the Separation and Concentration of Nanoparticles.

A circular nonuniform electric field strategy coupled with gel electrophoresis was proposed to control the precise separation and efficient concentration of nano- and microparticles. The circular nonuniform electric field has the feature of exponential increase in the electric field intensity along the radius, working with three functional zones of migration, acceleration, and concentration. The distribution form of electric field lines is regulated in functional zones to control the migration behaviors of particles for separation and concentration by altering the relative position of the ring electrode (outside) and rodlike electrode (inner). The circular nonuniform electric field promotes the target-type and high-precision separation of nanoparticles based on the difference in charge-to-size ratio. The concentration multiple of nanoparticles is also controlled randomly with the alternation of radius, taking advantage of vertical extrusion and concentric converging of the migration path. This work provides a brand new insight into the simultaneous separation and concentration of particles and is promising for developing a versatile tool for the separation and preparation of various samples instead of conventional methods.

On the use of a 2D-carbon microfiber fractionation system to improve flow-injection QTOF-HRMS analysis in complex matrices: the case of Abelmoschus manihot flower extracts.

A two-dimensional microscale carbon fiber/active carbon fiber system combined with a quadrupole time of flight high-resolution mass spectrometry (2DµCFs-QTOF-HRMS) system is proposed for the rapid putative identification of polar, medium-polar and weakly polar constituents in complex matrices while strongly mitigating ionic suppression effects. The capabilities of 2DµCFs-QTOF-HRMS have been proven by analysing the composition of Abelmoschus manihot flower extracts, allowing, in a single run, the detection of 41 known substances and the presence of 6 compounds never revealed before in these samples. 2DµCFs-QTOF-HRMS has been compared with traditional HPLC-MS, showing higher versatility and a significant reduction of both analysis time (70 min to 5 min) and solvent consumption (35 mL to 1.5 mL). A comparison with the results obtained by direct flow-injection MS analyses demonstrated that 2DµCFs-QTOF-HRMS leads to a more comprehensive analysis and to improved detection sensitivity. The proposed method can be considered suitable for the rapid and comprehensive analysis of food, environmental and pharmaceutical complex samples. 2DµCFs-QTOF-HRMS can thus be considered a rapid, versatile, reliable, high-throughput and economical technique that allows for the collection of information on polar, semipolar, and weakly polar components in complex matrices.

Tracing historical changes, degradation, and original sources of airborne polycyclic aromatic hydrocarbons (PAHs) in Jilin Province, China, by Abies holophylla and Pinus tabuliformis needle leaves.

Due to their wide distribution and availability, plant leaves can be considered interesting candidates as biomonitoring substrates for the evaluation of atmospheric pollution. In addition, some species can also retain historical information, for example, related to environmental pollution, due to their leaf class age. In this study, the content of polycyclic aromatic hydrocarbons (PAHs) in Abies holophylla and Pinus tabuliformis needle samples in the function of their class age has been investigated to obtain information regarding the degradation constant for each PAH under investigation (α values ranging from 0.173 to 1.870) and to evaluate the possibility to correlate the presence of PAHs in needles with some important pollution environmental factors. Considering air pollutant variables registered in Jilin Province, interesting correlations (at 95% confidence level) have been found between coal consumption per year and anthracene contents in needles, while fluorene, phenanthrene, and anthracene results correlated with coal consumption. Furthermore, it has been demonstrated that the total PAH concentration in needles, for both species, increased with their age (from 804 to 3604 ng g-1 dry weight), showing a general tendency to accumulate these substances through years. PAH degradation rates increased instead with molecular complexity. This study could be considered a first trial to obtain historical environmental information by pine needles biomonitoring.

Ex-situ and in-situ rapid and quantitative determination of benzene derivatives in seawater using nanoconfined liquid phase nanoextraction.

Benzene derivatives (BDs) constitute a class of environmental pollutants whose exposure poses a grave risk to human health. These compounds rapidly diffuse from the atmosphere to the marine ecosystem: for this reason, their monitoring in seawater is every day more compelling. In this work, nanoconfined liquid phase nanoextraction (NLPNE), a versatile extraction technique recently described, has been for the first time applied to the gas chromatographic mass spectrometry (GC/MS) analysis of BDs in seawater. Ex-situ and in-situ NLPNE procedures have been developed and optimized in terms of extraction capabilities, analysis time, precision, and accuracy. Compared to the traditional extraction procedures, based on solid-phase microextraction (SPME) and liquid-liquid extraction (LLE), the proposed NLPNE methods allowed a rapid on-site analysis of benzene compounds with low solvent consumption, higher enrichment factors, and improved automation grade. Determination coefficients ranging from 0.9929 to 0.9997 were obtained for all BDs in the range 0.10-500 ng mL-1 and 5.00-500 ng mL-1, for ex-situ and in-situ NLPNE, respectively. Ex-situ and in-situ limits of detection ranged from 0.2 to 7.6 ng mL-1 and 0.04-1.00 ng mL-1. Our results suggest that NLPNE coupled to GC-MS can be considered a powerful technique for high-throughput analyses of trace compounds in environmental, food and biological samples.

Nanoconfined Liquid Phase Nanoextraction Based on Carbon Nanofibers.

An innovative and versatile microextraction technique based on nanoconfined solvent on carbon nanofibers has been conceived, realized, optimized, and presented here. The extraction capabilities of this technique toward polar, medium polar, and/or nonpolar substances can be easily modulated based on the nanoconfined solvent used. The so-called nanoconfined liquid phase nanoextraction showed excellent characteristics in terms of extraction recoveries, extraction time (≤1 min), reliability, and versatility. A needle-tip device has been realized on the base of this extraction process to allow direct extraction procedures and minimally invasive testing: this device guarantees a safe insertion in aqueous or soft samples, and it allows a fast and minimally invasive analyte extraction. Due to its versatility, chemical stability, and mechanical flexibility, nanoconfined liquid phase nanoextraction can be considered a powerful candidate for high-throughput analyses of biological samples.

Development, Optimization, and Comparison of Different Sample Pre-Treatments for Simultaneous Determination of Vitamin E and Vitamin K in Vegetables.

The absence of vitamin E from the diet can lead to cardiovascular disease, cancer, cataracts, and premature aging. Vitamin K deficiency can lead to bleeding disorders. These fat-soluble vitamins are important nutritional factors that can be determined in different methods in vegetables. In this work, the simultaneous determination of α-tocopherol, α-tocopheryl acetate, phylloquinone, and menaquinone-4 by gas chromatography-mass spectrometry (GC-MS) has been optimized using both direct injection and solid phase microextraction (SPME). Three different sample pre-treatment approaches based on: (A) solid-liquid-liquid-liquid extraction (SLE-LLE), (B) SLE, and (C) SPME were then applied to extract the target analytes from vegetables samples using menaquinone as internal standard. All the procedures allowed the determination of the target analytes in onion, carrot, celery, and curly kale samples. Similar results were obtained with the three different approaches, even if the one based on SPME offers the best performance, together with a reduced use of solvent, time consumption, and experimental complexity, which makes it the preferable option for industrial applications.

Gas purge micro solvent extraction: A rapid and powerful tool for essential oil chromatographic fingerprints.

In this work, a new an innovative micro liquid extraction technique named "gas purge micro solvent extraction" (GP-MSE) have been tested, hyphenated with gas chromatography-mass spectrometry (GC-MS), to evaluate its capability to extract volatile fractions from vegetal samples respect to classical steam distillation extraction procedure, by comparing essential oil fingerprints from three different Atractylodes species. GP-MSE showed higher extraction capabilities and sensitivities (in particular for semi-volatile components), obtaining more structured essential oil fingerprints with high reliabilities (relative standard deviation of the peak areas between 0.34% and 5.83%), requiring at the same time smaller sample amounts and reduced extraction times. Essential oil profile data were also submitted to principal component analysis and included cosine angle in order to highlight differences among the Atractylodes species under investigation. GP-MSE can be considered an alternative, simple, fast, sensitive and environmentally friendly extraction method, with high extraction efficiencies and reproducibility toward both volatile and semi-volatile compounds.

Volatile organic compound data of ready-to-cook tuna fish-burgers: Time evolution in function of different and/or combined mild preservation technologies and relevant statistical analysis.

Volatile organic compound (VOC) composition from ready-to-cook tuna fish-burgers, prepared with and without a protective microbial strain (Lactobacillus paracasei) and/or stored with modified atmosphere packaging (MAP, 5% O2 and 95% CO2), were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry (HS-SPME-GC-MS) during the burger shelf-life. The collected data showed volatile composition profiles in function of the mild preservation technologies employed and the storage time. Furthermore, statistical data treatment (principal component analysis and Pearson's coefficients) highlighted differences among samples and positive/negative correlations during the storage time. This paper is related to an article already published in LWT (Investigating the effects of mild preservation technology on perishable foods by volatolomics: The case study of ready-to-cook tuna-burgers" https://doi.org/10.1016/j.lwt.2019.108425).

Development of a screening analytical method for the determination of non-dioxin-like polychlorinated biphenyls in chicken eggs by gaschromatography and electron capture detection.

A sensitive and reproducible screening analytical method is here proposed for the determination of six non dioxin-like polychlorinated biphenyls (NDL-PCBs, congener 28, 52, 101, 138, 153, 180) in chicken eggs based on accelerated solvent extraction (ASE) procedure for the fat extraction and determination, a solid phase extraction (SPE) sample clean-up process, and a gas chromatography - electron capture detection (GC-ECD) analysis. The optimized chromatographic separation, in less than 25 min, returned good responses for the six NDL-PCBs in the range of 2.5-60.0 µg L-1, with correlation coefficients always higher than 0.9995. Instrumental limits of detection were between 0.08-0.35 µg L-1, corresponding to 0.05 and 0.23 ng g-1 fat in the matrix, while method detection limits, calculated on spiked egg samples, ranged from 1.6 to 3.5 ng g-1 fat. The method has been extensively validated in terms of selectivity, sensitivity, recovery, precision, ruggedness and measurement uncertainty, following the European Directives.