Gas Chromatography-flame Ionization Detector Research Articles

Lyophilized and Oven-Dried Manilkara zapota Extracts: Characterization and In Vitro, In Vivo, and In Silico Analyses

In this work, extracts from the pulp, peel, and seed of Manilkara zapota were obtained via lyophilization and oven drying. Bromatological analyses were performed to investigate variabilities in the nutritional content of fruits after nine post-harvest days. The phytochemical content of fruits was assessed by gas chromatography flame ionization detector (GC-FID), and their biological performance was studied using in vitro antibacterial and antioxidant assays (DPPH and ABTS) and in vivo toxicity models. Molecular docking was implemented to evaluate the interaction between polar compounds from chicozapote fruits with receptors involved in the pathogenesis of bacterial strains. Results revealed that water or soluble solids content did not vary after post-harvest. It was demonstrated that lyophilization or oven-drying approaches influenced the insoluble, total dietary fiber and digestible carbohydrates among samples. According to GC-FID analysis, it was observed that lyophilization and oven-drying methods also altered the content of myristic and pentadecanoic acids among the obtained extracts. It was noted that the antibacterial and antioxidant activities of extracts were weak due to their MIC (>1000 μg/mL) and IC50 (>2000 μg/mL) values. Still, the toxicity of extracts was poor against Artemia salina nauplii. In silico evaluation unveiled that polar compounds in M. zapota fruits possess a high binding affinity towards the DNA gyrase B of the cultured strains. This study expands the scientific evidence regarding the influence of distinct extraction methods on the nutritional and nutraceutical content of native fruits and the importance of considering additional approaches to enhance their bioactivities.

Chemical Composition and Larvicidal Activity of Essential Oil Extracted from Anemia tomentosa (SAV.) Sw: Study Conducted in vitro and in silico

The essential oil extracted from Anemia tomentosa (EOAT) has shown larvicidal potential against Aedes aegypti, based on methods in vitro and in silico. Chromatographic and spectrometric techniques (gas chromatography-mass spectrometry (CG-MS), gas chromatography-flame ionization detector (GC-FID)), as well as mono and bidimensional nuclear magnetic resonance spectroscopy (NMR) were used to assess 10 essential oil components. Chemical composition of essential oil comprised 87.51% sesquiterpenes, with emphasis on presilphiperfolan-1-ol (42.13%) and silphiperfol-5-ene (19.47%). Larvicidal assay conducted in vitro with EOAT has evidenced potential cytotoxic activity up to 48 h exposure to it; mortality rate observed for A. aegypti larvae exposed to essential oil reached 100%. Study conducted in silico with chemical compounds deriving from the herein investigated plant species has evidenced its potential to inhibit acetylcholinesterase in A. aegypti. Activity of triquinane sesquiterpenes ranging from -6.8 to -8.2 kcal mol-1 stood out in comparison to that of temephos (-7.5 kcal mol-1). Chemical compounds identified in the investigated essential oil presented low human and environmental toxicity, as observed in absorption, distribution, metabolism and excretion, and toxicity (ADMETox) predictions.

Simple and rapid paper-based colorimetric spot test for promethazine screening in recreational drug beverages and pharmaceuticals

This study introduces a paper-based colorimetric spot test for the rapid and cost-effective detection of promethazine, featuring enhanced stability and user-friendliness. The developed device employs a potassium persulfate reagent encapsulated in a xerogel matrix, facilitating a simple chemical oxidation reaction that produces a pink color upon promethazine detection. Color quantification is efficiently achieved using a digital camera, with image analysis performed through ImageJ software to convert color image into a blue intensity scale. Under optimized conditions, the method demonstrates a linear calibration curve within the range of 100–600 mg/L and a detection limit of 20 mg/L. The paper-based colorimetric spot test exhibited good intra-day and inter-day accuracy of the recoveries of 98–102 % and 99–101 %, respectively. Good precision of measurement was also achieved (5.6 % RSD). The xerogel matrix ensures the long-term storage stability of the reagent for three months when stored at both 25 °C and 4 °C, making the device suitable for field applications. When applied to detection of promethazine in recreational drug beverage samples and pharmaceutical formulations, the performance of the proposed method showed no significant statistical differences compared to gas chromatography–flame ionization detection (GC–FID). This low-cost, portable, and disposable tool is suited for onsite screening of promethazine, representing a significant advancement in rapid drug detection methodologies.

Essential Oil from Tetrapanax papyrifer (Hook.) K. Koch: Chemical Composition, Antioxidant Activity, α-Glucosidase Inhibitory Effect Integrating Molecular Docking Analysis.

The present study investigated the chemical composition of essential oil from Tetrapanax papyrifer and evaluated its antioxidant and anti-α-glucosidase activity. Sixty-one essential oil compounds from Tetrapanax papyrifer were identified by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID). The essential oil is rich in sesquiterpenoids (96.05%), with major components identified as β-cubebene (13.96%), caryophyllene (13.43%), α-cubebene (12.12%), copaene (7.89%), δ-cadinene (7.29%), eremophilene (6.15%), humulene (5.26%). The essential oil showed dose-dependent antioxidant activity with IC50 value of 723.15 ± 24.10 μg/mL, 200.74 ± 9.90 μg/mL for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, respectively. Ferric reducing antioxidant power (FRAP) antioxidant capacity was 222.73 ± 25.49 μmol/g. The essential oil exhibited a 17.86 ± 0.56% inhibitory effect against α-glucosidase at 500 μg/mL. Moreover, in silico molecular docking analyses were utilized to validate the in vitro anti-α-glucosidase results further.

A concept for sensor system developments using raw-milk monitoring as a case study

Abstract. In this work, we present a concept for a raw-milk monitoring sensor system aiming at demonstrating a generalized approach for low-cost gas sensor system development in future. These systems are expected to be comparatively less expensive than conventional gas chromatography (GC) systems and can therefore likewise be used by farmers to monitor on-site storage as well as by dairy companies for the inspection of incoming milk and can thus play a significant role in counteracting the waste of milk and its products. This generalizable method is based on three steps: identification of potential milk degradation markers, quantification of these markers, and characterization of metal oxide semiconductor (MOS) sensors for these markers. In the first step, gas chromatography–mass spectrometry (GC-MS) and GC–flame ionization detector (GC-FID)/olfactometry (O) were used to tentatively identify 14 volatile substances in the headspace concentrations above the raw milk. From this, 3-methylbutan-1-ol, hexan-1-ol, pentan-1-ol, acetic acid, and additionally ethanol and ethyl acetate were selected by cross-referencing our results with literature data. In addition, hexanal, 2-methyl-1-propanol, limonene, nonanal, 2-ethylhexan-1-ol, butanoic acid, hexanoic acid, octanoic acid, methyl hexadecanoate, and decanoic acid were identified but not selected as potential markers due to their properties being incompatible with gas mixing apparatus (GMA). In the second step, a proton transfer reaction–MS (PTR-MS) analysis was used to determine the concentration in the headspace, which is in the parts per billion (ppb) range. Investigations of good milk samples and bad milk samples from alpine farms showed that ethanol, 3-methylbutan-1-ol, pentan-1-ol, and hexan-1-ol offered an increasing trend from good to bad milk samples. To enable more precise differentiation, further investigations with a higher sample size are necessary to reveal the feasibility of these markers within the complex matrix of raw milk. In the third step, these selected and literature-confirmed markers were presented to a commercially available sensor, run in a temperature-cycled operation and characterized by a self-developed system. When using ethanol, pentan-1-ol, and hexan-1-ol, a regression model with an accuracy of 42.9 ppb using partial least-squares regression (PLSR) analysis could be established, enabling such sensors to be used in raw-milk monitoring systems in the future.

Authenticity Verification of Commercial Poppy Seed Oil Using FT-IR Spectroscopy and Multivariate Classification

Authenticating poppy seed oil is essential to ensure product quality and prevent economic and health-related fraud. This study developed a non-targeted approach using FT-IR spectroscopy and pattern recognition analysis to verify the authenticity of poppy seed oil. Thirty-nine poppy seed oil samples were sourced from online stores and local markets in Turkiye. Gas chromatography–Flame Ionization Detector (GC-FID) analysis revealed adulteration in 23% of the samples, characterized by unusual fatty acid composition. Spectra of the oil samples were captured with a portable 5-reflection FT-IR sensor. Soft Independent Model of Class Analogies (SIMCA) was used to create class algorithms, successfully detecting all instances of adulteration. Partial least square regression (PLSR) models were then developed to predict the predominant fatty acid composition, achieving strong external validation performance (RCV = 0.96–0.99). The models exhibited low standard errors of prediction (SEP = 0.03–1.40%) and high predictive reliability (RPD = 2.9–6.1; RER = 8.4–13.1). This rapid, non-destructive method offers a reliable solution for authenticating poppy seed oil and predicting its fatty acid composition, presenting valuable applications for producers and regulatory authorities. This approach aids in regulatory compliance, protection of public health, and strengthening of consumer confidence by ensuring the authenticity of the product.

Rapid Determination of Methamphetamine, Methylenedioxymethamphetamine, Methadone, Ketamine, Cocaine, and New Psychoactive Substances in Urine Samples Using Comprehensive Two-Dimensional Gas Chromatography.

Background/Objectives: This study evaluates the applicability of a comprehensive two-dimensional gas chromatography-flame ionisation detection (GC×GC-FID) approach for the simultaneous determination of 12 underivatised psychoactive drugs, including new psychoactive substances, that comprised of amphetamine, methamphetamine, mephedrone, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, α-pyrrolidinovalerophenone, n-ethylpentylone (ephylone), norketamine, ketamine, 3,4-methylenedioxypyrovalerone, methadone, and cocaine. Methods: Separation was effected using a non-polar first dimension (1D) and a polar second dimension (2D) column, demonstrating an improved separation of drug compounds compared to a polar/non-polar column configuration. Interference-free baseline separation of all psychoactive compounds in a urine matrix was achieved within 8 min. The GC×GC-FID method was validated according to the guidelines defined by Standard Practices for Method Validation in Forensic Toxicology. Results: The calibration curves for the 12 psychoactive drugs were well correlated (r2 > 0.99) within the concentration ranges of 50-1500 ng mL-1. Detection limits of 10-20 ng mL-1 were obtained, and good repeatability and reproducibility (CV < 11.4%) were attained for retention times and peak areas. Method recoveries for the small-scale solvent extraction procedure ranged from 96.9 to 114.5%, and bias was between -3.1% and 14.5%. Conclusions: The validated approach was successfully applied for the determination of these illicit compounds in spiked urine samples of different concentrations, highlighting its potential for rapid forensic drug screening.

Differential murine responses to Schistosoma mansoni eggs in the liver and small intestine lead to downmodulation of hepatic but not intestinal periovular granulomas.

To control schistosomiasis mansoni, it is important to attempt preventing the worms' egg-induced pathology in the liver and limiting pathogen transmission following egg exit from the intestines to the exterior. Therefore, the present study aimed to clarify the reasons behind the decades-long riddle of periovular granulomas downmodulation in the liver, but not the small intestine, with the progression of murine schistosomiasis mansoni. Outbred female CD-1 mice were percutaneously exposed to 15 Schistosoma mansoni cercariae. The liver and small intestine were collected from mice harboring a minimum of a worm couple at 8, 12, 16, and 20 weeks post-infection, assessed for egg counts/g and histopathological changes, and used to prepare Triton X-100 extracts. Content of cytokines, saturated and unsaturated fatty acids, triglycerides, cholesterol, reactive oxygen species, and uric acid per mg tissue extract proteins were evaluated using capture enzyme-linked immunosorbent assays, gas chromatography-flame ionization detector, and standard commercially available reagents, respectively. Examination of hematoxylin-eosin-stained tissue sections confirmed the decrease in size and changes in cellular composition of periovular granulomas in the liver but not the small intestine, associated with wide differences in released cytokines types and amounts, and content of the bioactive lipids, arachidonic and docosahexaenoic acids, reactive oxygen species, and uric acid. The results together disclosed that the downmodulation of hepatic, but not the small intestine, circumoval granulomas with the progression of murine S. mansoni naturally results from site- and tissue- specific immunological and biochemical responses to the egg-derived antigens and molecules and suggested that the intestines appear to harbor immune-privileged sites.

Integration of FTIR Spectroscopy, Volatile Compound Profiling, and Chemometric Techniques for Advanced Geographical and Varietal Analysis of Moroccan Eucalyptus Essential Oils.

Eucalyptus essential oil is widely valued for its therapeutic properties and extensive commercial applications, with its chemical composition significantly influenced by species variety, geographical origin, and environmental conditions. This study aims to develop a reliable method for identifying the geographical origin and variety of eucalyptus oil samples through the application of advanced analytical techniques combined with chemometric methods. Essential oils from Eucalyptus globulus and Eucalyptus camaldulensis were analyzed using Gas Chromatography-Flame Ionization Detection (GC-FID) and Fourier Transform Infrared (FTIR) Spectroscopy. Chemometric analyses, including Orthogonal Partial Least Squares-Discriminant Analysis (O2PLS-DA) and Hierarchical Cluster Analysis (HCA), were utilized to classify the oils based on their volatile compound profiles. Notably, O2PLS-DA was applied directly to the raw FTIR data without additional spectral processing, showcasing its robustness in handling unprocessed data. For geographical origin determination, the GC-FID model achieved a Correct Classification Rate (CCR) of 100%, with 100% specificity and 100% sensitivity for both calibration and validation sets. FTIR spectroscopy achieved a CCR of 100%, specificity of 100%, and sensitivity of 100% for the calibration set, while the validation set yielded a CCR of 95.83%, specificity of 99.02%, and sensitivity of 94.44%. In contrast, the analysis based on species variety demonstrated 100% accuracy across all metrics CCR, specificity, and sensitivity-for both calibration and validation using both techniques. These findings underscore the effectiveness of volatile and infrared spectroscopy profiling for quality control and authentication, providing robust tools for ensuring the consistency and reliability of eucalyptus essential oils in various industrial and therapeutic applications.

Fatty Acids Analysis in Dairy Products via GC-FID Methodology: Leveraging PS/SNW-1 Nanofibers for Enhanced PT-µSPE

In an effort for rapid and simultaneous determination of multiple fatty acids in dairy products, a newly developed sorbent based on polystyrene/Schiff base network-1 (PS/SNW-1) electrospun nanofibers were used for pipette tip-micro solid phase extraction (PT-µSPE) with gas chromatography-flame ionization detector (GC-FID). The porous and hydrophobic nature of PS, in the presence of the SNW-1 as a covalent-organic framework with robust resistance in aqueous and acidic solutions, acceptable thermal stability, a substantial surface area, and an accumulated π-electron system, offers a sorbent with exceptional extraction efficiency. This innovative approach overcomes the limitations encountered when utilizing SNW-1 and PS individually, such as back pressure, leakage, and limited reusability.Under optimum conditions, an outstanding linear dynamic range was obtained in the range of 0.3–30000 µg L−1 for myristic acid, 0.3–45000 µg L−1 for palmitic acid, and 6.0–60000 µg L−1 for stearic acid and oleic acid. Additionally, the method demonstrated a low limit of detection (LOD ≤ 1.8 µg L−1) and limit of quantification (LOQ ≤ 6.0 µg L−1), along with relative standard deviations within the range of 1.19–5.59 % for within-day and 2.83–5.93 % for between-day analyses. Furthermore, satisfactory relative recovery and sorbent reusability were also achieved.

Volatile constituents, physicochemical properties and antibacterial activity of black and fresh garlic (Allium sativum L.)

Black garlic is produced from fresh garlic by heat treatment at a controlled temperature and humidity for a certain period of time. The processing conditions are responsible for a series of changes in the plant material that culminate in the alteration of its physicochemical and bioactive properties. This study evaluated the physicochemical properties of fresh and black garlic, as well as the chemical composition and antibacterial activity of their essential oils. Regarding the physicochemical parameters evaluated, there was a significant difference in all parameters, showing that black garlic bulbs had a lower pH, water activity, and L* and b* parameters and higher values of ash, acidity and proteins. The chemical characterization of the essential oils from two batches of fresh garlic (FG1 and FG2) and two batches of black garlic (BG1 and BG2) was carried out using gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. In the case of fresh garlic essential oil, diallyl disulfide and diallyl trisulfide represented more than 70% of the chemical composition of the two batches evaluated. For black garlic essential oils, 4-methyl-1,2,3-trithiolane and 5-methyl-1,2,3,4-tetrathiolane were the main components. Both fresh and black garlic essential oils have been shown to be rich in organosulfur compounds. As for antimicrobial activity, the black garlic essential oil showed greater inhibitory and bactericidal potential against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa compared to fresh garlic. The black garlic essential oils evaluated are more promising for the microbiological control of food bacteria than those from fresh garlic.

The Impact of Feed Management Technologies on Mineral Oil Hydrocarbons (MOH) Contamination: A Comparative Farm Level Approach

Legislative frameworks about contamination are often limited to foods and underestimate the role of animal nutrition for safe production. This study aims to assess mineral oil hydrocarbon (MOH) contamination in feed and identify the technological factors that are contributing to this issue, particularly focused on mechanised harvesting and processing. Three dairy farms, classified by contamination risk (low, medium, and high), were selected, and fifteen feed samples were analysed using the coupled liquid chromatography–gas chromatography–flame ionisation detection (LC–GC–FID) method, with a microwave-assisted saponification (MAS) step to determine mineral oil saturated (MOSH) and aromatic (MOAH) hydrocarbon levels. Important contamination levels were observed depending on the technological development of each farm. MOSH levels ranged from 11.4 mg/kg to 81.40 mg/kg, while MOAH levels ranged from 0.5 mg/kg to 4.6 mg/kg. MOAH accounted for 4.74% of the total MOH content. The results showed a connection between feed production technologies and MOH contamination levels. Factors such as the mechanisation, the machinery used, and the storage conditions were potentially contributors to contamination, while chemical treatments had no direct impact but some potential risks. The contamination levels varied across farms, indicating certain contamination sources beyond technological factors. Advanced technological measures and proper equipment maintenance are suggested to mitigate MOH contamination risks in feed.

Comparative characterization of key compounds of Sauce-flavored rounded-Baijiu in northern and southern China and the potential possibility of similar quality of their combined products

The flavor characteristics and sensory attributes of northern Sauce-flavored rounded-Baijiu (NR) and southern Sauce-flavored rounded-Baijiu (SR) were systematically studied. A total of 56 major flavor compounds were quantitatively detected through Gas chromatography-flame ionization detection (GC-FID). Besides, 20 kinds of key aroma compounds and 7 significant differential compounds were identified by calculating the odor activity values (OAVs) and orthogonal partial least squares discriminant analysis (OPLS-DA) of flavor compounds in NR and SR. And then, the relationship between sensory attributes and key aroma compounds were investigated by network analysis. Furthermore, A group of combined-Baijiu (the ratios of the first to the fifth round of Sauce-flavored Baijiu in the north (NR1–5) were 5 % NR1, 35 % NR2, 30 % NR3, 20 % NR4, 10 % NR5) was closer to the style known for blending different proportions of SR into the combined-Baijiu. This study provided a guiding significance for the standardized production of sauce-flavored Baijiu.

Fat extraction methodology can affect the food fatty acid profile: Improvement of a protocol more environmentally friendly

Fatty acids (FAs) are biochemical components of food, essential for human health due to their numerous biological functions. However, many of then if consumed in excess can trigger disfunctions/illness. Therefore, analytical methods, such as gas chromatography (GC-FID) are essential for the accurate identification and quantification of FAs, playing an important role in food safety and quality assessment. The aim of this study was to compare two FAs extraction protocols and to adapt, optimize, and validate a new one for food FAs extraction, considering the principles of green chemistry (sustainability and environmentally friendly). The research included four main steps: (A) comparison of two FAs extraction protocols for Gas Chromatography Flame Ionization Detector (GC-FID) analysis; (B) adaptation and optimization of four new extraction protocols; (C) verification of the most promising protocol; and (D) evaluation of the greenness profile. Comparatively, the PE2 protocol detected a greater diversity of FAs and a wider range of medium/long chain saturated fatty acids (SFA), but with divergences from values declared on food labels, mainly in the quantification of unsaturated fatty acids (UFA), unlike PE1, which presented lipid fraction values closer to nutritional information and greater extraction of short/medium chain FAs. The improved protocol, PE6, proved to be more efficient in extracting short, medium, and long chain FAs, as well as having SFA and UFA values closer to nutritional values in different food matrices. Furthermore, PE6 also showed improvements in relation to green chemistry aspects, presenting a higher greenness profile score, which indicates that it is more sustainable and generates less environmental impact. These results underscore the importance and relevance of continuing to develop analytical methods for food that are both effective and environmentally responsible.

Phytochemical profiling and evaluation of in vitro antioxidant and in vivo anti-inflammatory activity of Neolitsea pallens essential oil

This study aims to determine the chemical composition, in vitro antioxidant, and in vivo anti-inflammatory properties of Neolitsea pallens essential oil (NPEO). The essential oil was isolated using hydrodistillation in a Clevenger-type apparatus. The qualitative and quantitative composition of essential oil was determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID), respectively. A total of 42 compounds were identified, accounting for 91.15% of the oil. The major components included β-caryophyllene (32.72%), germacrene D (9.11%), caryophyllene oxide (8.11%), β-sabinene (6.60%), and β-elemene (4.46%). NPEO demonstrated significant antioxidant activity in DPPH and ABTS+ free radical scavenging assays, with IC50 values of 49.05 μg/mL and 5.8 μg/ mL, respectively. In the in vivo anti-inflammatory tests, NPEO exhibited a maximum inhibition of 60.57% in the carrageenan-induced paw edema model and 50% in the xylene-induced ear edema model, both at a dose of 20 mg/kg. The presence of sesquiterpene hydrocarbons and oxygenated sesquiterpenes in NPEO may contribute to its enhanced antioxidant properties thereby reducing the inflammation in animal models.

Comparative mosquitocidal and repellence activities of essential oil, nanoemulsion and main terpenes of Deverra tortuosa against Aedes albopictus with insights into the non-target effects

There is an urgent and renewed interest in searching for effective and green pesticides to control mosquitoes. In this framework, the essential oil (EO) of the plant Deverra tortuosa was hydrodistilled, and analysed using gas chromatography-flame ionisation detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Dillapiole (40.2%), elemicin (8.1%), and myristicin (6.3%), phenylpropanoids, and sabinene (4.3%) a common monoterpene, were found to be the major EO components. The oil nanoemulsion (ONE) was developed adopting a green protocol, and then characterised. The EO, ONE, and terpenes, particularly the phenylpropanoids possessed considerable mosquitocidal bioactivity against the Asian tiger mosquito, Aedes albopictus. A percentage of 100% larval mortality was recorded when insects were treated with a concentration of 40 μL/mL of ONE after 24 hours of treatment, while double of this concentration from EO and dillapiole was required to achieve the same activity. The LC50’s against larvae ranged between 7.6 and 60.7 μL/mL. For adults, LC50’s ranged between 6.4 and 50.9 μL/L. At sub-lethal concentrations (0.625-5.0 μL/cm2), EO materials significantly repelled Ae. albopictus, where a concentration of 5.0 μL/cm2 of EO and ONE provided 100% protection for up to180 min. As a proposed mechanism of action, the EO materials considerably inhibited the activity of acetylcholinesterase (AChE). The test materials were safe for the mosquitofish, Gambusia affinis, a common larvivorous fish, and Eisenia fetida earthworm. Test materials were also safe for the white albino rat in an oral bioassay at a limit dosage of 3500 mg/kg b.wt. The findings support the use of the EO, nanoemulsion, and phenylpropanoids of D. tortuosa as environmentally benign natural mosquitocodes to control Ae. albopictus.

A three-dimensional nitrogen-rich conjugated microporous polymer for solid-phase microextraction of nitroaromatic compounds from environmental water and soil samples

Nitroaromatic compounds (NACs), as a kind of important chemical intermediates, are widely used in industrial productions. However, NACs have carcinogenic effect and their residues may pose harm to human health. Therefore, there is necessity to set up effective analytical method to monitor them in some environmental samples. However, because of their low concentrations in real samples, they need to be enriched by an effective adsorbent before the subsequent instrumental detection. In this work, a three-dimensional nitrogen-rich conjugated microporous polymer (DCT-Try-CMP) was synthesized with 3,6-dichloro-1,2,4,5-tetrazine and triptycene as monomers via Friedel-Crafts reaction. It presented a good adsorption capability for the NACs. After optimization, a solid-phase microextraction with DCT-Try-CMP fiber combined with gas chromatography-flame ionization detection for the quantitation of trace NACs in environmental water and soil samples was developed. The limits of detection of the method (S/N = 3) for environmental water and soil samples were 0.08–0.30 μg L−1 and 1.00–5.00 ng g−1, and the limits of quantification (S/N = 9) were 0.27–0.90 μg L−1 and 3.00–15.0 ng g−1, respectively. The linear quantification response ranges for the analytes were 0.27–200 μg L−1 and 3.00–1000 ng g−1 for water and soil samples, respectively. For water samples at the analytes concentrations of 5.00, 50.0 and 100 μg L−1, the method recoveries ranged from 82.2 % to 120 % and for soil samples at the concentrations of 15.0, 200 and 400 ng g−1, the method recoveries fell in the range from 80.2 % to 120 %. The method provides a sensitive and effective approach for monitoring trace NACs in environmental water and soil samples.

Identification and determination of usnic acid and fatty acid from various lichen species in arequipa, Peru, as well as antibacterial and antioxidant capacity

Seven species of lichens such us Umbilicaria aff. calvescens, Hypotrachyna enderythraea, Punctelia graminicola, Cladonia chlorophaea, Xanthoparmelia farinose, Psiloparmelia distincta (rock and tree substrates; rs and ts), and Usnea durietzii were collected from the province of Arequipa - Peru. Their usnic acid (UA) and fatty acid (FA) amounts in methanol-acetone were determined by High-performance liquid chromatography with diode-array detection (HPLC-DAD) and Gas chromatography-flame ionization detector (GC-FID). The antimicrobial activities of these extracts were evaluated against Staphylococcus aureus ATCC strains (43300, 29213, 25923 and 700699), Escherichia coli strains (O157:H7 and ATCC 10536), Salmonella enterica sv typhimurium ATCC 14028, Candida albicans ATCC 90028 and Candida. tropicalis ATCC 750T. In addition, antioxidant capacity was also studied by Total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical, 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid (ABTS) radical cation and Ferric Reducing Antioxidant Power (FRAP) assays. The UA contents in all the studied lichen species varied between 0.017 and 0.304 %. Among all the tested extracts, Usnea durietzii had the highest total FA concentration (5.81 mg/g). P. distincta (rs) was active against S. aureus strains (MIC = 0.02–0.2 mg/mL) as well as C. albicans (MIC = 4 mg/mL) and C. tropicalis (MIC = 3 mg/mL). P. distincta (ts) displayed moderate total phenol content (TPC = 29.1 ± 1.6 mg GAE/g) and antioxidant capacity evidenced by scavenging DPPH (IC50 = 1.45 ± 0.03 mg/mL) and ABTS (18.2 ± 0.2 mg TE/g) radicals, but it showed high values of FRAP (1953 ± 87 μM Fe2+/g). Our findings indicate that P. distincta (rs) could be considered as a potential antimicrobial metabolites source whereas P. distincta (ts) and Puntelia graminicole for polyphenols with antioxidant compound.

Comparative study of chemical constituents and biological potency in Lantana camara Linn. leaf essential oil collected from two different sites in Northeast India

The ubiquitous occurrence of Lantana camara highlights its exceptional ecological versatility. Leaves of L. camara were obtained for this study from two different locations of NE, India. Hydro distillation was used to extract the essential oils from the leaves, and gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detection (GC-FID) were used to study the chemical profiles of the isolated oils. The essential oil analysis detected 35 components in total essential oil from Location 1 (BLCEO) while in Location 2 essential oil (JLCEO), 29 components were identified. Caryophyllene, humulene and sabinene were present in considerably major amounts in both BLCEO and JLCEO, though variation in area percentage was seen. The anti-oxidant properties of BLCEO were better than that of JLCEO. The BLCEO has also exhibited better results in inhibiting acetylcholinesterase. However, both the essential oils did not show any prominent results in α-amylase inhibitory assay and anti-tyrosinase activity. In this study, the phytochemical composition and their effect on the bioactivity of both samples were observed. The chemical constitution of L. camara essential oils (LCEO) and its possible ecological ramifications have also been well explained.

Application of magnetic AlFu MOF nanocomposite for the extraction and preconcentration of some pesticides from different distillates

This research used a magnetic AlFu nano-metal-organic framework as an adsorbent for the first time. This approach extracts and preconcentrates eight pesticides from various distillates through a two-step process: magnetic dispersive micro solid phase extraction and dispersive liquid-liquid microextraction. Initially, the nanocomposite is dispersed into a sample solution containing the pesticides and Na2SO4. The target pesticides are then adsorbed onto the nanocomposite, which is subsequently isolated from the aqueous phase using an external magnetic field. Acetonitrile is used to elute the adsorbed analytes pesticides from the nanocomposite surface. The resulting acetonitrile extract, containing the concentrated pesticides, is then mixed with a tiny amount of another solvent and injected into a NaCl solution. Centrifugation allows the organic phase, enriched with the pesticides, to settle down. An aliquot of this organic layer is then analyzed using a gas chromatography-flame ionization detector. Optimization of the procedure led to favorable performance, including good extraction recovery of the pesticides (68–98 %), significant enrichment (enrichment factors of 340–489), a wide range of detectable concentrations (2.90–1400 µg L−1), and low detection (0.15–0.88 µg L−1) and quantification limits. (0.49–2.90 µg L−1)