Gas Chromatography-flame Ionization Detector Research Articles

Chemical composition and biological activities of essential oils of seven Cultivated Apiaceae species

The Apiaceae family contains many species used as food, spice and medicinal purposes. Different parts of plants including seeds could be used to obtain essential (EO) oils from members of the Apiaceae family. In the present study, EOs were components obtained through hydrodistillation from the seeds of anise (Pimpinella anisum), carrot (Daucus carota), celery (Apium graveolens), dill (Anethum graveolens), coriander (Coriandrum sativum), fennel (Foeniculum vulgare), and cumin (Cuminum cyminum). EO constituents were determined with Gas Chromatography/Mass Spectrometry (GC–MS) and Gas Chromatography/Flame Ionization Detector (GC-FID) and their antioxidant capacities were determined with the cupric reducing antioxidant capacity (CUPRAC) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) methods. The antimicrobial activity of EOs were tested against four pathogenic bacteria. Phenylpropanoids in anise (94.87%) and fennel (92.52%), oxygenated monoterpenes in dill (67.59%) and coriander (98.96%), monoterpene hydrocarbons in celery (75.42%), mono- (45.42%) and sesquiterpene- (43.25%) hydrocarbons in carrots, monoterpene hydrocarbon (34.30%) and aromatic hydrocarbons (32.92%) in cumin were the major compounds in the EOs. Anethole in anise and fennel, carotol in carrot, limonene in celery, carvone in dill, linalool in coriander, and cumin aldehyde in cumin were predominant compounds in these EOs. The high hydrocarbon content in cumin EO gave high CUPRAC activity (89.07 µmol Trolox g−1), and the moderate monoterpene hydrocarbon and oxygenated monoterpene content in dill EO resulted in higher DPPH activity (9.86 µmol Trolox g−1). The in vitro antibacterial activity of EOs against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli was evaluated using the agar diffusion method and the minimum bactericidal concentration was determined. Coriander, cumin and dill EOs showed inhibitory effect against all tested strains except P. aeruginosa. While fennel and celery EOs were effective against E. coli and B. cereus strains, respectively, anise and carrot EOs did not show any antibacterial effect against the tested bacteria. Hierarchical Cluster Analysis (HCA) produced four groups based on EO constituents of seven species. The potential adoption of the cultivated Apiaceae species for EO extraction could be beneficial for the wild species that are endangered by over collection and consumption.

Nutritional Evaluation of Fish Scale of Selected Saline and Fresh Water Fish Species

Fish scale is the major waste materials of fish having different vital nutrients, proteins, and fatty acids. But unfortunately, it has not been drawn much attention due to want of available researches and information. So, the present research has been emphasized on the exploration of proximate compositions and fatty acid profile in two fresh water fish L. rohita and C. idella as well as saline water fish L. calcarifer and T. ilisha. All the experiments were carried out according to International Organization for Standardization (ISO) and Association of Official Analytical Chemists (AOAC). The individual percentage of fatty acid was identified and quantified, using Gas Chromatography-Flame Ionization Detector (GC-FID) and the prominent percentage of docosanoic acid was found as 25.96±0.05 %, 51.74±0.04 %, 56.58±0.01 %, and 32.88±0.04 % in L. rohita, C. idella, L. calcarifer, and T. ilisha, respectively. Besides, among the mono and poly unsaturated fatty acids, palmitoleic acid and linolenic acid were traced in higher amount respectively, in all fish species. The quality of fish scale oil was evaluated using saponification value, iodine value, ester value, acid value, percentage of free fatty acid, and percentage of glycerin that was found as 183.78±0.34 mg KOH/g, 29.93±0.21 mg I2/g, 175.31±0.31 mg KOH/g, and 17.53±0.24 mg KOH/g, in L. rohita, T. ilisha, L. rohita, and L. rohita, respectively. The proximate analyses showed that the maximum percentage of moisture (53.20±0.23 %) and lipid (1.42±0.11 %) was noticed in L. rohita whistle, the maximum percentage of ash (18.70±0.27 %) and protein (32.37±0.26 %) was found in T. ilisha. Furthermore, among the different minerals, calcium was found as higher amount than others minerals in all four species.

Urinary biomonitoring of fuel ether oxygenates using a needle trap device packed with a novel molecularly imprinted polymer surface modified Zeolite Y

This study introduces an innovative needle trap device (NTD) featuring a molecularly imprinted polymer (MIP) surface-modified Zeolite Y. The developed NTD was integrated with gas chromatography-flame ionization detector (GC-FID) and employed for analysis of fuel ether oxygenates (methyl tert‑butyl ether, MTBE, ethyl tert‑butyl ether, ETBE, and tert‑butyl formate, TBF) in urine samples. To optimize the key experimental variables including extraction temperature, extraction time, salt concentration, and stirring speed, a central composite design-response surface methodology (CCD-RSM) was employed. The optimal values for extraction in the study were found to be 51.2 °C extraction temperature, 46.2 min extraction time, 27 % salt concentration, and 620 rpm stirring speed. Under the optimized conditions, the calibration curves demonstrated excellent linearity within the range of 0.1–100 μg L−1, with correlation coefficients (R2) exceeding 0.99. The limits of detection (LODs) for MTBE, ETBE, and TBF were obtained 0.06, 0.08, and 0.09 μg L−1, respectively. Moreover, the limits of quantification (LOQs) for MTBE, ETBE, and TBF were obtained 0.18, 0.24, and 0.27 μg L−1, respectively. The enrichment factor was also found to be in the range of 98–129.The NTD-GC-FID procedure demonstrated a high extraction efficiency, making it a promising tool for urinary biomonitoring of fuel ether oxygenates with improved sensitivity and selectivity compared to current methods.

Risk Assessments of Polycyclic Aromatic Hydrocarbons in the Surface Sediments of Drinking Water Sources in Ifite Ogwari, South-East Nigeria

ABSTRACT Surface water is the main source of drinking water in Ifite Ogwari, Anambra State, South-East Nigeria. In aquatic environments, sediment functions as both a source and a sink of polycyclic aromatic hydrocarbons (PAHs). To determine the level of pollution, health concerns to people and the environment, and potential sources of PAHs in the surface water sediments in Ifite Ogwari, sediment samples were collected from 9 surface water sources used for drinking by Ifite Ogwari people and were analyzed using a Gas Chromatography/Flame Ionization Detector (GC-FID). In all sediment samples, only 11 PAHs out of 16 United States Environmental Protection Agency (USEPA) priority PAHs were detected while 5 were below detectable limits. The concentration of benzo[a]anthracene was high but detected in only 2 sediment samples while fluoranthene has a relatively close concentration across all samples. Benzo[k]fluoranthene has the highest concentration compared to other PAHs in the samples while benzo[a]pyrene has the lowest concentration across all samples. Atammele sediment was analyzed as the most carcinogenic followed by Isiachala with concentrations of 84.23 ng/µL and 51.92 ng/µL respectively. Ube stream sediment has the lowest concentration of PAHs (11.74 ng/µL). Ecological risk of the PAHs revealed a sediment-to-sediment variation in the risk profile. Human health risk assessment depicts that hazard index and total cancer risk for adults and children ranged from 2.3E-07 - 2.57E-05 and 4.85E-07 - 5.43E-05 respectively. Pyrogenic activities are the main source of PAHs in the sediments. The results provide a guide for monitoring PAHs pollution and protecting drinking water sources.

Exploring volatile organic profiles of red pen inks based on gas-chromatography-flame ionization detection (GC-FID) and chemometric methods for forensic investigation purposes

Criminal cases involving questioned documents often cause the loss of a huge amount of money in a country. Red ballpoint pen inks found on threatening notes, or any official documents are potentially encountered by a forensic document examiner as questioned documents. Identifying sources of the questioned ink entries is paramount to revealing the authenticity or sources of the document. Despite the multitude of works being devoted to discriminating pen inks by their sources, very little is focused on the volatile fractions. In this study, the volatile compositional profiles of ten types of red ballpoint pen inks as acquired by gas chromatography-flame ionization detection (GC-FID) were studied using various multivariate exploratory tools. Scores plot of principal component analysis reveals that inter-pen brand variation is higher than the inter-pen type variation. Meanwhile, hierarchical clustering analysis showed that 6 of the 10 pen types and all five pen brands could be discriminated. In conclusion, volatile organic compositions of red pen inks are useful in classifying the pen inks by brands. The outcome of the study will provide vital insight into the potential of volatile organic profiles in discriminating red pen inks sold in Malaysia.

Phytochemical Screening and GC-FID Identification of Bioactive Compounds in N-hexane, Ethylacetate and Methanol Fractions of Methanolic Leaves Extract of Azanza garckeana

Azanza garckeana is a tropical African plant commonly used for food and medicine. This study was aimed at evaluating the antioxidant, phytochemicals and the bioactive compounds present in n-hexane, ethylacetate and methanol fractions of the methanolic extract of Azanza garckeana leaves. Phytochemical screening and antioxidant assayed were carried out using standard methods, while bioactive compounds were analyzed using gas chromatography-flame ionization detector (GC-FID). The phytochemical compositions revealed considerable level of tannins and saponins with moderate concentration of flavonoids and steroids in the methanol fraction; whereas n-hexane fraction also showed considerable amount of tannins followed by saponins and a low concentration of steroids. However, ethylacetate fraction had the highest yield of tannins, steroids, and terpenoids which were significantly (p< 0.05) higher than methanolic fraction and n-hexane fraction respectively. The antioxidant activity of the methanolic crude extract of A. garckeana leaves showed that the % DPPH radical scavenging activity of the crude extract increased with decreased in concentration when compared with the standard antioxidant (ascorbic acid). The result of GC-FID analysis revealed the presence of nineteen constituents in n-hexane fraction, while ethylacetate and methanol fractions each have twenty constituents. This result showed that Azanza garckeana leaves contain health-promoting bioactive compounds with potent antioxidants.

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

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

Mycoremediation of polyaromatic hydrocarbon contaminated anoxic ecosystem by &lt;i&gt;Trichoderma&lt;/i&gt; species in synergy with &lt;i&gt;Bacillus&lt;/i&gt; species

Fungi-base remediation is a cheap, effective and ecofriendly procedure for the cleanup of crude oil contaminated ecosystem. The study investigated the reduction of lag in crude oil degradation by Trichoderma in synergy with Bacillus in biofilm mode Sediment samples were collected from Bodo Ogoni River State using random stratified method.at depth 0 – 15 cm and 15 – 30 cm. The experimental setup consists of consortium of 1 % and 50 % crude oil (bonny light) with Trichoderma inoculum alone and/or Trichoderma and Bacillus inoculum for sixty (60) days. Microbiological test, Biochemical test, Physiochemical test (pH, conductivity) salt (nitrate, phosphate, sulphate) metal (lead, nickel, chromium, vanadium, iron) and total petroleum hydrocarbon and polyaromatic hydrocarbon using Gas chromatography flame ionization detector. Trichoderma koningopsis strain (MT111912.1): accession no (ON564694) and Bacillus velezensis strain (ON287164.1) accession no. (ON584354) were molecularly identified. 1 % crude oil Trichoderma only setup recorded 33.3 % reduction of PAHs while Trichoderma and Bacillus 1 % crude oil setup recorded 78.8 %. The 50 % crude oil Trichoderma only setup recorded 57.5 % reduction of PAHs while Trichoderma and Bacillus 50 % crude oil setup recorded 90.8 %. For TPH 1 % crude oil Trichoderma only setup recorded 29.9 % reduction while Trichoderma and Bacillus recorded 71.9 %. The 50 % crude oil Trichoderma only setup recorded 49.2 % reduction of while Trichoderma and Bacillus 50 % crude oil setup recorded 85.8 %. The study revealed that Trichoderma species can degrade polyaromatic hydrocarbon and total petroleum hydrocarbon faster in synergy with Bacillus.

Evaluation of the degrading potentials of plasmid and non–plasmid borne soil bacterial strains on bonny light crude oil

This study was undertaken to evaluate the degrading potentials of plasmid and non–plasmid borne soil bacterial strains on Bonny light crude oil. Enrichment technique, turbidometric test, plasmid curing test as well as gas chromatographic flame ionization detection technique was adopted for isolating and evaluating the oil degrading capabilities of the selected bacterial strains. The preliminary physicochemical results revealed that pH was recorded slightly neutral, higher conductivity (0.41 to 0.44 μS/cm), higher organic carbon (2.32 to 4.34 %) but lower nitrogen and phosphorus contents (0.27 % and 10.11 kg) as well as lower water holding capacity was noted, respectively. The results indicated that 22 out of the 60 isolated bacterial strains had high crude oil degrading potentials (A600nm &gt; 0.3). The result further indicated that bacterial strains belong to various species which are Bacillus cereus C12, Pseudomonas aeruginosa KAVK01, Bacillus licheniformis 126, Ochrobacterium intermedium E85b, Bacillus subtillis SDDlas, Bacillus subtillis LK4.5, Enterobacter cloacae GEBRI III and Bacillus cereus So24. Plasmid borne P. aeruginosa strain KAVK01 was the best degrader with 88 % remediation efficiency within the period while the plasmid cured P. aeruginosa strain KAVK01 had 65 % degradation with the order of n – alkane hydrocarbon degradation: (n-C8 - n-C17) &gt; (n-C18 - n-C25) &gt; (n-C26 - n-C32). The data obtained from the current study could help in the selection of bacterial species, most especially plasmid borne bacteria that can be employed in the restoration of oil contaminated soil ecosystem in the Niger Delta region of Nigeria.

Development of a GC-FID method for quantitative characterisation of polyglycerols in polyglycerol polyricinoleate (PGPR) present in a lipid matrix

PGPR is an emulsifier (E476) widely used in the food industry. In this study, a gas chromatography–flame ionisation detection (GC-FID) method was developed for the quantitative characterisation of the polyglycerol composition of PGPR. The method was validated to analyse quantitatively the polyglycerol species in neat PGPR products and in PGPR samples present in a lipid matrix. This method consists of saponification, acidification and petroleum ether extraction to remove interfering fatty acids, neutralisation, silylation and finally GC-FID analysis. Phenyl β-D-glucopyranoside was used as internal standard as sorbitol proved unsuitable due to its susceptibility to interference from Na/K chloride during silylation. The response factors of glycerol and diglycerol towards phenyl β-D-glucopyranoside were determined using pure standards, while response factors of polyglycerols with a degree of polymerisation of at least 3 could be reliably estimated according to an effective carbon number (ECN) approach. The validity of the method applied to PGPR samples was further supported on the basis of a mass balance considering the experimentally determined polyglycerol and fatty acid content. Moreover, recoveries of di-, tri-, tetra- and pentaglycerol were more than 95% for various PGPR samples added to two different lipid matrices at 2 wt% and 5 wt% concentrations. Furthermore, the method proved to be very repeatable (with relative standard deviation values below 2.2%). On the other hand, the inevitable presence of glycerol in the lipid samples caused fouling of the detector and column overloading, requiring frequent cleaning of the detector and trimming off part of the column.

Enzyme-Based Antiviral Potential of Cinnamomum verum J. Presl. Essential Oil and Its Major Component (E)-Cinnamaldehyde.

In the present study, Cinnamomum verum J. Presl. bark essential oil and its main component cinnamaldehyde was evaluated in vitro for neuraminidase (NA), transmembrane serine protease (TMPRSS2), and angiotensin converting enzyme 2 (ACE2) inhibitory activities. The chemical composition of C. verum essential oil was confirmed by both gas chromatography-mass spectrometry (GC/MS), and gas chromatography-flame ionization detection (GC-FID), where 75.9% (E)-cinnamaldehyde was the major component. The ACE2, NA, and TMPRSS2 enzyme inhibitions of C. verum bark essential oil at 20 μg/mL concentration, and (E)-cinnamaldehyde (5 μg/mL) were calculated and compared in the range of 54.2-89.9%. Molecular docking results supported that (E)-cinnam-aldehyde was specific to ACE2 with 89.9% inhibition. Our findings suggest further in vivo studies to confirm the effective and safe use of the essential oil as well as the (E)-cinnamaldehyde.

Poly-(ionic liquid) coated with magnetic nanoparticles for micro solid phase extraction of polycyclic aromatic hydrocarbons in food samples

Poly(methyl methacrylate-vinyl imidazole bromide) (poly-MMA-IL)-grafted magnetic nanoparticles were successfully developed and applied in the micro-magnetic solid phase extraction (μ-MSPE) for 16 types of polycyclic aromatic hydrocarbons (PAHs) from tea, fried food, and grilled food samples via gas chromatography flame ionization detector (GC-FID). One variable at a time (OVAT) and response surface methodology (RSM) were used for efficient optimization. The validation method showed a good coefficient of determination (R 2) ranging from 0.9901 to 0.9982 (n = 3) with linearity of 0.2 μg L−1–500 μg L−1. Detection and quantification limits were 0.06 µg L−1–0.32 µg L−1 and 0.18 µg L−1–0.97 µg L−1. Additionally, satisfactory reproducibility was attained with intra-day and inter-day precisions having RSD ranges of 3.6%–11.1%. The spiked recovery value of 16 PAHs in fried food, grilled food and tea samples obtained from the night market in Malaysia ranged from 80%–12%, respectively.

Methanol intoxication in the central region of Saudi Arabia: Five case studies

Outbreaks of methanol poisoning have been described in the medical literature worldwide. However, the few outbreaks that have occurred in Saudi Arabia remain undocumented. This is especially noteworthy in light of the fact that Saudi Arabia is among the countries that explicitly prohibit the usage of alcoholic beverages and recreational drugs. Herein, we describe five cases of methanol poisoning in Saudi Arabia. The first three comprise patients admitted to the emergency room (ER) with signs of methanol toxicity, such as heart palpitations, vomiting, and blurred vision; otherwise, those patients were considered medically free. The remaining two cases were examined postmortem. A headspace gas chromatography-flame ionization detector was used to test blood, vitreous humor, and urine samples for methanol. Specific lethal concentrations of methanol were defined based on published case studies as 23–740 mg/dL in blood and 12–396 mg/dL in vitreous humor. In postmortem cases of our present study, samples exhibited lethal concentrations: 118 and 257 mg/dL in blood, 116.3 and 283 mg/dL in vitreous humor. In ER cases, methanol concentrations in urine samples were lower, at 7.5, 9.1, and 20.9 mg/dL; however, toxic symptoms were still observed. These case studies indicate that it is necessary to raise community awareness about the risk of methanol poisoning in order to minimize future poisoning epidemics.

Derivation of a no significant risk level (NSRL) of acrylamide in potato-based synthetic models and validation by NIR spectroscopy

The composition of raw potato-based products, mainly sugars and amino acids, plays a vital role in acrylamide formation after thermal treatment. The aim of the present study was to derive a No Significant Risk Level (NSRL) of acrylamide in potato-based synthetic models and validate it using Near Infrared Radiation spectroscopy (NIR). Therefore, NIR spectroscopy was chosen to validate gas chromatography Flame-Ionization Detector (GC-FID) concerning acrylamide detection in synthetic potato models and real potatoes. Subsequently, the Megazyme kit, High-Performance Liquid Chromatography, and GC-FID were applied to measure sugars, amino acids, and acrylamide. Findings revealed that peaks at 4439-4477 cm-1 were assigned to indicate acrylamide presence in all potato samples. Moreover, sucrose and asparagine had a significant impact on acrylamide. The prototype model unveiled the best combination among all potato models regarding the least acrylamide formation (Agria > Monalisa > Kennebec > Prototype). Mathematical equations were derived to calculate acrylamide concentration that should be below the threshold LOQ < 166.6 µg.kg-1, thus indicating an NSRL of acrylamide in the produced potato snacks if Agria and Monalisa cultivars were used.

The Effect of Fermentation Time, pH and Saccharomyces Cerevisiae Concentration for Bioethanol Production from Ulva Reticulata Macroalgae

Research has been carried out on the effect of pH, fermentation time and yeast concentration on bioethanol production through hydrolysis using a CEM (Ceramic Elekctromagnetic Microwave) synthesizer and bioethanol production from Ulva reticulata seaweed. Ulva reticulata seaweed contains carbohydrates in the form of heteropolysaccharides such as glucose, arabinose, ramnose and xylose which are very abundant and suitable for conversion into bioethanol because the people of Timor Island do not use them as food. The carbohydrate content of Ulva reticulata seaweed can be converted into hexose and pentose sugars (glucose, arabinose, ramnose and xylose) through hydrolysis using 3 types of acid catalysts, namely hydrochloric acid (HCl), sulfuric acid (H2SO4) and nitric acid (HNO3). Fermentation was carried out with S. cerevisiae concentration variation of 6; 8; 10; 12 % (v/v) and fermentation time variation of 3; 5; 7; 9 days and a pH variation of 4; 4.5; 5; 5.5 at a temperature of 30 °C. Reducing sugar characterization used the Dinitrosalicylic acid (DNS) reagent, sample surface texture analysis was carried out using Scanning Electron Microscopy (SEM) and ethanol characterization used Gas Chromatography-Flame Ionization Detector (GC-FID). The results of surface texture analysis before and after hydrolysis experienced significant changes. Optimal conditions for hydrolysis of Ulva reticulata seaweed using sulfuric acid (H2SO4) combined with a CEM synthesizer at an acid concentration of 3 % (v/v) with irradiation power of 200 watts for 50 min at a temperature of 150 °C, produced reducing sugar of 97.06 g/L. The results of GC-FID analysis indicated that bioethanol concentration obtained at optimal conditions of pH 4.5 was 42.32 %, S. cerevisiae concentration was 12 % with a bioethanol content of 42.53 % at a fermentation time of 5 days. This research is expected to provide information for researchers and industry to overcome world energy problems and environmental pollution through Ulva reticulata waste. HIGHLIGHTS The results of surface texture analysis before and after hydrolysis experienced significant changes. Optimum conditions for hydrolysis of Ulva reticulata seaweed using sulfuric acid (H2SO4) combined with a CEM synthesizer at an acid concentration of 3 % (v/v) with irradiation power of 200 watts for 50 min at a temperature of 150 °C, producing reducing sugar of 97.06 g /L. GRAPHICAL ABSTRACT

A novel anti-candidiasis cream formulation based on Melissa officinalis and Lavandula stoechas essential oils synergism

Candida albicans is the yeast strain that causes candidiasis, which can vary from minor skin and soft tissue infections to potentially fatal infections like candidemia, which can get worse due to drug resistance. Natural substances could be used as antifungal agents’ alternatives, especially against C. albicans. Thereby, the main objective of this research was to define the chemical content and evaluate the bioactivity of Melissa officinalis and Lavandula stoechas essential oils (EOs). Additionally, the synergistic effect of both oils was carried out against C. albicans, in order to formulate EOs combination-based creams. Their chemical compositions were analyzed using the combination of gas chromatography-flame ionization detector (GC-FID) and GC-mass spectrometry (GC-MS). The interaction with both EOs was also evaluated and analyzed by GC-FID and GC-MS, and the development of anti-candidiasis formulations was tested in vitro. Our results showed that the main compounds of M. officinalis EO (MOEO) were geranial (35.7%) and neral (24.1%), whereas, 1.8-cineole (61.9%) was dominant in Lavandula stoechas essential oil (LSEO) and the main compounds of the combination between both EOs were 1,8-cineole and geranial. Moreover, the MOEO exhibited substantial antifungal action against all tested microorganisms with MIC values ranging from 0.125 to 0.0019. This EO also showed synergistic effect when combined with that of L. stoechas. These findings, suggest the good bioactive qualities of the topical creams developed against C. albicans, revealing their potential to be possibly applied as an antifungal agent in industrial pharmaceutics.

Development and Validation of a GC-FID Method for the Quantitation of Δ 8-Tetrahydrocannabinol and Impurities Found in Synthetic Δ 8-Tetrahydrocannabinol and Vaping Products.

Concerns about health hazards associated with the consumption of trans-delta-8-tetrahydrocannabinol products were highlighted in public health advisories from the U. S. Food and Drug Administration and U. S. Centers for Disease Control and Prevention. Simple and rapid quantitative methods to determine trans-delta-8-tetrahydrocannabinol impurities are vital to analyze such products. In this study, a gas chromatography-flame ionization detection method was developed and validated for the determination of delta-8-tetrahydrocannabinol and some of its impurities (recently published) found in synthesized trans-delta-8-tetrahydrocannabinol raw material and included olivetol, cannabicitran, Δ 8-cis-iso-tetrahydrocannabinol, Δ 4-iso-tetrahydrocannabinol, iso-tetrahydrocannabifuran, cannabidiol, Δ 4,8-iso-tetrahydrocannabinol, Δ 8-iso-tetrahydrocannabinol, 4,8-epoxy-iso-tetrahydrocannabinol, trans-Δ 9-tetrahydrocannabinol, 8-hydroxy-iso-THC, 9α-hydroxyhexahydrocannabinol, and 9β-hydroxyhexahydrocannabinol. Validation of the method was assessed according to the International Council for Harmonization guidelines and confirmed linearity with R2 ≥ 0.99 for all the target analytes. The limit of detection and limit of quantitation were 1.5 and 5 µg/mL, respectively, except for olivetol, which had a limit of detection of 3 µg/mL and a limit of quantitation of 10 µg/mL. Method precision was calculated as % relative standard deviation and the values were less than 8.4 and 9.9% for the intraday precision and inter-day precision, respectively. The accuracy ranged from 85 to 118%. The method was then applied to the analysis of 21 commercially marketed vaping products claiming to contain delta-8-tetrahydrocannabinol. The products analyzed by this method have various levels of these impurities, with all products far exceeding the 0.3% of trans-Δ 9-tetrahydrocannabinol limit for hemp under the Agriculture Improvement Act of 2018. The developed gas chromatography-flame ionization detection method can be an important tool for monitoring delta-8-tetrahydrocannabinol impurities in commercial products.

Synthesis of the magnetic composite of Ni-MOF-I in aqueous medium and its application in magnetic dispersive micro solid phase extraction of plasticizers from pharmaceutical samples

For the first time, this research presents the synthesis procedure and analytical application of Ni-MOF-I magnetic composite. The synthesis method was green and done in an aqueous medium. The composite was employed as an adsorbent in a magnetic dispersive solid phase extraction process followed by dispersive liquid–liquid microextraction for the extraction and preconcentration of some plasticizers from pharmaceutical samples stored in plastic containers. The Ni-MOF-I magnetic composite was characterized by applying Fourier transform infrared spectrophotometry, vibrating sample magnetometry, scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction, and nitrogen adsorption/desorption analyses. For operating the extraction procedure, initially, the plasticizers were adsorbed onto the adsorbent particles by vortexing. Then, the plasticizers were desorbed from the adsorbent surface using a mL volume of 2-proponal. Subsequently, the obtained eluate phase was mixed with a mixture of 1,2-dibromoethane and 1,1,2-trichloroethane and then injected into deionized water using a glass syringe. Afterward, centrifugation was done to isolate the extractant from the aqueous phase. Eventually, one microliter of the sedimented phase was injected into gas chromatography-flame ionization detection. Acceptable analytical results such as high enrichment factors (355–415) and extraction recoveries (71–83 %), low limits of quantification (0.76–1.08 μg L−1) and detection (0.23–0.33 μg L−1), wide linear ranges (1.08–300 μg L−1), and satisfactory relative standard deviation values of 4.0–6.3 % (intra-day precision, n = 5) and 4.9–7.4 % (inter-day precision, n = 5) were achieved. The suggested procedure was used as a productive analytical method based on the Ni-MOF-I magnetic composite for the extraction and determination of some plasticizers from different pharmaceutical samples filled in plastic containers. Elimination of centrifugation, using 2-propanol as a green desorption/disperser solvent, detection of di-(2-ethylhexyl) phthalate in boric acid alcohol drop, and applying µL-level of the extraction solvent are the advantages of this proposed method.

Impact of artisanal refining activities on bacterial diversity in a Niger Delta fallow land

Hydrocarbon pollution is a major ecological problem facing oil-producing countries, especially in the Niger Delta region of Nigeria. In this study, a site that had been previously polluted by artisanal refining activity was investigated using 16S rRNA Illumina high-throughput sequencing technology and bioinformatics tools. These were used to investigate the bacterial diversity in soil with varying degrees of contamination, determined with a gas chromatography-flame ionization detector (GC-FID). Soil samples were collected from a heavily polluted (HP), mildly polluted (MP), and unpolluted (control sample, CS) portion of the study site. DNA was extracted using the Zymo Research (ZR) Fungi/Bacteria DNA MiniPrep kit, followed by PCR amplification and agarose gel electrophoresis. The microbiome was characterized based on the V3 and V4 hypervariable regions of the 16S rRNA gene. QIIME (Quantitative Insights Into Microbial Ecology) 2 software was used to analyse the sequence data. The final data set covered 20,640 demultiplexed high-quality reads and a total of 160 filtered bacterial OTUs. Proteobacteria dominated samples HP and CS, while Actinobacteria dominated sample MP. Denitratisoma, Pseudorhodoplanes, and Spirilospora were the leading genera in samples HP, CS, and MP respectively. Diversity analysis indicated that CS [with 25.98 ppm of total petroleum hydrocarbon (TPH)] is more diverse than HP (with 490,630 ppm of TPH) and MP (with 5398 ppm of TPH). A functional prediction study revealed that six functional modules dominated the dataset, with metabolism covering up to 70%, and 11 metabolic pathways. This study demonstrates that a higher hydrocarbon concentration in soil adversely impacts microbial diversity, creating a narrow bacterial diversity dominated by hydrocarbon-degrading species, in addition to the obvious land and ecosystem degradation caused by artisanal refining activities. Overall, the artisanal refining business is significantly driving ecosystem services losses in the Niger Delta, which calls for urgent intervention, with focus on bioremediation.

Changing from lipoprotein apheresis to evolocumab treatment lowers circulating levels of arachidonic acid and oxylipins

Background and aimsPrevious studies have shown that lipoprotein apheresis can modify the plasma lipidome and pro-inflammatory and pro-thrombotic lipid mediators. This has not been examined for treatment with protein convertase subtilisin/kexin type 9 inhibitors such as evolocumab, which are increasingly used instead of lipoprotein apheresis in treatment-resistant familial hypercholesterolemia. The aim of this study was to compare the effects of evolocumab treatment and lipoprotein apheresis on the fatty acid profile and on formation of lipid mediators in blood samples. MethodsWe analyzed blood samples from 37 patients receiving either lipoprotein apheresis or evolocumab treatment as part of a previous study. Patients were stratified according to receiving lipoprotein apheresis (n = 19) and evolocumab treatment (n = 18). Serum fatty acid analysis was performed using gas chromatography flame ionization detection and plasma oxylipin analysis was done using liquid chromatography tandem mass spectrometry. ResultsChanging from lipoprotein apheresis to evolocumab treatment led to lower levels of omega-6 polyunsaturated fatty acid (n-6 PUFA) including arachidonic acid, dihomo-γ-linolenic acid and linoleic acid. Moreover, several n-6 PUFA-derived oxylipins were reduced after evolocumab treatment. ConclusionsGiven that arachidonic acid, either directly or as a precursor, is associated with the development of inflammation and atherosclerosis, evolocumab-mediated reductions of arachidonic acid and its metabolites might have an additional beneficial effect to lower cardiovascular risk.