Gas Chromatography-flame Ionization Detector Research Articles

Separation and quantification of diazinon in water samples using liquid-phase microextraction-based effervescent tablet-assisted switchable solvent method coupled to gas chromatography-flame ionization detection.

This study used a liquid-phase microextraction-based effervescent tablet-assisted switchable solvent method coupled to gas chromatography-flame ionization detection as an eco-efficient, convenient-to-use, cost-effective, sensitive, rapid, and efficient method for extracting, preconcentrating, and quantifying trace amounts of diazinon in river water samples. As a switchable solvent, triethylamine (TEA) was used. In situ generation of CO2 using effervescent tablet containing Na2 CO3 and citric acid changed the hydrophobic TEA to the hydrophilic protonated triethylamine carbonate (P-TEA-C). CO2 removal from the specimen solution using NaOH caused P-TEA-C to be converted into TEA and led to phase separation, during which diazinon was extracted into the TEA phase. The salting-out process was helpful in enhancing extraction efficiency. In addition, a number of significant parameters that affect extraction recovery were examined. Under optimum conditions, the limit of detection and limit of quantitation were 0.06 and 0.2ng/ml, respectively. The extraction recovery percentage and pre-concentration factor were obtained at 95 and 190%, respectively, and the precision (inter- and intra-day, relative standard deviation %, n= 5) was <5%.

Online detection of alkanes by a biological-phase microextraction and biosensing (BPME-BS) device

Oil spill incidents occur frequently and threaten ecosystems and human health. Solid-phase microextraction allows direct alkane extraction from environmental matrices to improve the limit of detection but is unable to measure alkanes on site. A biological-phase microextraction and biosensing (BPME-BS) device was developed by immobilising an alkane chemotactic Acinetobacter bioreporter ADPWH_alk in agarose gel to achieve online alkane quantification with the aid of a photomultiplier. The BPME-BS device had a high enrichment factor (average 7.07) and a satisfactory limit of detection (0.075 mg/L) for alkanes. The quantification range was 0.1–100 mg/L, comparable to a gas chromatography flame ionisation detector and better than a bioreporter without immobilisation. ADPWH_alk cells in the BPME-BS device maintained good sensitivity under a wide range of environmental conditions, including pH (4.0–9.0), temperature (20–40 °C), and salinity (0.0–3.0%), and its response remained stable within 30 days at 4 °C. In a 7-day continual measurement, the BPME-BS device successfully visualised the dynamic concentration of alkanes, and a 7-day field test successfully captured an oil spill event, helping in source apportionment and on-scene law enforcement. Our work proved that the BPME-BS device is a powerful tool for online alkane measurement, showing substantial potential for fast detection and rapid response to oil spills on site and in situ.

Influence of Tobacco Variety and Curing on Free Radical Production in Cigarette Smoke.

Cigarette smoke contains highly reactive free radicals thought to play an important role in tobacco smoke-induced harm. Previously, large variations in free radical and toxicant output have been observed in commercial cigarettes. These variations are likely because of cigarette design features (paper, filter, and additives), tobacco variety (burley, bright, oriental, etc.), and tobacco curing methods (air, sun, flue, and fire). Previous reports show that tobacco varieties and curing methods influence the production of tobacco smoke constituents like the tobacco-specific carcinogen nicotine-derived nitrosamine ketone (NNK). We evaluated free radical, nicotine, and NNK production in cigarette smoke from cigarettes produced with 15 different types of tobacco. Gas-phase free radicals were captured by spin trapping with N-tert-butyl-α-phenylnitrone and particulate-phase radicals were captured on a Cambridge Filter pad (CFP). Both types of radicals were analyzed using electron paramagnetic resonance spectroscopy. Nicotine and NNK were extracted from the CFP and analyzed by gas chromatography flame ionization detection and liquid chromatography-mass spectrometry, respectively. Gas-phase radicals varied nearly 8-fold among tobacco types with Saint James Perique tobacco producing the highest levels (42 ± 7 nmol/g) and Canadian Virginia tobacco-producing the lowest levels (5 ± 2 nmol/g). Nicotine and NNK levels in smoke varied 14-fold and 192-fold, respectively, by type. Gas-phase free radicals were highly correlated with NNK levels (r = 0.92, p < .0001) and appeared to be most impacted by tobacco curing method. Altogether, these data suggest that tobacco types used in cigarette production may serve as a target for regulation to reduce harm from cigarette smoking. Variations in cigarette free radical and NNK levels vary based on the tobacco variety and curing method. Reducing the ratio of high-producing free radical and NNK tobacco types offer a potential tool for regulators and producers looking to reduce toxicant output from cigarettes.

Application of Nanocube-Functionalized Nitrogen-Doped Melamine Sponge for Dispersive Micro-Solid Phase Extraction (SPE) of Phenolic Compounds From Aquatic Media

A procedure is reported for the efficient extraction and determination of phenolics from aqueous media. The approach is based on the dispersive micro-solid phase extraction using synthesized Co3O4 nanocube-functionalized nitrogen-doped melamine foam. The adsorption and desorption conditions were optimized by response surface methodology and one-variable-at-a-time approaches. The proposed method was fully validated. Under the optimized conditions, the limits of detection were lower than 0.5 ng mL−1. Calibration curves were linear in the range from 1.0 to 250.0 ng mL−1, 0.7 to 200.0 ng mL−1, 0.2 to 250.0 ng mL−1, and 1.0 to 250.0 ng mL−1 for phenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol, respectively. Enrichment factors and absolute recoveries from 17.5 to 20.7 and 70% to 83% were achieved. The method was successfully applied for trace monitoring of the analytes in environmental and industrial water samples with gas chromatography—flame ionization detection analysis. Satisfactory relative recoveries between 89.0% and 105.8% were obtained along with acceptable precision below 8.1%. This method is a simple, rapid, sensitive, and reliable protocol for efficient screening of the phenolics.

Enhanced Bioactivity of Rosemary, Sage, Lavender, and Chamomile Essential Oils by Fractionation, Combination, and Emulsification.

This study aimed to increase the bioactivity of essential oils by fractionation, combination, and emulsification. In this regard, pharmaceutical quality Rosmarinus officinalis L. (rosemary), Salvia sclarea L. (clary sage), Lavandula latifolia Medik. (spike lavender), and Matricaria chamomilla L. (chamomile) essential oils were fractionated by vacuum-column chromatography. The main components of the essential oils were verified, and their fractions were characterized by thin layer chromatography, gas chromatography-flame ionization detector, and gas chromatography/mass spectrometry. Besides, oil-in-water (O/W) emulsions of essential oils and diethyl ether fractions were obtained by the self-emulsification method, followed by droplet size, polydispersity index, and zeta potential value measurements. The in vitro antibacterial effects of the emulsions and binary combinations (10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, v:v) against Staphylococcus aureus were determined by microdilution. In addition, the in vitro anti-biofilm, antioxidant, and anti-inflammatory effects of emulsion formulations were evaluated. According to the experimental results, fractionation and emulsification enhanced essential oil in vitro antibacterial, anti-inflammatory, and antioxidant effects due to increased solubility and nano-sized droplets. Among 22 different emulsion combinations, 1584 test concentrations resulted in 21 cases of synergistic effects. The mechanism of the increase in biological activities was hypothesized to be higher solubility and stability of the essential oil fractions. Food and pharmaceutical industries may benefit from the procedure proposed in this study.

Monoterpene Composition of Phloem of Eastern Larch (Larix laricina (Du Roi) K. Koch) in the Great Lakes Region: With What Must the Eastern Larch Beetle (Dendroctonus simplex LeConte) Contend?

The eastern larch beetle (Dendroctonus simplex LeConte) is the only tree-killing bark beetle that colonizes tamarack, or eastern larch, (Larix laricina (Du Roi) K. Koch) in the Great Lakes region. Historically, outbreaks have been intermittent and of short duration, frequently following predisposing factors such as drought or defoliation. However, over the past two decades, this insect has been in a perpetual state of outbreak in parts of the U.S. Great Lakes region, a deviation from historic norms. From 2001–2021, the insect impacted 300,000 ha, or 60% of the tamarack forests in Minnesota. This activity has prompted renewed interest in the beetle’s chemical ecology, including aspects of host semiochemistry. While foliar chemistry has been well documented in L. laricina, characterization of the monoterpene composition of the phloem has been lacking. We collected phloem samples from 56 tamarack trees across 14 locations in Wisconsin and Minnesota and assessed the relative abundances of the major monoterpenes present using gas chromatography-flame ionization detector (GC-FID). Individual terpenoid components identified included α-pinene (39.4%) and ∆-3-carene (30.0%) followed by several other components in small (&lt;8%) amounts. This knowledge provides a basis for future testing of monoterpene synergists or antagonists in pheromone lures targeting eastern larch beetle and/or its natural enemies.

Towards high-throughput screening (HTS) of polyhydroxyalkanoate (PHA) production via Fourier transform infrared (FTIR) spectroscopy of Halomonas sp. R5-57 and Pseudomonas sp. MR4-99.

High-throughput screening (HTS) methods for characterization of microbial production of polyhydroxyalkanoates (PHA) are currently under investigated, despite the advent of such systems in related fields. In this study, phenotypic microarray by Biolog PM1 screening of Halomonas sp. R5-57 and Pseudomonas sp. MR4-99 identified 49 and 54 carbon substrates to be metabolized by these bacteria, respectively. Growth on 15 (Halomonas sp. R5-57) and 14 (Pseudomonas sp. MR4-99) carbon substrates was subsequently characterized in 96-well plates using medium with low nitrogen concentration. Bacterial cells were then harvested and analyzed for putative PHA production using two different Fourier transform infrared spectroscopy (FTIR) systems. The FTIR spectra obtained from both strains contained carbonyl-ester peaks indicative of PHA production. Strain specific differences in the carbonyl-ester peak wavenumber indicated that the PHA side chain configuration differed between the two strains. Confirmation of short chain length PHA (scl-PHA) accumulation in Halomonas sp. R5-57 and medium chain length PHA (mcl-PHA) in Pseudomonas sp. MR4-99 was done using Gas Chromatography-Flame Ionization Detector (GC-FID) analysis after upscaling to 50 mL cultures supplemented with glycerol and gluconate. The strain specific PHA side chain configurations were also found in FTIR spectra of the 50 mL cultures. This supports the hypothesis that PHA was also produced in the cells cultivated in 96-well plates, and that the HTS approach is suitable for analysis of PHA production in bacteria. However, the carbonyl-ester peaks detected by FTIR are only indicative of PHA production in the small-scale cultures, and appropriate calibration and prediction models based on combining FTIR and GC-FID data needs to be developed and optimized by performing more extensive screenings and multivariate analyses.

Geochemical characterisation of the Turonian-Maastrichtian bituminous sands in Dahomey Basin, Southwestern Nigeria

The Turonian-Maastrichtian bituminous sands resource in the Dahomey (Benin) Basin, Southwestern Nigeria, is a potentially economically viable hydrocarbon reserve, which has recently attracted renewed attention. An integrated study involving the use of elemental composition, and geochemical analyses (gas chromatography flame ionisation detector (GC-FID), Fourier transform infrared (FTIR), and gas chromatography mass spectrometry (GC-MS)) were carried out to provide an improved understanding of this resource using geochemical signatures and evaluate the n-alkane distribution of bituminous sands to determine its aliphatic hydrocarbon distribution and the prevailing depositional conditions. Elemental composition shows the dominance of carbon ( Av. 79.8%). The atomic ratios of H/C and O/C, respectively, range from 0.05 to 0.11, and 0.04 to 0.08. SiO2 is the dominant oxide, with concentrations ranging between 73.15 and 80.50 wt. %, while Zn is the dominant trace element. Twenty-three aliphatic hydrocarbons: C10, C13, C15, C17–C37, were identified on GC-FID, with distribution showing predominance of long-chain n-aliphatics, with a Carbon Preference Index (CPI) value range of 1.01 to 1.02. A bimodal n-alkane fingerprint envelope is visible on GC, with maxima between nC16– nC18 and nC27, indicating varied contributions from both terrigenous and non-terrigenous (possibly marine algae) organic matter. Despite the biodegradation of n-alkanes, GC-MS chromatograms (m/z 256) show evidence of bicyclic sesquiterpenes (BSs) in the bituminous sands investigated. Infrared (IR) spectra show the dominance of the hydroxyl functional group, while 2922.2cm-1 and 2855.1cm−1 are common in all the samples, revealing the presence of residual organics. This study revealed that the bituminous sands are highly waxy in nature and derived from higher plants of both marine and terrestrial source input with more influence from land-dwelling biogenic sources under oxic conditions.

Antiproliferative activity from five Myrtaceae essential oils

The Myrtaceae plants are cultivated for their edible fruits and folk medicinal uses. Likewise, their leaves, flowers, and fruit essential oils (EOs) are described to have antiproliferative, antimicrobial, and antioxidant activities. This work analyzed the chemical compositions and evaluated the antiproliferative activities of essential oils (EO) of Myrcia bella Cambess, Myrcia fallax (Rich.) DC., Myrcia guianensis (Aubl.) DC., Eugenia aurata O. Berg, and Eugenia punicifolia (Kunth) DC, from the Brazilian Cerrado. EOs were obtained by leaf hydrodistillation and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) plus Gas Chromatography-Flame Ionization Detector (GC-FID). The major component in M. bella was α-cadinol (14.4%); in Myrcia fallax (Rich.) DC., guaiol acetate (14.4%); and in M.guianensis, (E)-iso-g‑bisabolene (17.5%). For E. aurata and E. punicifolia, bicyclogermacrene (25.3%) and (E)-caryophyllene (18%), respectively, were the most relevant chemical constituents. The EOs were tested against the human tumor cell lines UACC-62 (melanoma), MCF7 (breast), 786-0 (kidney), NCI-H460 (lung), OVCAR-3 (ovarian), HT29 (colon), and K562 (leukemia) and one non-tumor cell line (VERO). Eugenia aurata presented the most promising effect against HT29 (TGI = 1.5 mg/mL), K562 (TGI = 5.0 mg/mL), and no toxicity against non-tumor VERO cells (TGI&gt; 250 mg/mL). For the other EOs, moderate to no activity was observed. So, in conclusion, E. aurata EOs revealed a good potential for anticancer applications.

Black Pine (Pinus nigra) Essential Oil as a Green Corrosion Inhibitor for Carbon Steel

In this work, the essential oil of black pine (Pinus nigra J. F. Arnold) was used for the first time as a natural, ecological, and sustainable corrosion inhibitor for the acid cleaning of carbon steel. The essential oil was extracted by hydrodistillation using a Clevenger-type apparatus, and the oil was analyzed by gas chromatography–flame–ionization detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). The most abundant components in the essential oil were α-pinene, germacrene D, (E)-cariophyllene, and β-pinene. The inhibition efficiency was determined by electrochemical methods (electrochemical impedance spectroscopy and potentiodynamic polarization measurements). The results showed that the inhibitory efficiency of the black pine essential oil increases with time, reaching the highest values after 4 h of immersion for all inhibitor concentrations. It was also shown that black pine essential oil is a mixed-type inhibitor. The contact angle measurements confirmed that the black pine essential oil, as a new natural, environmentally safe inhibitor, is able to protect carbon steel from corrosion in a 1 M HCl solution.

Clouding of intraocular silicone oil in the absence of emulsification.

To describe intraocular clouding of silicone oil in the absence of emulsification. Retrospective observational case series of patients who received silicone oil injections and developed silicone oil discoloration without emulsification after pars plana vitrectomy. Clinical examinations and physicochemical analyses were performed to find out the common cause for the opaque oil. Thirteen patients developed silicone oil discoloration after pars plana vitrectomy. It could be traced down that all patients had received silicone oil from one respective production batch. The silicone oil was removed as soon as possible after the changes were detected (range, 8-16 weeks). Gas chromatography flame ionization detector (GC-FIC), size exclusion chromatography (SEC) and high performance liquid chromatography (HPLC) analysis showed the absence of small molecular weight compounds in the opaque lot. Thermogravimetric analysis (TGA) revealed the opaque lot was more temperature stable. During the follow-ups, no obvious retinal toxicity could be observed and best recorded visual acuity improved considerably in twelve patients and was only limited by the underlying retinal pathology. This is the first report on opacification of intraocular silicone oil without emulsification. This discoloration of silicone oil may disturb vision and prevent proper fundus examination, however, seems to be a non-toxic phenomenon without serious long-term consequences.

Key odorant identification and odor treatment technology evaluation during the chemical synthesis process of typical pesticide

Odor pollution has become one of the important environmental problems in China. In this study, Gas Chromatography Ion Mobility Spectrometry (GC-IMS), Gas Chromatography Mass Spectrometer (GC-MS) and Flame Ionization Detector (FID) were combined to obtain comprehensive information of the odor produced during the production of Captan, a common pesticide, and to evaluate the efficiency of the odorant treatment techniques utilized by the manufacturer studied. Based on our findings, refining, an important phase during the production process of Captan, was found to be the most important factor in determining the type and the concentration of the odorant produced. Of the odorants found during the production process, perchloromethylmercaptan (CCl3SCl) and other chlorine-containing compounds are the key odorants during the production process based on the calculation of odor activity value (OAV). The current odorant treatment utilized by the manufacturer studied showed about 40 % removal rate. However, the odorant treatment produced a new odorant, dimethyl disulfide. Therefore, a much more targeted odorant treatment technique without the production of new odorants is desired and should be utilized.

Sodium nitrite poisoning: A series of 20 fatalities in which post-mortem blood nitrite and nitrate concentrations are reported

Sodium nitrite has several industrial applications however its accidental or intentional ingestion has been associated with severe toxicity and death. We present a series of 20 cases over 2 years in which evidence of sodium nitrite ingestion was found at the scene and supported by biochemical analysis of post-mortem blood nitrite and nitrate levels. Routine toxicological screening was performed on post-mortem blood samples received at University Hospitals of Leicester (UHL) NHS Trust, including ethanol analysis by headspace gas chromatography–flame ionisation detection (HS GC-FID), drug screening by high resolution accurate mass–mass spectrometry (HRAM-MS) and confirmatory drug quantitation by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cases in which the history indicated the possibility of nitrite salts present at the scene, purchase of a suicide kit or a dusky-ash appearance of skin on post-mortem were referred to a specialist laboratory for nitrite and nitrate analysis. Analysis was based upon the gas-phase chemiluminescent reaction between nitric oxide (NO) and ozone; NO levels were determined using an NOA 280A, Sievers NO analyser. Twenty post-mortem cases in which sodium nitrite ingestion was the most probable cause of death were reported between January 2020 and February 2022; mean age was 31 years (range 14–49) with 9/20 (45%) female. 16/20 (80%) of cases had a history of depression and / or mental health issues. In half of the cases, anti-depressant / anti-psychotic drugs were prescribed; these drugs were detected in 8/20 (40%) cases. Ethanol was detected in 4/20 (20%) cases and anti-emetic drugs in 7/20 (35%) cases; anti-emetic drugs may be used to aid retention of sodium nitrite. Illicit drugs (amphetamine, cannabis and cocaine) were present in 3/20 cases (15%). Nitrite was found to be elevated in all but one case (95%), and nitrate was elevated in 17/20 (85%) cases. This paper highlights a surge in numbers of deaths across England and Wales due to sodium nitrite toxicity. Although, nitrite poisoning remains a rare cause of death, it is worthwhile considering its use in individuals with suicidal ideation given its unregulated availability online. The detection and quantitation of nitrite and nitrate requires specialised, highly reliable methodology currently only available in research laboratories. Implication of sodium nitrite ingestion also relies heavily upon circumstantial evidence combined with quantification. The provision of a quantitative nitrite / nitrate analytical service greatly assists in determining the cause of death in these cases.

In situ formation of deep eutectic solvents based dispersive liquid–liquid microextraction for the enrichment of trace phthalate esters in aqueous samples

In this work, several new in situ deep eutectic solvents (DESs) were prepared with two low toxic phenols thymol and p-cresol as hydrogen bond donors (HBDs) and three biodegradable esters 3-hydroxyhexanoate, butyl lactate and methyl salicylate as hydrogen bond acceptors (HBAs), and the in situ formation of DESs could be achieved at room temperature. Based on the in situ formation of DESs, a dispersive liquid–liquid microextraction (DLLME) method was developed to enrich four phthalate esters (PAEs) from water and beverage samples combined with gas chromatography-flame ionization detection (GC-FID). After the most appropriate type of DES was determined, the influencing factors of the in situ DES-based DLLME procedure were explored and optimized by Design of experiment (DoE). The optimized in situ DES-based DLLME approach exhibited good linearity in the range of 1–800 µg/L with determination coefficient (R2) from 0.9936 to 0.9983, limits of detection (LODs) within 0.5–2 μg/L, enrichment factors (EFs) from 256.3 to 467.1 and extraction recoveries (ERs) of 51.26 %-93.42 %. Finally, the proposed method was successfully applied for the determination of PAEs in water and beverage samples contacted with plastics, and good practical applicability was presented with the spiked recoveries of 76.17 %-118.09 %.

Valorization of Lyophilized Olive Mill Wastewater: Chemical and Biochemical Approaches

Lipid composition and antioxidant activity have been carried out in order to valorize the composition of olive mill wastewater extracts with different solvents (supercritical carbon dioxide, n-hexane, dichloromethane and ethanol). The antioxidant activity was evaluated using ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests. The total phenolics and flavonoid contents were, also, determined. The chemical composition of the extracted oil was established, respectively, by gas chromatography–flame ionization detector and high-performance liquid chromatography methods. The results showed that the oleic acid and equivalent carbon number of forty-eight were the major compounds of the analyzed oils. Residual olive mill wastewater from the Sousse region displayed the highest DPPH radical-scavenging activity (31.10 ± 0.10 μg/mL). The chemical analysis of extracts of OMWs showed that the n-hexane fraction contained an abundance of oleic acid (61.62%) and an equivalent carbon number of forty-eight (53.14%). The best antioxidant activity was determined for the ethanol fraction (14.5 μg/mL). The final results showed a significant difference and variations in polar and apolar components. Moreover, n-hexane extracts showed high percentages of Monounsaturated fatty acids (MUFA) with 64% of OMWs oil composition and the dichloromethane extracts contained the largest amount of flavonoids (160.30 ± 1.70 mg EQ/g DM).

Minimum amount of diesel in jet fuel detected by simulated Distillation FID gas chromatography that can influence DEF STAN

Information on boiling point (BP) is a crucial metric for defining petroleum streams. Understanding the BP distribution range of hydrocarbon products is crucial for selecting an appropriate way to process feedstocks, controlling the process, identifying impurities, and developing new tests. To evaluate BP range rapidly, the refinery employs simulated distillation (SimDis) by gas chromatography (GC) paired with a flame ionization detector (FID) and a capillary column. This method is used to examine the level of contamination in petroleum products. Jet A-1 fuel is an essential product whose specifications can be altered by diesel contamination. Some producers utilize the same distribution line for both products, contaminating the Jet fuel that is shipped. We conducted research to determine the lowest level of diesel contamination in jet A-1 fuel. The study consists of varying proportions of diesel (0.5%, 2%, and 5% mass) blended with jet A-1 to determine the impact on standard specifications DEF STAN 91-91/12 and ASTM D1655. Among those methods, SimDis by GC-FID was the most successful method for identifying a little level of diesel contamination. Properties of jet fuel, such as thermal stability, water separation, and electrical conductivity, are particularly sensitive to trace contamination and can be altered by it.

Accurate quantification of TAGs to identify adulteration of edible oils by ultra-high performance liquid chromatography-quadrupole-time of flight-tandem mass spectrometry

Edible oils play important roles in biological functions, and triacylglycerols (TAGs) in edible oils are complex mixtures. This makes accurate TAGs quantitation quite difficult that bring economically motivated food adulteration. Herein, we demonstrated a strategy for accurate quantification of TAGs in edible oils, which could be applied in identification of olive oil adulteration. The results showed that the proposed strategy could significantly improve the accuracy of TAG content determination, reduce the relative error of fatty acids (FAs) content determination, and present a wider accurate quantitative range than that of gas chromatography-flame ionization detection. Most important, this strategy coupled with principal component analysis could be used to identify adulteration of high-priced olive oil with cheaper soybean oils, rapeseed oils or camellia oils at a lower concentration of 2%. These findings indicated that the proposed strategy could be regarded as a potential method for edible oils quality and authenticity analysis.

In vitro antitrichomonal activity of Satureja khuzestanica and main essential oil components carvacrol, thymol, and eugenol

Human trichomoniasis is a widespread sexually transmitted disease and the concern of drug resistance in the parasite is growing. Hence, this study was performed to evaluate in vitro antitrichomonal activity of Satureja khuzestanica, carvacrol, thymol, eugenol, and phytochemical evaluation of the S. khuzestanica oil. Extracts and essential oil of S. khuzestanica, and the components were prepared. Then, susceptibility testing was performed using the microtiter plate method and Trichomonas vaginalis isolates. The minimum lethal concentration (MLC) of the agents was determined in comparison with metronidazole. Also, the essential oil was investigated by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. After 48 hours of incubation, carvacrol and thymol were the most effective antitrichomonal agents with MLC of 100 µg/mL, followed by the essential oil and hexanic extract (MLC = 200 µg/mL), then eugenol and methanolic extract (MLC = 400 µg/mL), in comparison with the metronidazole MLC of 6.8 µg/mL. Overall, 33 identified compounds accounted for 98.72% of the total essential oil composition with carvacrol, thymol, and p-cymene being the major constituents. The results suggested the potency of S. khuzestanica and its bioactive ingredients against T. vaginalis. Thus, further in vivo studies are required to evaluate the efficacies of the agents.

In vitro efficacy of essential oils against Haematobia irritans

The horn fly (Haematobia irritans) infestation in the cattle in Brazil leads to significant economic damage for livestock. The efficacy of many essential oils has been demonstrated in the control of veterinary ectoparasites. This study aimed to evaluate the in vitro efficacy of four essential oils to adult horn fly control. The essential oil from Mesosphaerum suaveolens (L.) Kuntze (Lamiaceae) was extracted by hydro-distillation, while that the water steam distillation method was used to extract the essential oils from Varronia curassavica (Jacq.) Roem. &amp; Schult. (Boraginaceae), Alpinia zerumbet (Pers.) B.L. Burtt &amp; R.M. Sm. (Zingiberaceae) and Psidium guajava L. (Myrtaceae). Afterwards, all the essential oils were analyzed by Gas Chromatography Mass Spectrometry (GC?MS) and Flame Ionization Detector (GC-FID) for determination of their chemical composition. The bioassays in vitro were performed according to the impregnated filter paper methodology. All the essential oils evaluated in this study exhibited efficacy in vitro against H. irritans. The highest mortality of H. irritans was determined by essential oils from A. zerumbet (100%) and M. suaveolens (96.2%) at 50 mg mL-1. In concentration of 100 mg mL-1 V. curassavica and P. guajava essential oils caused the mortality of 99.2% and 82.8%, respectively. The A. zerumbet, M. suaveolens, V. curassavica and P. guajava essential oils showed in vitro efficacy against H. irritans. Further studies with associations and nanoemultions are necessary to increase the efficacy and stability of these essential oils on field conditions.

Phytochemical Screening and Quantitative Analysis of Annona muricata Leaf Ethanolic Extract by Gas Chromatography-Flame Ionization Detection (GC-FID)

Annona muricata (soursop) leaves have been traditionally used for medicinal purposes due to its potential antioxidant, anti-inflammatory, anticancer, antimicrobial, and analgesic properties. This study quantitatively determined the phytochemical composition of soursop leaf. Using a BUCK M910 Gas Chromatography with a flame ionization detector, the analysis of phytochemicals was carried out. A 15 m x 250 0.15 RESTEK MXT-1 column was used. Helium 5.0pa.s was used as the carrier gas, flowing at a rate of 40 ml/min, with a splitless injection of 2ul of sample at a linear velocity of 30cm/s. The injector temperature was 280⁰C. At first, operating at 200⁰C, the oven was then increased to 330⁰C at a rate of 3⁰C per minute, and this temperature was maintained for 5min. An operating temperature of 320⁰C was used by the detector. The result shows that soursop ethanolic extract contains phytochemicals that belong to the broad class flavonoids (a class of polyphenolic compounds). They include naringenin (5.92 ug/ml), flavan-3 ol (5.70 mg/l), rutin (2.79 ug/ml), flavanones (3.28 ug/ml), kaempferol (6.15 ug/ml), flavone (1.99 ug/ml), proanthocyanin (2.36 ug/ml). Other polyphenols (not flavonoids) present include resveratrol (7.03 ug/ml), tannin (2.90 ug/ml), catechin (2.49 ug/ml), and epicatechin (7.67 ug/g). The alkaloids found include lunamarin (4.72 ug/ml) and spartein (2.07 ug/ml) while saponins found include sapogernin (16.07 ug/ml) and sapogenin (3.08 ug/ml). Other classes of phytochemicals found include steroids, cyanogenic glycoside, anti-nutrient, and cardiac glycosides. Soursop leaf contains bioactive compounds such as flavonoids, polyphenols, alkaloids, steroids, cyanogenic glycoside and other phytochemicals with medicinal potentials.