Gas Chromatography With Flame Ionization Detection Research Articles

Degradation of High Concentrations of Anthracene Using White-Rot Wood-Inhabiting Fungi and Investigation of Enzyme Activities

Owing to the production of lignin-modifying enzymes (LMEs), white-rot fungi (WRF) such as polypores are potent organisms in the biodegradation of xenobiotic pollutants. The nonspecific function of LMEs including laccase and manganese peroxidase (MnP), has enabled the use of WRF in biotechnological applications, particularly in bioremediation. In this study, 12 strains from nine white-rot basidiomycete genera viz., Ganoderma, Inocutis, Irpex, Lentinus, Lenzites, Oxyporus, Peniophora, Sanghuangporus, and Trametes were isolated from Iran and identified using morphological and molecular tools. The enzyme activity of laccase and manganese peroxidase that directly correlated with the biodegradation were determined, and the strains with the highest enzyme activities were evaluated for their ability to degrade 400 mg/L of anthracene over 28 days. Gas chromatography with flame ionization detector (GC-FID) revealed that four polypores viz., Trametes versicolor v21te, T. versicolor v22da, T. hirsuta, and Oxyporus sp. degraded 64%, 52%, 34%, and 20% of the anthracene, respectively. According to our analysis, the examined indigenous WRF are potentially useful candidates for the development of new mycoremediation techniques to degrade polycyclic aromatic hydrocarbons (PAHs).

Solvolysis and oxidative liquefaction of the end-of-life composite wastes as an element of the circular economy assumptions

In pursuit of sustainable development, recycling composite waste is a crucial challenge as well as an opportunity to support the progress towards eco-friendly materials management and circular economy practices. The current study brings together two modern recycling techniques solvolysis and oxidative liquefaction to recycle five types of composite waste materials including wind turbine blades (WTBs), composite pipes, personal protective equipment (PPEs) used in the medical sector, photovoltaic (PV) panels and municipal solid waste (MSW). Following a well-structured experimental design for each type of waste the solvolysis was performed at a temperature range of 100–190 °C, process time within the range of 1–3 h, and catalyst (TBD) concentration within the range of 0.015–0.025 mol, end with ethylene glycol and 1-methyl-2-pyrrolidinone in a 1:1 M ratio, while depending on the material evaluated, the oxidative liquefaction process was conducted at temperatures between 250 and 350 °C for WTB and between 200 and 300 °C for PPE, MSW, and PV. Oxidant concentrations, reaction time and pressure (15–45%, 30–90 min, 20–40 bar for WTBs, 30–60%, 45 min, 30 bar for remaining waste types) were studied in addition to highly variant waste-to-liquid ratio from 5 to 25% for WTB, 3–7% for PPE and MSW, and 12.5–37.5 for PV. Prior to experimental investigation, surface morphologies and chemical studies of the waste material were performed by scanning electron microscope (SEM) and Fourier transform infrared FT-IR spectroscopy, while after experimentation total polymer degradation (TPD) was calculated and liquid products were analysed through gas chromatography with flame ionisation detection (GC-FID). Following the solvolysis, 50–60% TPD was obtained, allowing for the recovery of glass fibres (GF) with average lengths of 50–60 mm and a maximum length of 650 mm. This allowed for the recovery of GFs with average lengths of 50–60 mm and a maximum length of 650 mm. In the case of oxidative liquefaction, total polymer degradation of 72–100%, 52–100% and 55–100% was achieved, depending on the investigated waste, i.e. WTB, PPE and MSW, respectively. The yield of oxygenated chemical compounds depended upon the types and composition of waste, but acetic acid was the main acid while WTB, PPE, and MSW, the liquid samples contained phenol also. Involved chemistry and possible degradation pathways of complex composite wastes are discussed in detail to enhance the recycling process and material recovery.

Chemometrics Evaluation of Lemongrass Essential Oils: Authenticity, Quality and Selection Of Bioactives against t. cruzi.

AbstractThe effectiveness of treatments against the parasite Trypanosoma cruzi, the causative agent of Chagas disease, is limited in the chronic phase of the disease. The essential oils of lemongrass (Cymbopogon citratus and Cymbopogon flexuosus) have shown activity against this parasite. This study aimed to use principal component analysis (PCA) to analyze the data of lemongrass essential oils submitted to gas chromatography with flame ionization detector (GC‐FID) and proton nuclear magnetic resonance (1H NMR) as well as partial least squares (PLS) regressions to correlate chemical variability with the results of biological assays. The PLS models highlighted geraniol, caryophyllene, and limonene as the main compounds responsible for antioxidant activity. Regarding cytotoxicity, the PLS models indicated that this activity is a cumulative effect of multiple compounds. For the trypanocidal effect, median lethal concentration (CL50) values ranged from 15.12 ± 3.96 to 110.10 ± 11.22 μg mL−1, resulting in selectivity index (SI) values of 2.99 to 22.55 times more selective for T. cruzi compared to host cells. PLS indicated that geraniol, neral and geranial were the main contributors to the trypanocidal effect, suggesting the potential for somatic or synergistic effects against trypomastigote forms.

Evaluation of spectroscopic techniques for on-site drug testing of festival seizures.

Despite the fact that drugs of abuse are illegal, a drug-free festival still remains an utopia in most settings. For law enforcement purposes, it is necessary to rapidly determine whether controlled substances are involved. On-site testing is a challenging task because drugs appear in different physical forms and concentrations. The aim of this study was to compare the performance of two spectroscopic techniques, Raman and Fourier transform-infrared (FT-IR), for the testing of drug seizures at a dance festival. First, samples were measured through packaging with Raman. Subsequently, homogenized samples were analysed with FT-IR. For MDMA tablets, a chemometric model was applied on the FT-IR spectra for the dose estimation. After the festival, results were confirmed in the forensic laboratory with gas chromatography coupled with mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). In total, 166 samples of which 90 tablets, 53 powders, 16 crystals and 7 liquids were analysed. MDMA, cocaine and ketamine were the top three drugs seized. The Raman technique was suitable for powders and crystals (sensitivity of 100% and 81%, respectively). However, in comparison with FT-IR, Raman performance was lower for the analysis of liquids (sensitivity of 67%) and 'ecstasy'-like tablets (sensitivity of 41%). Overall, sensitivities above 95% were obtained with FT-IR. The MDMA doses of the tablets, determined on-site, ranged between 52 mg and 336 mg MDMA hydrochloride. For a quick identification of a variety of drugs on-site, the combination of Raman and FT-IR is recommended. It should be emphasized that optimized settings, in-house libraries and analysis by trained operators are essential to obtain correct results.

Phytochemical analysis and effect of short-term administration of aqueous seed extract of Aframomum melegueta on haematologic indices of female albino rats

Background and aims: Aframomum melegueta (Alligator pepper) is a dietary spice widely used for entertainment, religious rites, food flavor enhancer, possessing erythropoietic potentials, and many other medicinal uses. Women are included in eating this widely used spice. This experiment determined the health risk or benefit of short-term administration of aqueous seed extract of A. melegueta on haematologic indices of female albino rats. Methods: Thirty adult female albino rats weighing 160 to 200 g were used for the study. Male rats were introduced into the female rat cages of groups II-V within 12h at the expected estrous phase for mating and withdrawn afterward. Groups I, II, and III were orally administered distilled water only, while groups IV and V received oral doses of 5 µg/kg b.w. Cabergoline and 3000 mg/kg b.w. aqueous seed extract of A. melegueta respectively 24 hours postpartum and once daily by oral gavage for three days. Results: Fourier-transform infrared spectroscopy (FTIR) identified twelve functional groups in the seed extracts, namely –OH, -NH2 , CH, -NH3 +, -CH3 , -OH, -N=C=O, -C≡N, -C=C=C, -NH, -CH3 and -1,3,5-trisubstituted benzenes, while gas chromatography with flame ionization detector (GCFID) determined 15 bioactive components namely kaempferol, naringenin, Sapogernin, flavanones, anthocyanin, flavan-3-ol, cyanogenic glycoside, ribalinidine, rutin, catechin, resveratrol, spartein, epicatechin, steroid and phytate. Non-significant alterations in hemoglobin, packed cell volume (PCV), and red blood cell count were observed. There was a significant (P<0.05) decrease in WBC during pregnancy, but it was improved postpartum. However, platelet count was significantly (P<0.05) reduced after extract administration. Conclusion: The results indicate no adverse anemic condition elicited during pregnancy and delivery on haematologic parameters, namely red blood cells, hemoglobin, and PCV, with a significant decrease in WBC during pregnancy as well as reduction in platelet counts (thrombocytopenia) of extract treated animals post-partum likely due to the flavonoid, resveratrol as well as rutin and (–)-epicatechin components of A. melegueta and thus may increase the risk of bleeding disorders but reflects a positive anti-atherogenic and cardioprotective effect.

Chemical composition, antioxidant and antimicrobial activities of Rumex obtusifolius L. essential oil from the highlands of Ecuador

The chemical composition, antioxidant and antimicrobial activities of the essential oil from the aerial parts of Rumex obtusifolius L. were studied. To the best of the authors’ knowledge, this essential oil has never been fully characterized. The component analysis of the essential oil was done by gas chromatography with flame ionization detector (GC-FID) and mass selective detector (GC-MS). A total of 104 compounds, representing 97.8% of the essential oil, were identified. Aliphatic compounds, mainly methyl ketones (74.2%) and monoterpene hydrocarbons (13.7%) were found to be the most abundant compounds. The major compounds were undecan-2-one (47.6%) and nonan-2-one (13.4%). The antioxidant activity of the essential oil, evaluated by DPPH (IC50 9.11 mg/mL) and ABTS (IC50 36.72 mg/mL) assays, exhibited a weak ability in scavenging radicals. The essential oil also showed a low ferric reducing activity. The essential oil exhibited very good activity against E. coli and S. aureus, but low activities against S. enterica serovar, P. aeruginosa and C. albicans. MIC values of the essential oil varied from 0.38-27.04 μL/mL, with the lowest for E. coli.

An in-depth study of the oxidative liquefaction process for polymeric waste reduction and chemical production from wind turbine blades and personal protective equipment used in the medical field

An in-depth study of the oxidative liquefaction process has been provided to degrade the polymeric waste from personal protective equipment (PPEs) and wind turbine blades (WTBs). Thermogravimetric investigations demonstrate that WTBs have three prominent peaks throughout the degradation, whereas PPEs display solitary peak features. Experiments are carried out employing specific experimental design approaches, namely the Central Composite Face-Centered Plan (CCF) for WTBs and the Central Composition Design with Fractional Factorial Design for PPEs in a batch-type reactor at temperature ranges of 250–350 °C, pressures of 20–40 bar, residence times of 30–90 min, H2O2 concentrations of 15–45 %, and waste/liquid ratios of 5–25 % for WTBs. These values were 200–300 °C, 30 bar, 45 min, 30–60 % and 5–7 % for PPE. A detailed comparison has been provided in the context of total polymer degradation (TPD) for PPE and WTBs. Liquid products from both types of wastes after the oxidative liquefaction process are subjected to gas chromatography with flame ionization detection (GC-FID) to identify the existence of oxygenated chemical compounds (OCCs). For WTBs, TPD was 20–49 % and this value was 55–96 % for PPE while the OCC yield for WTBs (36.31 g/kg - 210.59 g/kg) and PPEs (39.93 g/kg - 212.66 g/kg) was also calculated. Detailed optimization of experimental plans was carried out by performing the analysis of variance (ANOVA) and optimization goals were maximum TPD and OCCs yields against the minimum energy consumption, though a considerable amount of complex polymer waste can be reduced and high concentrations of OCC can be achieved, which could be applied for commercial and environmental benefits.

THC Content on a Dry Weight Basis: Implications for Hemp Legality.

The 2018 Farm Bill defines hemp as Cannabis sativa L. with a tetrahydrocannabinol (THC) concentration not more than 0.3% on a dry weight basis where THC is implied to be total THC (THCTotal) including both acid (Δ9-THCA) and neutral (Δ9-THC) forms. Effect of temperature and mass were studied to determine the quickest time to prepare fresh hemp suitable for grinding without affecting THCTotal. Proficiency testing program data were also analyzed to compare THCTotal contents on a dry versus wet weight basis. Fresh hemp of 150 and 400 g were freeze-dried or heat-treated at 50 °C, 60 °C, and 70 °C for various lengths of time up to 72 hours. Ground hemp was analyzed for moisture content via AOAC 934.01 and THCTotal via liquid chromatography/mass spectrometer (LC/MS) or gas chromatography with flame ionization detection (GC/FID). A data set analyzed from a proficiency testing program included moisture and THCTotal from 20 to 67 laboratories on 12 analytical samples circulated from 2020 through 2022. The quickest drying time of 24 h occurred at 70 °C with 150 g. These conditions did not affect THCTotal content on a dry weight basis. Twelve proficiency testing program analytical samples ranged from 5.8 to 11.4% moisture and 0.144 to 0.399% THCTotal on a wet weight basis. An increase in reported THCTotal on a dry weight basis compared to a wet weight basis ranged from 0.002 to 0.027% with a significant difference occurring in only one analytical sample. Suitable condition for drying hemp without altering THCTotal content was 24 h at 70 °C. Determining residual moisture in oven-dried ground hemp to calculate THCTotal content on a dry weight basis provides no benefit given minimal difference between contents on dry versus wet weight bases, interlaboratory variability, and terpene volatilization.

Chemical Composition, Antioxidant, and Cytotoxic Activity of Essential Oils in the Above-Ground Parts of Sonchus oleraceus L.

Sonchus oleraceus L. is a leafy vegetable that is usually consumed in the area of the Mediterranean and is a frequently used traditional herb to treat a variety of ailments. Previous studies deduced the potent antioxidant and cytotoxic functions of the different extracts and isolated compounds from S. oleraceus. The current study represents the first instance of chemical profiling and bioactivities of the extracted essential oil (EO) of S. oleraceus. The present investigation set out to identify the chemical components of this EO by means of Gas Chromatography with Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (G004-MS) techniques; assess the oil's antioxidant potencies through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate (ABTS) assays; and evaluate the oil's cytotoxic impact against HepG2 cancer cell lines. The GC-MS chemical profiling revealed the identification of 23 components representing 97.43% of the total oil mass within abundant cyclic ketones (20.15%), nonterpenoidial hydrocarbons (28.77%), and sesquiterpenes (42.19%). The main components were n-nonadecane (28.77%), trans-caryophyllene (23.73%), trans-methyl dihydrojasmonate (19.55%), and cis-cadina-1,4-diene (9.44%). In a dose-dependent manner, this EO demonstrated antioxidant capacities on DPPH and ABTS, with IC50 values of 609.35 and 804.16 µg/mL, respectively, compared to ascorbic acid. Using doxorubicin as a reference therapy, the MTT assay findings revealed that this oil had remarkable inhibitory effects on the proliferation of HepG2 cancer cell lines, with an IC50 of 136.02 µg/mL. More studies were recommended for further investigation of new biological roles for this oil and its main components, along with the construction of action mechanisms based on chemical components.

Rapid analysis of eucalyptus oil adulteration in Moroccan rosemary essential oil via GC-FID and mid-infrared spectroscopy

Essential Oil (EO) extracted from Rosemary is known for its therapeutic, antifungal, stimulant and antibacterial effects. This study aimed to detect and quantify the adulteration of Rosemary essential oil with different percentages of eucalyptus essential oil, using two analytical techniques: gas chromatography with Flame Ionization Detection (GC-FID) and Fourier Transform Mid-infrared spectroscopy (FT-MIR), combined with chemometric tools such as Principal Component Analysis (PCA), Partial Least Squares regression (PLS-R) and support vector regression (SVR). The use of PCA on the results obtained from GC-FID and FT-MIR indicates the possibility of categorizing the data into two distinct groups: adulterated essential oil and non-adulterated essential oil. However, it is noted that GC-FID can only detect adulteration starting from 40%, while spectroscopy is capable of detecting lower percentages of adulteration. The use of PLS-R and SVR calibration models for adulteration quantification demonstrates high performance capabilities for both techniques (GC-FID and FT-MIR), as indicated by high R2 correlation coefficients indicating good fit, with lower root mean square error (RMSE) values demonstrating predictive accuracy. The results suggest that FT-MIR spectroscopy is preferable to GC-FID for the quantification and discrimination of adulterated essential oils. FT-MIR spectroscopy is considered superior to GC-FID due to its non-destructiveness, speed and lack of sample preparation.

From inspection to analysis: A combined approach to identifying counterfeit whiskeys using HS-GC-FID and bottle integrity

Counterfeiting of alcoholic beverages, particularly high-value spirits such as whiskey, presents significant challenges for regulators, manufacturers, and consumers. In this study, we introduce and validate a novel application of headspace extraction (HS) followed by gas chromatography with flame ionization detection (GC-FID) for the quantitative determination of ethanol content in 42 suspected counterfeit brazilian samples of whiskeys. This method, in conjunction with visual inspection of material inconsistencies, offers a combined approach to identify potential cases of fraud. The HS-GC-FID findings revealed that only 19% of the analyzed samples had ethanol content in the limits declared on the label, emphasizing the role of ethanol content as a chemical marker for suspected beverage fraud.

Oxidative Liquefaction, an Approach for Complex Plastic Waste Stream Conversion into Valuable Oxygenated Chemicals

Various waste streams including municipal solid waste (MSW), polymer waste from personal protective equipment (PPE) used in medical fields, and composite waste from wind turbine blades (WTBs) demand modern waste management and recycling approaches. Ultimate and proximate analysis of mentioned samples revealed a higher content of carbon—28.2 ± 8.0, 80.1 ± 2.3, and 50.3 ± 2.3, respectively—exhibiting sufficient potential to be converted into secondary carbon-based compounds. For this purpose, oxidative liquefaction of selected waste materials was carried out following a detailed experimental plan, a centred composite design for WTBs, and a central composite face-centred plan for MSW and PPEs. Temperature, pressure, oxidant concentration, reaction time, and waste-to-liquid ratio were the parameters of key interest, and their values were tested at a range of 200–350 °C, 20–40 bar, 15–60%, 30–90 min, and 3–25%, respectively, depending upon the type of waste. As a result, total polymer degradation (TPD) was recorded for three types of waste and the results were satisfactory, encouraging the decomposition of primary waste in liquid oxygenated chemical compounds (OCCs). Gas Chromatography with Flame Ionisation Detection (GC-FID) helped us quantify the number of OCCs for each waste sample. Energy consumption during the process was also recorded and optimisation of the experimental plan based on maximum TPD and OCCs yields against the minimum energy consumption was performed to make the process tech-economic.

Gravimetric Preparation of Toluene CGMs in Nitrogen Gas: Verification and Stability Assessment

AbstractThis research paper presents the preparation, verification and stability evaluation of a toluene calibration gas mixtures (CGMs) in nitrogen gas via gravimetric method. These toluene gas mixtures are prepared gravimetrically i. e., by wt. mixing of high‐purity gases according to the International Organization for Standardization, ISO 6142, and are validated as per ISO 6143. Toluene gas mixtures within the range of 5 to 20 μmol/mol are prepared and traceability with SI, ‘International system of units’, amount of substance, the ′mole′, through mass‐based measurements is achieved. The verification of prepared CGMs was carried out using a GC‐FID (gas chromatography with flame ionization detector) technique, and the outcomes demonstrated a consistent linear correlation between instrumental response and gravimetric amount fraction for all gas mixtures, which confirmed the accuracy and reliability of CGMs. The gravimetric uncertainty of the prepared gas mixtures, as projected in terms of amount fractions, is below 1 % relative, while the analytical uncertainty is in the range of 2–3 % relative at a confidence level of k=1. The stability study investigation over a period of one year demonstrated that the mole fraction of toluene remained consistent throughout the entire duration, which indicated the long‐term stability of the CGMs.

Synthesis of Bio-based Polyol Via Epoxidation and Hydroxylation of Shea Butter Fats

Polyols are mostly made from petroleum and other non-biodegradable fossil fuels, and as such, they are not environmentally benign. This study presents the process of making bio-based polyols from shea butter fats (SBF) by epoxidation and hydroxylation. Wet analysis, gas chromatography with flame-ionization detection (GC-FID), and Fourier transform infrared spectroscopy (FTIR) were all used to characterize the bio-based polyols. The acid number (13.92 mg KOH/g), iodine value (19.54 mg I2/100 g), saponification value (218.03 mg KOH/g), and viscosity (107.98 poise) suggest a good quality of synthesized SBF-polyol. The FTIR analysis of SBF-polyol indicates the existence of specific vibrational frequencies: 3473 cm-1 for hydroxyl (OH) groups, 2921–2854 cm-1, and 2929–2858 cm-1 for carbon-hydrogen (C-H) and methylene (CH2) groups, respectively, and 1748 cm-1 for carbonyl (-C=O) groups. The major unsaturated fatty acids detected in SBF were oleic acid, with an estimation of 10.41%; linoleic acid and linolenic acid were reported at 0.34% and 1.67%, respectively; however, they were absent in SBF-polyol. According to this data, bio-based polyols can be synthesized using SBF and are suggested for the production of top-notch polyols.

ВЕТЕРИНАРНО-САНИТАРНАЯ ОЦЕНКА КАЧЕСТВА СЫРОГО МОЛОКА ПО ЖИРНОКИСЛОТНОМУ СОСТАВУ И СОМО

The results of a veterinary and sanitary assessment of raw milk are presented in terms of dry skimmed milk residue (SMR) and fatty acid composition (FAC). To determine the fatty acid composition, the method of gas chromatography with flame ionization detection (GC-FID) was used; SOMO was determined by calculation, with a preliminary determination of the mass fraction of dry matter and the mass fraction of fat. A total of 30 samples of raw cow's milk from private farms in the Republic of Tatarstan were examined. It was found that in the case of 56,6% of samples, the SOMO indicator did not meet the requirements of regulatory documentation (it was lower than the standardized value by 2,4 - 45,1%). In terms of FAC deviations from the established requirements were detected in four samples. At the same time, the strongest discrepancies from the established range were noted for butyric, myristic, palmitic, stearic, oleic and linoleic acids.

OPTIMIZATION AND VALIDATION OF LIQUID-LIQUID EXTRACTION (LLE) METHOD AND THE APPLICATION OF GAS CHROMATOGRAPHY WITH FID DETECTOR FOR THE DETERMINATION AND QUANTIFICATION OF VOLATILE FATTY ACIDS IN EFFLUENTS FROM ANAEROBIC REACTORS

Controlling the chemical parameters of the anaerobic digestion (AD) process is essential for the bioconversion of organic matter to methane; among these parameters include the presence and concentration of volatile fatty acids (VFAs). It is thus necessary to use efficient analytical methods that are capable of identifying and quantifying VFAs in reactor effluents in order to obtain an immediate response to their conditions. In this study, the liquid-liquid extraction (LLE) method was optimized and validated − through an adaptation of the official method, using acetone and KHSO4, and gas chromatography with flame ionization detector (GC-FID) was used for the determination of acetic, propionic, isobutyric, butyric, isovaleric and valeric acids present in the effluents. The limit of detection (LOD) and limit of quantification (LOQ) obtained were 1.2-2.5 mg L-1 and 1.9-3.7 mg L-1, respectively, for all analytes. These low LODs and LOQs are essentially important because the presence of isobutyric and isovaleric acids above 5.0 mg can be considered indicative of imbalances in AD. The proposed method, which presented satisfactory results with good repeatability (4.2-20.7%) and recovery (90.9-104.0%) rates, was applied for the analysis of effluent samples from three continuous stirred-tank reactors (CSTR).

Converting neem seed-derived oil into biodiesel using zeolite ZSM-5 as an efficient catalyst via electrosynthesis procedure: Optimization of operating variables using response surface methodology (RSM)

Biodiesel has been contemplated as the best alternative to diesel fuel, owing to its distinctive qualities which cause environmental preservation. The purpose of this research is to convert Neem Seed-Derived Oil (NSDO) into biodiesel through zeolite ZSM-5 as a heterogeneous acid catalyst, by applying an electrosynthesis technique. The response surface methodology according to central composite design (RSM-CCD) was exerted to optimize the process conditions and obtain a reliable model. Based on the RSM-CCD technique, the parametric range for optimization study was as follows: voltage of 10–40 V, time of 0.5–1.5 h, Me/NSDO of 10–30 molar ratio, and catalyst amount of 2–6 wt%. The best yield of produced biodiesel, based on the design of the experiment's model predictions, was 85.96%, and based on the experimental observations, was obtained at 86.03%, which indicates a very high adaptation of experimental design with experimental data. The optimal operating conditions, to get the best process efficiency, were as follows: voltage of 25 V, time of 1 h, Me/NSDO (Methanol to Neem Seed Derived Oil) molar ratio of 20:1, and catalyst amount of 6 wt%. The reaction yielded satisfactory results due to the catalyst's exceptional efficiency, which also demonstrated impressive performance and reusability, exhibiting only a 14% reduction in yield after five successive cycles. The catalyst was characterized by analyses, and moreover the produced biodiesel was analyzed by qualitative and quantitative analyses of FT-IR (Fourier Transform Infrared Spectroscopy) and GC-FID (Gas Chromatography with Flame Ionization Detector). As well as, to investigate the produced biodiesel quality, physicochemical analyzes were used, according to ASTM (American Society for Testing and Materials) standards, and the measured results were completely consistent with the quality characteristics of diesel fuel.

Pilot Study of 3D Spatial Distribution of α-Pinene Emitted by Norway Spruce (L.) Karst Recently Infested by Ips typographus (L. 1758) (Coleoptera: Scolytinae)

The Eurasian Spruce Bark Beetle (Ips typographus) (L. 1758) (Coleoptera: Scolytinae) poses a significant threat to Eurasia’s Norway spruce (Picea abies) (L.) Karst, forests. Early detection of infested trees is crucial to control beetle outbreaks and allow salvage logging before the next generation emerges. Besides traditional methods, new approaches focus on monitoring volatile organic compounds, mainly monoterpenes, emitted by infested trees. Using analytical chemistry, we studied the distribution of these compounds, particularly α-pinene, around infested trees. In lab trials, we optimized α-pinene detection using dynamic absorption and solid-phase microextraction (SPME), analyzed by gas chromatography with flame ionization detection (GC-FID). We conducted forest trials, revealing varying α-pinene abundance due to changing conditions. However, consistent trends emerged: levels were highest near the infested tree stem and 1.3 m above ground in the first trial and at a 1 m distance from the infested stem in the second. We generated a three-dimensional cloud depicting the distribution of α-pinene around infested trees in their natural habitat. These findings open avenues for detecting bark beetles on a large scale by mapping elevated concentrations of volatile organic compounds emitted by infested trees, potentially leading to alternative pest management methods. Scanning methods, such as electronic sensors combined with remote sensing, hold promise for this application.

A simple laboratory method for the generation of mixed brominated-chlorinated paraffin single chain mixtures

Brominated-chlorinated paraffins (Br-CPs) are a comparably new compound class that features both Cl and Br atoms on one or several alkane backbones. Due to legal restrictions in the use of conventional chlorinated paraffins (CPs), Br-CPs have the potential to become emerging contaminants. Currently, their determination is hampered by the lack of suitable reference standards. Here, we present a simple synthesis procedure with single chain alkanes that leads to Br-CPs with ∼4–8 chlorine and 1 to 4 bromine substituents according to gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS). The single-chain Br-CP mixtures were obtained by the shared chlorination and bromination of eight single-chain alkanes (C10 to C17) at two reaction times, respectively. The carbon content of the 16 single-chain Br-CP products, determined by elemental analysis (EA), ranged from 30.8 to 43.8 %. The typical hump peak known from CPs was detected with GC with flame ionization detection (GC/FID), electron capture detection (GC/ECD) and GC/ECNI-MS. The complexity indicated that low-resolution mass spectrometry is not sufficient for an adequate analysis of Br-CPs. A mathematical formula was developed which allows to calculate all possible combinations of Br and Cl that are in line with the carbon content. The proton magnetic resonance spectroscopy (1H NMR) spectra showed similarities to the ones of CPs with one chemical shift range for protons on nonhalogenated carbons and one for protons with one halogen on the same carbon.

Multi-block analysis of the oxidative stability of the palm olein and hydrogenated soybean oil during the industrial deep-frying process

The partially hydrogenated soybean oil and palm olein used in the industrial frying process were analyzed through physicochemical parameters, mid-infrared spectroscopic with attenuated reflectance (FTIR-ATR), fatty acid profile (FAP) and iodine value by gas chromatography with flame ionization detector (GC-FID), and volatile organic compounds (VOC) formation by solid-phase microextraction (SPME) in static headspace and GC-FID. The common dimension analysis (ComDim), a mid-level data fusion approach, was used to allow the multi-block exploratory data analysis of the fats. There were significant differences (p > 0.05) in acid value, peroxide value, p-anisidine value, total oxidation (Totox), and extinction coefficient at 232 nm and 270 nm between the fats before frying (T1) and after frying cycles. The percentage of (2E,4E)-Deca-2,4-dienal for organic volatile compounds was reduced, while acrolein increased. Oleic acid was predominant in both fat samples. Differences in absorption bands in the FTIR-ATR spectra enabled the distinction between partially hydrogenated soybean oil and palm olein.