Gas Chromatography Research Articles

Increased Informativeness of the Input Signal in Gas Chromatography when Using a Syringe to Introduce the Adsorbed Substance into a Column with No Adsorbent

Increased Informativeness of the Input Signal in Gas Chromatography when Using a Syringe to Introduce the Adsorbed Substance into a Column with No Adsorbent

New eco-friendly succinimide linseed oil resin: synthesis, characterization, DFT and docking studies for surface coating

Purpose The purpose of this study is to develop a new protective coating formulation for industrial use, using new eco-friendly succinimide linseed oil resin. Design/methodology/approach Epoxidized linseed oil and N-(4-hydroxy phenyl) succinimide are reacted to create succinimide-modified epoxy (SIE) compounds. The synthesized compound was confirmed by different analyses, gas chromatography, Fourier transform infrared, proton nuclear magnetic resonance and scanning electron microscopy. The prepared compound has been blended with a primer paint formulation, then their physical and mechanical properties have been studied. Density function theory is used to calculate Frontier molecular orbital including highest occupied molecular orbital and least unoccupied molecular orbital to indicate the charge transfer from molecule to biological media and molecular electrostatic potential map was used to indicate the chemically reactive zone suitable for drug action. Findings The results of the paint formulation confirmed their best performance and provided good mechanical properties and high chemical and corrosion resistance. Research limitations/implications Resin compounds are the most used antimicrobial additives. Other functionalities of these compounds, such as corrosion inhibitors, might be studied to see if they are suited for these applications. Practical implications Because of the efficiency of the SIE when incorporated with primer, paint against microbial has also been examined in silico using the docking study which contributed to the analysis of their protein binding. This type of epoxy compound is environmentally friendly and can be used as a biocide with different paint formulations. As a result, paint compositions including this compound as additives can be used as dual-purpose paint and for a variety of industrial applications. Originality/value This research demonstrates how a low-cost paint composition based on synthesized SIE compounds may be used as a dual-function paint for industrial use.

In Situ Synthesis of Hypercrosslinked Polymer as Stationary Phase for Capillary Gas Chromatography

Hypercrosslinked polymers (HCPs) constructed by the Friedel–Crafts alkylation reaction of aromatic compounds have emerged as a new class of porous materials with unique merit. Herein, a HCP named HCP-TPB was coated onto a capillary column through in situ synthesis. The prepared column exhibited a nonpolar nature, and the column efficiency for n-dodecane was 3003 plates m−1. Moreover, the relative standard deviations of retention time and peak area for six replicate injections of the C3–C6 were lower than 0.1% and 1.5%, respectively. The results of this study showed that it is very promising to utilize HCPs as stationary phases for the separation of C3–C6.

Preliminary phase results of GC-MS analysis and cytotoxic activity of Argemone mexicana leaves methanol extract against MCF-7 cell lines

Argemone mexicana leaves (AML) contain a variety of bioactive components such as fatty acids, amino acids, phenolics and alkaloids, including Berberine, Isoquinoline, Scoulerine, Stylopine, Thalifone, Benzylisoquinolines, Protopine, and Tetrahydroberberine. This study aimed to examine the gas chromatography and mass spectrometry (GC-MS) analysis of AML extract and its cytotoxic activity on MCF-7 cell lines to identify an alternative source for anticancer treatment. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was utilized to assess the viability of AML extract-treated cells, while the apoptotic assay involved Acridine orange staining to determine the mode of cell death based on morphological and nuclear fragmentation. The GC-MS analysis was used to identify the biologically active compounds. The results showed that the percentage of cell viability after AML extract treatment ranged from 28.50% to 64.28% for concentrations of 1000 to 125 μg/ml (IC50 = 258.87 μg/ml). Statistical analysis revealed a significant difference in cell viability (p < 0.05). Exposure of cells to AML extract stimulated apoptosis through membrane blebbing, cell shrinkage, cytoplasm condensation, and nuclear fragmentation. Forty-one compounds were identified by GC-MS in the AML extract. Based on the peak area, some major compounds included n-Hexadecanoic acid (palmitic acid), 9,12-Octadecadienoic acid (Z, Z)-, Phytol, 9,12,15-Octadecatrienoic acid (Z, Z, Z)-, and 1-methyl piperidine. In conclusion, the bioactive compounds are apparently responsible for the cytotoxic effects of the AML extract, and the in-vitro results highlight the extract’s potential as a source of natural anticancer drugs. However, further investigation is necessary to confirm this.

Immunization of male BALB/c and C57BL/6 mice similar modulates chemical signals detected in both chromatographic and behavioral tests

The odor plays a key role in communication between animals and the choice of a mate. The odor of urine of males becomes less attractive to mature females after infection or activation of the immune system. The development of the immune response in the early stages is related with the production of both pro-inflammatory and anti-inflammatory cytokines. To investigate the chemical basis of the observed differences and examine the influence of female interactions with the odor of antigen-treated males, we immunized males of inbred BALB/c (Th1) and C57BL/6 (Th2) mice with hemocyanin (KLH). For females of both tested strains, the attraction of the odor of male urine collected 3 days after immunization was lower compared with the odor of control males. Herewith, BALB/c females sniffed the urine of immunized males less frequently, and C57BL/6 females demonstrated a shorter duration of grooming in olfactory tests with urine of immunized males. The altered response of females to the odor of male urine collected on day 3 after KLH injection matched with antigen-induced modulation of relative levels of volatile organic compounds (VOCs) detected in urine samples by gas chromatography and mass spectroscopy (GC-MS). In males of both strains, after KLH injection, an increase in the content of nonanal, benzothiazole, as well as 2-sec-butyl-4,5-dihydrothiazole, and [1,4,5]-oxadithiepane was shown. At the same time, no compounds were found, the content of which changes in different directions in the urine of males after immunization, depending on the strain of the animal.

Impact of Nano-Pomegranate Seed Oil on the Expression of TLR2 and TLR4 Genes in A549 Cells Sensitized with Alternaria alternata Cellular Extract

Background: Allergies impact nearly 30% of the world's population, with fungi being remarkable contributors to allergic sensitivity. Exposure to fungi allergens can trigger allergic reactions and severe asthma has been linked to hypersensitivity to fungi such as Aspergillus and Alternaria spp. Alternaria alternata, a common allergen in respiratory allergic diseases, releases proteases that initiate Th2 responses, causing inflammatory cytokine production. Given the anti-inflammatory properties of Pomegranate Seed Oil (PSO) and the potential of Nano-emulsions (NEs) to enhance drug delivery, this study investigates the impact of PSO-loaded NEs on TLR2 and TLR4 gene expression in A549 cells sensitized with A. alternata extract (ALT). Methods: A. alternata (ATCC 6663) was cultured and processed to obtain a cytosolic extract, with protein content measured using the Bradford method. Using a Soxhlet apparatus, PSO was extracted from cleaned, dried seeds and analyzed by gas chromatography. Alginate nanospheres containing PSO were prepared through a modified water-in-oil emulsification method and characterized for particle size, polydispersity index, and zeta potential. A549 cells were cultured and treated with various ALT, PSO, and PSO-loaded NEs combinations. Following treatment, RNA was extracted, and real-time RT- PCR was conducted to analyze TLR2 and TLR4 gene expression. Results: All treatment groups showed an increase in TLR2 gene expression compared to the control, with the ALT combined with PSO (P+ALT) causing the highest increase at 4.82-fold. Free PSO (P) and free NEs (NP) resulted in 3.92-fold and 2.93-fold increases, respectively, while the ALT and PSO- loaded NEs (NP+ALT) led to 2.26-fold and 2.50-fold increases. For TLR4 gene expression, the ALT treatment increased expression by 2.29-fold, but treatments containing PSO (P, P+ALT, NP+ALT) reduced TLR4 expression, with P+ALT and NP+ALT causing 0.45-fold and 0.61-fold decreases. Conclusion: The study confirms that herbal extracts like PSO selectively upregulate TLR2 and downregulate TLR4, suggesting targeted therapeutic potential in inflammation and immune modulation. PSO-loaded NEs demonstrated superior anti-inflammatory effects, supporting their development for treating inflammatory diseases and warranting further research into their molecular mechanisms and therapeutic applications.

Cover Image

The cover image is based on the article Identification of volatile differential markers in strong‐aroma Baijiu based on gas chromatography–electronic nose combined with gas chromatography–time‐of‐flight mass spectrometry by Aliya, Yufa Cao et al., https://doi.org/10.1002/jsfa.13855. image

Lipophilic index of serum phospholipids in patients with type 2 diabetes and atherosclerotic cardiovascular disease: links with metabolic control, vascular inflammation and platelet activation.

Little is known about the mechanisms underlying the association of the serum phospholipid lipophilic index (LI) with atherosclerotic cardiovascular disease (ASCVD) in patients with type 2 diabetes (T2D). Therefore, we investigated whether the LI is associated with glucometabolic control, meta-inflammation, thrombin generation, fibrin clot properties, endothelial function and platelet activation in T2D patients with angiographically documented ASCVD. We studied 74 T2D patients with ASCVD, aged 65.6 ± 6.8 years, with a median diabetes duration of 10 years and median HbA1c of 7.0%. Serum phospholipid fatty acids (FAs) were measured by gas chromatography. The serum phospholipid LI was calculated as the sum of the products of the proportion (% of total FAs) with the melting points (°C) of each individual FA, divided by the sum of the proportions of all FAs. Levels of HbA1c, insulin, leptin, adiponectin, lipid profiles, inflammatory markers (hsCRP, interleukin-6, TNF-α), Lp-PLA2 (a biomarker of vascular inflammation), endothelial function (sICAM-1, sVCAM-1, FMD, NMD), thrombin generation, fibrin clot properties and platelet activation, measured by light transmission aggregometry with arachidonic acid [AA] and adenosine diphosphate [ADP], were assessed. Patients with LI > 16.9°C (median) had higher HbA1c concentrations by 5.9% compared to the remaining subjects (p = 0.035). In this group, HbA1c levels ≥ 7.0% were found more often than in individuals with LI ≤ 16.9°C (62.2 vs. 35.1%; p = 0.020). Subjects with LI > 16.9°C had higher levels of TCh by 17.1% (p = 0.012), LDL-Ch by 29.4% (p = 0.003), interleukin-6 by 22.2% (p = 0.031) and Lp-PLA2 by 32.4% (p = 0.040), compared to the remaining patients. Moreover, they had increased maximal platelet aggregation induced by AA (p = 0.045), but not by ADP. Serum phospholipid LI correlated with HbA1c (r = 0.24; p = 0.037), TCh (r = 0.36; p = 0.002), LDL-Ch (r = 0.38; p < 0.001), interleukin-6 (r = 0.27; p = 0.020) and Lp-PLA2 (r = 0.26; p = 0.026). There were no intergroup differences in endothelial function, thrombin generation and fibrin clot properties. Regression analysis showed that HbA1c ≥ 7.0% and serum levels of LDL-Ch, interleukin-6 and Lp-PLA2 were predictors of LI > 16.9°C in adjusted models. In well-controlled T2D patients with ASCVD, the higher serum phospholipid LI is associated with worse glucometabolic control, enhanced vascular inflammation and higher platelet reactivity during aspirin treatment at cyclooxygenase-1-selective doses.

Aroma Identification and Traceability of the Core Sub-Producing Area in the Helan Mountain Eastern Foothills Using Two-Dimensional Gas Chromatography and Time-of-Flight Mass Spectrometry and Chemometrics

The combination of volatile compounds endows wines with unique aromatic characteristics and is closely related to their geographical origins. In the pursuit of origin identification and the subdivision of homogeneous production areas, clarifying the characteristics of production areas is of great significance for improving wine quality and commercial value. In this study, GC×GC-TOFMS technology was used to analyze the aroma characteristics of “Cabernet Sauvignon” wines from 26 wineries in the Helan (HL), Yinchuan (YC), Yongning (YN), Qingtongxia (QTX), and Hongsibu (HSP) sub-producing areas in the eastern foothills of Helan Mountain in Ningxia, China. The results indicate a gradual increase in relative humidity from the southern part of Ningxia, with the YN sub-region showing optimal fruit development and the QTX region having the highest maturity. A total of 184 volatile compounds were identified, with 36 compounds with an OAV &gt; 1, crucial for the aroma profiles of primarily fermentation-derived alcohols and esters. An aromatic vector analysis revealed that “floral” and “fruity” notes are the primary characteristics of Cabernet Sauvignon wines from the Helan Mountain East region, with lower maturity aiding in the retention of these aromas. By constructing a reliable OPLS-DA model, it was determined that 15 substances (VIP &gt; 1) played a crucial role in identifying production areas, among which phenylethyl alcohol and isoamyl alcohol were the main contributors. In addition, a Pearson correlation analysis showed a negative correlation between sunlight duration during the growing season and benzyl alcohol accumulation, while a significant positive correlation was observed during the ripening period. Due to the critical role of phenyl ethanol in identifying producing areas, this further demonstrates that sunshine conditions may be a key factor contributing to the differences in wine flavor across regions. This study offers a theoretical foundation for understanding the relationship between climatic factors and flavor characteristics, addressing the issue of wine homogenization in small production areas, clarifying typical style characteristics, and establishing a traceability technology system based on characteristic aroma.

Evaluation of flavor characteristics in Chinese wheat flour paste using electronic-nose, electronic-tongue, and headspace-gas chromatography-ion mobility spectrometry at different fermentation stages.

Wheat flour paste is a typical Chinese fermented food, valued for its distinct flavors and health benefits. However, evidence regarding volatile organic compounds (VOCs) in Chinese wheat flour paste is limited. This study aims to examine the effect of fermentation on the VOCs and their physicochemical properties. Chinese wheat flour paste fermented at different stages was characterized using headspace gas chromatography ion-mobility spectrometry (HS-GC-IMS) with an electronic nose (E-nose) and an electronic tongue (E-tongue). The results revealed that around 76 VOCs were found in Chinese wheat flour paste from all stages of fermentation. These included esters, alcohols, aldehydes, ketones, acids, furans, and pyrazines. The E-tongue and E-nose analyses also showed high responses for saltiness, umami, WIW, and W5S. The fermentation process changed the color of the wheat flour paste, and the taste, and smell parameters. Principal component analysis (PCA) showed that taste parameters were positively associated with the volatile flavor profile detected in wheat flour paste. Partial least squares discriminant analysis also identified 28 VOCs as distinct flavor metabolites across fermentation stages. At the 'after ripening' (AR) and 'sterilization' (S) stages of wheat flour paste fermentation there were strong umami and salty flavors, with minimal sour and sweet notes in comparison with the other stages. These stages were characterized by elevated terpene concentrations, inorganic sulfides, and key flavor enhancers such as 2-hexanol and propyl sulfide. Headspace gas chromatography ion-mobility spectrometry and E-nose technologies are recommended for a more precise assessment of volatile changes during fermentation. The findings indicate that the 'sterilization' stage of wheat flour paste fermentation is optimal for achieving the required flavor profile. © 2024 Society of Chemical Industry.

Mycosynthesis of silver nanoparticles from endophytic Aspergillus parasiticus and their antibacterial activity against methicillin-resistant Staphylococcus aureus in vitro and in vivo

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a drug-resistant and biofilm-forming pathogenic bacteria with severe morbidity and mortality. MRSA showed resistance against currently available antibiotics. Thus, there is an urgent need to develop novel effective treatments with minimal side effects to eliminate MRSA.AimIn this study, we aimed to mycosynthesize silver nanoparticles (AgNPs) using the endophytic fungus Aspergillus parasiticus isolated from leaves of Reseda Arabica and to examine their antibacterial activity against MRSA.ResultsScreening of fungal secondary metabolites using gas chromatography–mass spectroscopy (GC–MS) analysis revealed the presence of high content of bioactive compounds with antibacterial activities. AP-AgNPs were mycosynthesized for the first time using ethyl acetate extract of A. parasiticus and characterized by imaging (transmission electron microscopy (TEM), UV–Vis spectroscopy, zeta potential, X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and Fourier transform infrared spectroscopy (FTIR)). The agar well diffusion method revealed the antibacterial activity of AP-AgNPs against MRSA with 25 μg/mL of minimum inhibitory concentration (MIC). AP-AgNPs were shown to exert antibacterial action via a bactericidal mechanism based on flow cytometry, scanning electron microscopy, and transmission electron microscopy assessment. Our data demonstrated the effective interaction of AP-AgNPs with the bacterial cell membrane, which resulted in cell membrane damage and disruption of cell surface structure. Furthermore, AP-AgNPs successfully prevented the development of MRSA biofilms by disturbing cell adhesion and destructing mature biofilm reaching over 80% clearance rate. Interestingly, topical application of AP-AgNPs to superficial skin infection induced by MRSA in mice effectively promoted wound healing and suppressed bacterial burden.ConclusionOur results provide a novel green nanoparticle drug design with effective therapeutic potential against MRSA-induced skin infection.

Anticancer and antiproliferative activities of Algerian Origanum majorana L.’s essential oil on PC-3 and SKBR3 cells

Cancer is a prominent cause of death globally, with breast cancer and prostate cancer being among the most devastating types. Therefore, the available anticancer treatments have some drawbacks, like higher toxicity and limited bioavailability. Thus, this study aimed to investigate for the first time the anticancer activity of Algerian Origanum majorana L.’s essential oil (OMEO). This research assessed the chemical profile of Algerian OMEO by gas chromatography coupled with mass spectrometry (GC-MS). The analysis revealed 29 compounds, which represent 98.08% of total volatile oil. The major compounds identified in OMEO were terpinen-4-ol (21.37%), γ-terpinene (15.78%), α-terpinene (10.43%), and trans-sabinene hydrate (9.27%). Additionally, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) was also used to test the cytotoxicity on prostate cancer (PC-3), breast cancer (SKBR3), and normal retinal pigment epithelium (ARPE-19) cell lines. The results showed a selective cytotoxicity effect by decreasing cell viability of PC-3 cancer cells with half inhibitory concentration (IC50) of 608.57 μg/mL and 672.5 μg/mL after 48h and 72h, respectively. Regarding SKBR3 cancer cells, the IC50 was 991.5 μg/mL. OMEO exhibited no significant cytotoxicity against normal (ARPE-19) cells. Furthermore, we conducted a cell apoptosis assay using Hochest 33342 dye to explore the potential mechanism pathway of OMEO. The findings verified that OMEO could trigger apoptosis in PC-3 and SBKR3 cancer cells. The ability of OMEO to inhibit cell migration assessed via wound healing assay revealed a significant decrease in cell migration. Our results imply that OMEO decreases cell viability by inducing cell apoptosis. Moreover, the oil suppresses cell migration in prostate cancer and breast cancer cells.

GC-MS/HPLC Profiling and Sono-Maceration Mediated Extraction of Osbeckia Parvifolia Polyphenols: In Silico and In Vitro Analysis on Anti-Proliferative Activity in Ovarian Cancer Cell Lines.

Osbeckia parvifolia, an endemic edible plant of Western Ghats, was investigated in the present study for its polyphenolic compounds, including content, constituents, extraction through an ultrasonic-assisted maceration technique and therapeutic potential in biomedical applications. The methanolic extract (OPM) exhibited an IC50 value of 1.25 μg/mL against 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radicals. Furthermore, the ethyl acetate and methanolic extracts also strongly inhibited 5-lipoxygenase, especially OPM (84.93 %), which was comparable to standard curcumin. OPM also elicited cytotoxicity in SKOV3 ovarian cancer cells (93.80 %), surpassing paclitaxel. Bio-accessibility analysis demonstrated that the release of phenolic compounds and antioxidant potential were very high (above 100 %), revealing the possibility of synergistic efficacy of polyphenolic complexes in drug development. Gas Chromatography -Mass Spectrometry (GC-MS) analysis revealed 22 bioactive polyphenolic compounds in OPM, such as epicatechin, quercetin, and psoralidin. This was confirmed by High Performance Liquid Chromatography (HPLC) and High-Pressure Thin Layer Chromatography (HPTLC) analyses, which revealed a high quantity of catechin (37.45 mg/g). Molecular docking revealed the significant binding affinity of these proteins for the ovarian oncoproteins PI3K (-8.52 kcal/mol) and Casp-8 (-8.41 kcal/mol). Adsorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) profiling indicated the favorable pharmacokinetic properties of these compounds, supporting their candidacy in drug formulations against ovarian cancer.

Biomarkers improving genetic and metastatic disease prediction in paraganglioma: insights from a prospective study.

Identifying the risk of malignancy and genetic status in primary paraganglioma or pheochromocytoma (PPGL) is a key challenge. The aim was to assess the diagnostic accuracy of genomic, metabolomic and histopathological biomarkers for predicting metastatic and genetic status. COMETE-TACTIC is a prospective study (NCT02672020) conducted from November 2015 to March 2019 across 16 referral centers. Tumor samples and liquid biopsies from 231 consecutive patients with PPGL were collected. Germline and somatic genetic status were determined by NGS. SDHB, SDHA and CA9 immunohistochemistries were performed on tumor tissues. TERT promoter methylation was assessed by pyrosequencing. Metabolomic profile and circulating miRNAs were measured in liquid biopsies by gas chromatography MS/MS and TaqMan assay quantified by droplet digital PCR, respectively. Tumor analysis outperformed germline analysis for determining genetic status. Positive SDHA and SDHB staining combined with negative CA9 labeling indicated the absence of SDHx and VHL variants. Plasma succinate levels above 4.94µM identified SDHx mutation carriers with 65% sensitivity and 92% specificity (AUC-ROC 0.82, 95%CI 0.70-0.93). Among circulating miRNAs, miR-483-5p was the best classifier of metastatic status (AUC-ROC 0.64, 95%CI 0.52-0.77). A sum of dinucleotide methylation rate of TERT promoter CpGs above 42% predicted metastatic status (AUC-ROC 0.75, 95%CI 0.65-0.85). Multivariate analyses showed that biomarker combinations significantly predicted SDHx status (AUC-ROC 0.99, 95%CI 0.98-1.00) and metastatic potential (AUC-ROC 0.93, 95%CI 0.84-1). Circulating miR-483-5p, plasma succinate, TERT promoter methylation, and SDHB immunostaining are valuable for PPGL risk stratification. Combining biomarkers with clinical data provides excellent diagnostic accuracy for metastatic patients (AUC-ROC 0.97, 95%CI 0.93-1).

A Noncovalent π‐Stacked Dual‐Pore Molecular Crystal for Ethanol/Water and Benzene/Methanol Azeotrope Separation

Separation of ethanol/water or benzene/methanol azeotrope mixtures presents significant challenges, not only due to the limitations of conventional distillation techniques but also because of the constraints in developing and utilizing of new generation adsorbents. Porous organic molecular frameworks constructed via noncovalent π‐interactions are emerging as novel adsorbents with vast potential in gas adsorption and molecular separation. Herein, we report a permanent two‐dimensional porous structure, namely TDTBA‐1, which consists of two different kinds of pores through π‐stacking of a single organic molecule with highly Td symmetry. Activated TDTBA‐1 exhibits excellent hydrophobicity, thermal stability, recoverability and high selectivity for ethanol over water, and benzene over methanol. Therefore, activated TDTBA‐1 can be used as an efficient stationary phase for the separation of ethanol/water and benzene/methanol azeotropes by high‐resolution gas chromatography.

A Noncovalent π-Stacked Dual-Pore Molecular Crystal for Ethanol/Water and Benzene/Methanol Azeotrope Separation.

Separation of ethanol/water or benzene/methanol azeotrope mixtures presents significant challenges, not only due to the limitations of conventional distillation techniques but also because of the constraints in developing and utilizing of new generation adsorbents. Porous organic molecular frameworks constructed via noncovalent π-interactions are emerging as novel adsorbents with vast potential in gas adsorption and molecular separation. Herein, we report a permanent two-dimensional porous structure, namely TDTBA-1, which consists of two different kinds of pores through π-stacking of a single organic molecule with highlyTdsymmetry. Activated TDTBA-1 exhibits excellent hydrophobicity, thermal stability, recoverability and high selectivity for ethanol over water, and benzene over methanol. Therefore, activated TDTBA-1 can be used as an efficient stationary phase for the separation of ethanol/water and benzene/methanol azeotropes by high-resolution gas chromatography.

Residue analysis of premix formulation of fipronil and imidacloprid and its metabolites in hot pepper (Capsicum annum)

A field experiment was conducted during 2018–19 and 2019–20 at Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana to assess the dissipation pattern of a ready mix formulation i.e. fipronil and imidacloprid along with their metabolites in fruits of hot pepper (Capsicum annum L.). The Hot pepper variety Kranti was used for the study. Quantitative analysis was done on gas liquid chromatography (GLC) and high pressure liquid chromatography (HPLC) for fipronil and imidacloprid with their metabolites, respectively. At the suggested dose, fipronil residues were lower than 0.01 mg/kg in the studied years. However, in double doses, the total residues of fipronil were detected on the 5th (0.071 mg/kg) and 3rd (0.043 mg/kg) day for the 1st and 2nd year following drench application. Imidacloprid was detected only in the subsequent year’s trial in double doses. Residual leftovers of imidacloprid metabolite (6- CNA) were lower than 0.01 mg/kg (LOQ). No residual leftovers were present in fully ripened red chilli and harvest time samples of soil.

Investigating the Reduction of Fluoroethylene Carbonate and Vinylene Carbonate in Lithium‐Ion Cells with Silicon‐Graphite Anodes

AbstractThe electrolyte additives fluoroethylene carbonate (FEC) and vinylene carbonate (VC) improve the lifetime of lithium‐ion batteries with silicon‐containing anodes by their reduction yielding a more stable solid electrolyte interphase (SEI). However, the reductive decomposition mechanism of FEC and VC has not yet been fully clarified. For this purpose, we investigate the electrolyte decomposition in LiNi0.6Co0.2Mn0.2O2 (NCM622)/silicon‐graphite pouch cells containing either 1 M LiPF6 in FEC:dimethyl carbonate (DMC) or 1 M LiPF6 in VC:DMC using high‐performance liquid chromatography, gas chromatography, X‐ray photoelectron spectroscopy, and inductively coupled plasma optical emission spectrometry. Based on the molar consumptions of FEC and VC, and the cumulative irreversible capacities, we show that three electrons are consumed for every reduced FEC molecule, and that one electron is consumed for every reduced VC molecule. Based on the results, reactions of the FEC reduction are proposed yielding LiF, Li2CO3, Li2C2O4, HCO2Li, and a PEO‐type polymer. Furthermore, the reaction of the VC reduction is proposed yielding lithium‐containing, polymerized VC. During formation, the capacity loss of the cells is induced by lithium trapping in LixSiy/LixSiOy under the SEI and by lithium trapping in the SEI. During subsequent cycling, only lithium trapping in the SEI triggers the capacity loss.

Measurements of hydrogen deposition velocities by farmland soil using D2 gas.

Using D2 gas as a substrate, this study investigated the hydrogen deposition velocities of farmland soils around a reprocessing plant located in Rokkasho Village, Aomori, Japan. To determine the hydrogen deposition velocities, closed chambers with fans were set on the soils of farmlands that grow Japanese radishes, and changes in D2 concentration in the chambers were measured by gas chromatography. Results showed hydrogen deposition velocities of six soils were within the range of 1.0×10-4~2.0×10-4ms-1. The heavy water (HDO) formations were detected in the soil after the experiment, showing the oxidation of D2 and conversion to water. Relationships between the obtained hydrogen deposition velocities and environmental conditions such as soil temperature, moisture and porosity were examined. A correlation was found between the hydrogen deposition velocities and soil gas phase rate (r=0.98, p<0.05).

Geochemical characteristics of lacustrine source rocks and oil-source correlation of the Yanchang Formation in the Zizhou area, Ordos Basin

The Zizhou area on the northeastern margin of the Ordos Basin has achieved major breakthroughs through continuous exploration over the years, demonstrating high potential for hydrocarbon exploration. However, due to the underdevelopment of source rocks, the origin of crude oil in the Chang 6 and Chang 4 + 5 Members remains unclear, which significantly hinders further hydrocarbon exploration. In this study, we use Rock-Eval pyrolysis, kerogen maceral analysis, quantitative gas chromatography (GC) of saturated hydrocarbons, and GC-mass spectrometry of saturated and aromatic hydrocarbons to determine the geochemical characteristics of source rocks and oils from different sedimentary environments. In addition, we select effective biomarker parameters to identify the source of oil in the Chang 6 and Chang 4 + 5 Members in the Zizhou area. The results indicate that the Chang 7 Member source rocks have organic matter abundances ranging from good to excellent, with types classified as type I-II1, and are in a mature stage. Source rocks from the semideep to deep lacustrine facies exhibit a clear predominance of low-carbon number hydrocarbons, a higher proportion of short-chain n-alkanes, relatively lower C24 tetracyclic terpane/C26 tricyclic terpane (C24TeT/C26TT) and C30 hopane/C30 diahopane (C30H/C30DiaH) ratios, and similar abundances of C27 and C29 steranes. In contrast, deltaic facies source rocks, which developed in suboxic to oxic environments, display opposite characteristics. The reservoir extracts from the Zizhou area indicate a high degree of similarity to the deltaic facies source rocks. Moreover, the subtle geochemical differences between the reservoir extracts and their potential source rocks are mainly attributed to geochromatographic effect during hydrocarbon migration and differences in preservation conditions. These findings provide new insights into the dynamics of hydrocarbon migration and accumulation in the northeastern margin of the Ordos Basin and further reinforce the reliability of using biomarker techniques to determine the relationship between crude oil and its source.