Gas Chromatography-mass Spectrometry Method Research Articles

Chemical components in cultivated Cordyceps sinensis and their effects on fibrosis

ObjectiveCultivated Cordyceps sinensis powder has been used as clinical drug and healthy food to nourish the lung and kidney, which solves the problem of serious shortage of wild C. sinensis. This study aims to explore the chemical components and compared their anti-fibrotic effects in cultivated C. sinensis. MethodsNucleosides, sterols and polysaccharides were separated and purified from cultivated C. sinensis, and analyzed by high performance liquid chromatography, gas chromatography-mass spectrometry and chemical chromogenic methods, respectively. In high glucose-induced rat mesangial cell models, fibronectin and type 1 collagen were used as evaluation indicators. ResultsThere were 10 kinds of nucleosides and one sterol in cultivated C. sinensis. The contents of nucleosides, sterols and polysaccharides in the cultivated C. sinensis were close to 2%, 0.55% and 4.4%, respectively. Furthermore, nucleoside, sterol and polysaccharide components exhibited varying degrees of anti-fibrotic activity. The nucleoside components and sterol components inhibited the expression of extracellular matrix more effectively in the three main components. ConclusionCultivated C. sinensis remains the similar compounds with the wild C. sinensis, and nucleosides and sterols may be the main active substances that contribute to its anti-fibrotic effects. The project of this study may provide valuable information on further optimization of more effective remedies with few side effects based on cultivated C. sinensis.

Children victims of drug abuser parents: Hair testing as a forensic tool to assess exposure-A cohort of 37 cases from Spain.

Hair testing is a useful tool to investigate suspected pediatric exposure to drugs of abuse. Newborns and young children are at high risk of exposure to drugs of abuse from parents or caregivers who consumed these substances, a fact prosecuted by Spanish authorities as child abuse. A retrospective study based on a cohort of 37 cases classified using several parameters, which involve children under 12years old, were analyzed at the Drugs Laboratory of the National Institute of Toxicology and Forensic Sciences (Madrid, Spain) between 2009 and 2021. Hair samples were tested for the presence of opiates, cocaine, ketamine, amphetamines, methadone, and cannabis using a gas chromatography-mass spectrometry (GC-MS) method. A 59% of the studied children had ages in the range of 1-3years old, and in 81% of cases, victims required hospitalization. In 81% of cases (n = 30), hair was submitted only or in combination with other samples, and these were classified in four categories according to analyzed samples: A (only hair), B (hair and blood), C (hair and urine), and D (hair, blood, and urine). The 93.3% of these cases (n = 28) showed a positive result of cannabinoids (THC and CBN in hair and THC-COOH in urine; 71.4% n = 20), cocaine and metabolites (benzoylecgonine and cocaethylene; 46.4% n = 13), opiates (morphine and 6-acetylmorphine), and amphetamines (MDMA and MDMA; 3.10% n = 1). Hair analysis matched positive results in cases where urine screening test was carried out previously (n = 24) and in those cases where blood and/or urine were also submitted (35.6% n = 11). As a conclusion, hair analysis was confirmed as a useful tool to detect previous exposure to acute poisoning events in children.

Application of Direct Thermal Desorption-Gas Chromatography-Mass Spectrometry for Determination of Volatile and Semi-Volatile Organosulfur Compounds in Onions: A Novel Analytical Approach.

The population is now more aware of their diets due to the connection between food and general health. Onions (Allium cepa L.), common vegetables that are minimally processed and grown locally, are known for their health-promoting properties. The organosulfur compounds present in onions have powerful antioxidant properties and may decrease the likelihood of developing certain disorders. It is vital to employ an optimum approach with the best qualities for studying the target compounds to undertake a thorough analysis of these compounds. In this study, the use of a direct thermal desorption-gas chromatography-mass spectrometry method with a Box-Behnken design and multi-response optimization is proposed. Direct thermal desorption is an environmentally friendly technique that eliminates the use of solvents and requires no prior preparation of the sample. To the author's knowledge, this methodology has not been previously used to study the organosulfur compounds in onions. Likewise, the optimal conditions for pre-extraction and post-analysis of organosulfur compounds were as follows: 46 mg of onion in the tube, a desorption heat of 205 °C for 960 s, and a trap heat of 267 °C for 180 s. The repeatability and intermediate precision of the method were evaluated by conducting 27 tests over three consecutive days. The results obtained for all compounds studied revealed CV values ranging from 1.8% to 9.9%. The major compound reported in onions was 2,4-dimethyl-thiophene, representing 19.4% of the total area of sulfur compounds. The propanethial S-oxide, the principal compound responsible for the tear factor, accounted for 4.5% of the total area.

Antimicrobial activity and constituents of the leaf essential oil of Syzygium petelotii Merr. & Perry and Syzygium syzygioides (Miq.) Merr. & Perry from Vietnam

Syzygium plants are known as sources of biologically active substances. The essential oils constituents and antimicrobial activity of Syzygium petelotii Merr. & Perry and Syzygium syzygioides (Miq.) Merr. & Perry from Vietnam are being reported. Essential oils were obtained by hydrodistillation of the leaves of S. petelotii and S. syzygioides collected from Pù Hoạt Nature Reserve, Vietnam. The constituents of the essential oils were determined by using gas chromatography (GC) and gas chromatography-mass (GC/MS) spectrometry methods. The antimicrobial activity was evaluated by microdilution broth susceptibility assay. The results indicate that γ-guaiene (24.1%), β-caryphyllene (9.3%), α-pinene (7.8%), and β-pinene (6.1%) were the major compounds of S. petelotii. The main constituents of S. syzygioides were caryophyllene oxide (14.8%), α-pinene (10.6%), β-pinene (6.6%) and spathulenol (6.4%). The essential oil of S. petelotii showed pronounced antimicrobial activity against Pseudomonas aeruginosa ATCC27853 and Enterococcus faecalis ATCC299212, with minimum inhibitory concentration (MIC) values of 16.0 μg/mL and 64.0 μg/mL, respectively. The essential oil of S. syzygioides only displayed activity towards Pseudomonas aeruginosa ATCC27853 with MIC value of 32.0 μg/mL. Both essential oils exhibited antimicrobial activity towards Bacillus cereus ATCC14579 (MIC value, 128.0 μg/mL), and anti-candidal action against Candida albicans ATCC10231 with MIC value of 64.0 μg/mL. The chemical compositions and antimicrobial activity of essential oils of S. petelotii and S. syzygioides are being reported for the first time.

Development and validation of a rapid GC–MS method for seized drug screening

Controlled substances are one of the most commonly analyzed types of evidence in forensic laboratories. Persistent, high levels of case submissions in recent years have created a need for rapid screening techniques to decrease case backlogs and expedite confirmatory analyses. The most utilized technique for the analysis of seized drugs is gas chromatography mass spectrometry (GC-MS). While this approach typically takes tens of minutes, advances in the technique have enabled approximately 1 min run times with a short column and a rapid (10’s °C/s) temperature program. These advances were used in this work to develop and validate a rapid GC-MS method for screening seized drug samples. Method validation was completed to determine retention time repeatability and reproducibility, limits of detection, identification accuracy, selectivity, and carryover. Validation results showed the utility of this method for accurate and precise qualitative analyses for the screening of seized drugs across seven different drug classes. The optimized method was then applied to 15 real and mock case samples from the Maryland State Police Forensic Sciences Division. Controlled substances, cutting agents, and other diluents were identified from these samples using acceptance criteria of retention time and mass spectral comparisons currently used in casework. Using rapid GC-MS methods in casework could enable faster and more reliable presumptive testing results for the analysis of seized drug exhibits.

CHANGE CHARACTERISTICS IN SALIVA AND FECES MICROBIOTA OF A DESMINOPATHY T341P PATIENT

Background. A rare muscular disease, desminopathy, is caused by mutations in the DES gene. At present, information about changes in the microbiota of biological media present in such patients is very scarce.
 Purpose. The aim of the study is to study changes in the saliva and feces microbiota of patients with desminopathy T341P in a heterozygous state.
 Materials and methods. The retrospective investigation comprised observation of the observation of a proband with the family form of desminopathy T341P. 56 clinically significant microorganisms were numerically analyzed immediately in the obtained biological material by gas chromatography-mass spectrometry method.
 Results. The emergence of Epstein-Barr viruses, Cytomegalovirus, Herpes spp and gram-negative rods was noted in the proband’s biological media under investigation during the desminopathy progression. Excessive bacterial growth of fecal microbiota was observed along with a decrease in saliva microorganisms. There is an excess of the norm in the total number of microorganisms and an increase in their species diversity. Propionibacterium jensenii, Eubacterium spp and Eggerthella lenta predominated in the feces and Clostridium ramosum – in the saliva. An increase in fecal microbiota transient with Peptostreptococcus anaerobius 18623 dominance was observed along with the emergence and rapid 441-time growth of potentially dangerous bacterium Clostridium difficile. The total level of endotoxin in the proband’s saliva and fecal microbiota increases to exceed the norm in 13.7 and 81.8 times, respectively. At the same time, a low level of plasmalogen was noted.
 Conclusion. The investigation results can be useful for developing complex intervention tactics.

Analysis of tetramisole metabolites- Is "Aminorex" found in Forensic Samples of Cocaine Users actually 4-Phenyl-2-imidazolidinone?

Phenyltetrahydroimidazothiazole (PTHIT, tetramisole) is a common adulterant in cocaine samples. Little is known on its human metabolism. p-hydroxy-PTHIT has long been the only proven phase-I-metabolite. Another putative metabolite is the stimulant aminorex. However, data on its analytical proof is rare and contradictory. Even less known is its constitutional isomer 4-phenyl-2-imidazolidinone which has only been proven in animal samples so far. Aim of the study was to get insight into the metabolism of PTHIT after controlled nasal uptake of PTHIT and in real forensic cocaine/benzoylecgonine-positive samples. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated for quantification of 4-phenyl-2-imidazolidinone and p-hydroxy-PTHIT (LOQ 0.05 ng/mL each). Selectivity was ensured for 4-phenyl-2-imidazolidinone and aminorex (LOD 0.05 ng/mL). After controlled nasal uptake of tetramisole (10 mg, n=3) a shorter half-life for p-hydroxy-PTHIT (3.4-5.8 h) was determined than for 4-phenyl-2-imidazolidinone (14.0-15.9 h). p-hydroxy-PTHIT (33%) and 4-phenyl-2-imidazolidinone (51%) were also detected in serum samples from cocaine users tested previously positive for PTHIT (n=73). Aminorex was never detected. The potential of misinterpreting 4-phenyl-2-imidazolidinone as aminorex was tested using a gas chromatography-mass spectrometry (GC-MS) method used in literature and an in-house liquid chromatography-time-of-flight mass spectrometry (LC-QTOF) screening-method. Using GC-MS the analysed bis-trimethylsilyl-derivatives cannot be differentiated due to co-elution. Both substances were chromatographically separated using the LC-QTOF method, but library comparison workflows misinterpreted 4-phenyl-2-imidazolidinone as aminorex. It seems likely that aminorex, which was allegedly identified as a metabolite of PTHIT in samples of cocaine users in previous studies, is in fact 4-phenyl-2-imidazolidinone.

Evaluation of a Delta-9-Tetrahydrocannabinol Carboxylic Acid (Δ9-THC-COOH) Immunoassay and a Gas Chromatography-Mass Spectrometry (GC-MS) Method for the Detection of Delta-8-Tetrahydrocannabinol Carboxylic Acid (Δ8-THC-COOH).

Delta-8 tetrahydrocannabinol (Δ8-THC) is a naturally occurring or synthetically prepared cannabinoid that elicits psychological and physiological experiences commonly reported for its more infamous isomer, delta-9 tetrahydrocannabinol (Δ9-THC). Unlike Δ9-THC, Δ8-THC products are generally legal under federal law and there has been a rise in their usage. One of the main targets for detection and quantitation of Δ9-THC is its inactive metabolite, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (Δ9-THC-COOH). This study evaluated the ability of the currently used Δ9-THC-COOH immunoassay and gas chromatography-mass spectrometry (GC-MS) methods to detect 11-nor-9-carboxy-Δ8-tetrahydrocannabinol (Δ8-THC-COOH) and distinguish it from Δ9-THC-COOH. The EMIT II Plus® Cannabinoid immunoassay for Δ9-THC-COOH with a cutoff of 20 ng/mL showed positive results for Δ8-THC-COOH with concentrations of 30 ng/mL or higher. Although many of the ion fragments generated by mass spectrometry were found to overlap between the 2 compounds, the GC-MS method presently used to quantify Δ9-THC-COOH separated the 2 compounds sufficiently to identify them independently by relative retention time. Current immunoassays and GC-MS methods should be evaluated for the ability to detect and distinguish the presence of Δ8-THC-COOH.

Overview of systematic toxicological analysis strategies and their coverage of substances in forensic toxicology.

Systematic toxicological analysis (STA) is the process of using an adequate analytical methodology to detect and identify as many potentially toxicologically relevant compounds as possible in biological samples. STA is an important part of everyday routine work within forensic toxicology, and several methods for STA have frequently been published and reviewed independently. However, the many drugs and other substances involved, as well as the constant emergence of new ones, may pose a major challenge in STA, which often demands a strategy involving multiple analytical methods in parallel. Such strategies have been published and evaluated less frequently despite their relevance in forensic toxicology. This mini-review briefly summarizes commonly applied methods for STA in forensic toxicology, including gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-MS (LC-MS) methods, and highlights some of their potential pitfalls. Second, it provides an overview of previously reported strategies to conduct STA, including a presentation of the STA strategy applied in the authors' laboratory. This involves broad drug screening by LC-high-resolution MS, supported by targeted screening and quantification using LC-tandem MS, headspace (HS)-GC-MS, HS-GC-flame ionization detector and other complementary methods. The STA strategy aims to cover as many potentially relevant drugs as possible and seeks to reduce potential pitfalls arising in forensic casework. The review underlines that not every substance can be identified in all circumstances even with a comprehensive STA strategy.

Chemical Composition, Antibacterial and Combinatorial Effects of the Essential Oils from Cymbopogon spp. and Mentha arvensis with Conventional Antibiotics

This work aimed to evaluate the chemical composition and antibacterial activity of essential oils of Cymbopogon citratus (CCEO), Cymbopogon khasianus (CKEO), and Mentha arvensis (MAEO) against two Gram-negative (Escherichia coli, Klebsiella pneumoniae) and three Gram-positive (Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis) microbial strains and their combination with antibiotics (chloramphenicol, ampicillin, erythromycin) to observe the synergistic behavior between them. The essential oils (EOs) were investigated by the GC-MS (gas chromatography mass spectrometry) method. The synergistic effect between EOs and antimicrobial agents was analyzed by broth dilution assay. (-)-carvone (52.48%), geraniol (57.66%), and citral (37.83%) were the major components identified in EOs of MAEO, CKEO, and CCEO, respectively. According to the antibacterial activity, EOs demonstrated strong antibacterial activity with MIC values ranging from 0.7 to 18 mg/mL. The interaction between the combination of EOs and antibiotics was determined in terms of FICI (Fractional Inhibitory Concentration Index). Some combinations displayed a partial synergistic effect, and some showed a synergistic and others displayed no effect against bacterial strains. The best synergistic action was shown by the combination of CCEO and Chloramphenicol against E. coli with a FICI value of 0.4. Three to four fold reductions in the MIC value of both essential oil and antibiotics were observed. Therefore, this synergistic interaction of the most active EOs with synthetic antibiotics could lead to new combination therapies for combating infections caused by multidrug-resistant microbes at sufficiently low concentrations in the pharmaceutical and food industry.

GC–MS analysis of soil faecal biomarkers uncovers mammalian species and the economic management of the archeological site "Le Colombare di Negrar"

The identification of the mammalian species based on faecal sediments in modern and ancient environments is the aim of the research of archaeologists, forensic scientists and ecologists. Here, we set up and validated an optimized gas chromatography-mass spectrometry (GC–MS) method, characterized by a time-saving sample preparation protocol, for the simultaneous analysis of faecal biomarkers (6 sterols/stanols and 5 bile acids) in 14 soil samples from the archaeological site of “Le Colombare di Negrar” in northern Italy. Although the archaeological sediment samples examined are numerically exiguous, a comparative reading of our faecal biomarkers findings with new studies on faunal materials collected in the same stratigraphic detail during recent excavation campaigns will allow to better clarify the economic interest of the animal species farmed in the Colombare site (such as bovines, goats, sheep and pigs) and to shed light on the management of breeding. Together with archaeozoological and archaeobotanical analyses, the investigation of faecal biomarkers can increase our knowledge of how ancient local communities exploited natural resources and may allow us to deduce what their impact on the landscape was.

Qualitative and quantitative studies of plasticizers in extra virgin olive oil by surface-enhanced Raman spectroscopy combined with chemometrics

Plasticizers are widely used as significant adjuvants in the plastics processing industry and have received widespread attention from the international community because of their reproductive toxicity. This study used a combination of surface-enhanced Raman spectroscopy (SERS) technology and chemometrics to conduct qualitative and quantitative analyses of plasticizers in extra virgin olive oil (EVOO). Among three established classification models, namely, partial least squares discriminant analysis (PLS-DA), k-nearest neighbours (KNN), and support vector machine (SVM), SVM was found to be the best classification model, with a correct classification rate (CCR) of 100 %. For the plasticizer concentration prediction model established by partial least squares (PLS), the absolute coefficient Rp2 was higher than 0.97, the root mean square error of prediction (RMSEP) was less than 3.632, and the ratio of performance to deviation (RPD) values were all greater than 5. Furthermore, the proposed method was validated by a standard gas chromatography-mass spectrometry (GC-MS) method using t-test with no significant difference. These results indicate that SERS combined with chemometrics can achieve the identification and quantification of plasticizers in EVOO and has application value for the analysis of plasticizers in edible oils.

Development of qualitative GC MS method for simultaneous identification of PM-CCM a modified illicit drugs preparation and its modern-day application in drug-facilitated crimes

Prescriptions for psychoactive substances such as Pregabalin, Methamphetamine, Caffeine, Clonazepam and Mirtazapine (PM-CCM) are common in the treatment of a variety of disorders. Indeed, the PM-CCM has been used in different therapeutic areas, including insomnia, anxiety, seizure disorders, etc. Unfortunately, these psychoactive substances are present in the illegal street market, leading to a lot of drug abuse among some addicted users, road insecurity and suicide. Hence, it has become essential to validate and develop a rapid and effective method to analyze the PM-CCM, a modified illicit drug, for drug abuse in the forensic sciences. A simple, rapid, specific and sensitive Gas Chromatography-Mass Spectrometry(GC-MS) method has been developed for the identification of Pregabalin, Methamphetamine, Caffeine, Clonazepam and Mirtazapine (PM-CCM) in forensic exhibits. At room temperature, the sample was ultrasonicated for 5 minutes before being extracted with methanol. A highly precise auto-injector is used to inject a very small quantity of samples for analysis. Helium is used as a carrier gas with a flow rate of 1 ml/min. The separation of PM-CCM was performed on SH-RXi-5 MS, ID.25 mm, film thickness. 25 µm, length of 30 m column. The constituents of PM-CCM were identified by the mass-to-charge ratio (m/z ratio) of fragments of the parent compound by comparing them with the NIST-17 MS Library. Separation and identification of PM-CCM were achieved within a 15-minute run. The proposed method has been successfully used for the routine analysis of PM-CCM in complex illicit drug preparations and in forensic exhibits as well. The application of above discussed qualitative analysis method and screening of PM-CCM, modified illicit drug samples demonstrates the potential and applicability of the technique to the fast chemical profiling of illicit samples.

Pesticide residues in rice planted in South and Southwest China

ABSTRACT In 2019 and 2020, 70 paddy and 70 brown rice samples were collected from South China and Southwest China, wherein the residues of 15 target pesticides were investigated. A gas chromatography-mass spectrometry (GC-MS) method was established for the simultaneous detection of 15 pesticides, which achieved good linear relationship with limits of detection (LODs) of 0.10–4.00 μg kg−1. The average recoveries and relative standard deviations (RSD) were satisfied for the pesticide residues detection. Analysis results showed that the detection rates of 15 typical pesticides in paddy and brown rice were 0%-12.9% and 0%-1.4%, respectively. None of the 15 pesticides exceed their maximum residue limit (MRL) stipulated by China. The pesticide with the highest detection rate and concentration was chlorpyrifos. This study can provide data support for the control of pesticide residues in rice and the realisation of the improving the efficiency of pesticide and fertiliser while reducing their application.

Komponen Kimia Minyak Atsiri yang Diisolasi dari Daun Tanaman Pucuk Merah (Syzygium myrtifolium Walp.) dan Potensi Antibakteri serta Toksisitasnya

Pucuk merah (Syzygium myrtifolium Walp.) is an ornamental plant from the Myrtaceae family. Several phytochemical tests from previous researchers reported that pucuk merah contains secondary metabolites that have benefits such as antioxidants, antibacterials, and anti-cancer. In addition, the distinctive aroma produced from pucuk merah leaves indicates the presence of essential oils whose bioactivity can be studied. Still, there has been no report on this plant's chemical components or bioactivity. Therefore, this study aims to determine the content of chemical components of pucuk merah essential oil and their bioactivity as antibacterial and toxicity. The isolation of essential oils was carried out by the hydro distillation method. The chemical components of essential oils were analyzed using the Gas Chromatography-Mass Spectrometry (GC-MS) method. GC-MS results showed the presence of 42 compounds with four main compounds, namely caryophyllene (23.45%), 3-carene (15.67%), α-terpineol (10.74%), and α-pinene (5.98%) ). Antibacterial test of pucuk merah essential oil using the disc diffusion method showed strong activity against Staphylococcus aureus and Escherichia coli with inhibition zones of 16.15 ± 2.03 and 16.13 ± 1.74 mm at 100% concentration. The results of the toxicity test of pucuk merah essential oil using the BSLT (Brine Shrimp Lethality Test) method on Artemia salina Leach shrimp larvae showed strong toxic properties with an LC50 value of 3.99 µg/mL.

Quantification and stability assessment of urinary phenolic and acidic biomarkers of non-persistent chemicals using the SPE-GC/MS/MS method

Nowadays, people are exposed to numerous man-made chemicals, many of which are ubiquitously present in our daily lives, and some of which can be hazardous to human health. Human biomonitoring plays an important role in exposure assessment, but complex exposure evaluation requires suitable tools. Therefore, routine analytical methods are needed to determine several biomarkers simultaneously. The aim of this study was to develop an analytical method for quantification and stability testing of 26 phenolic and acidic biomarkers of selected environmental pollutants (e.g., bisphenols, parabens, pesticide metabolites) in human urine. For this purpose, a solid-phase extraction coupled with gas chromatography and tandem mass spectrometry (SPE-GC/MS/MS) method was developed and validated. After enzymatic hydrolysis, urine samples were extracted using Bond Elut Plexa sorbent, and prior to GC, the analytes were derivatized with N-trimethylsilyl-N-methyl trifluoroacetamide (MSTFA). Matrix-matched calibration curves were linear in the range of 0.1–1000 ng mL−1 with R > 0.985. Satisfactory accuracy (78–118%), precision (< 17%), and limits of quantification (0.1–0.5 ng mL−1) were obtained for 22 biomarkers. The stability of the biomarkers in urine was assayed under different temperature and time conditions that included freezing and thawing cycles. All tested biomarkers were stable at room temperature for 24 h, at 4 °C for 7 days, and at −20 °C for 18 months. The total concentration of 1-naphthol decreased by 25% after the first freeze–thaw cycle. The method was successfully used for the quantification of target biomarkers in 38 urine samples.

Physicochemical Characteristics, Antioxidant and Antibacterial Activities of Liquid Smoke Derived from Mixed Sawdust and Cocoa Pod Husks Biomass

This study aimed to analyze the physicochemical characteristics, antioxidant and antibacterial activities of liquid smoke derived from mixed sawdust (MS) and cocoa pod husks (CPH) biomass. The liquid smoke formed by pyrolysis of MS and CPH biomass (Theobroma cacao L.) has the physical characteristics of brown color, transparrent, has floating solids, and has an acidic pH of 3.79 for MS and 5.43 for CPH. The results of the antibacterial assay of both liquid smokes by agar diffusion method against 3 pathogenic bacterial isolates; Escherichia coli FNCC 0091, Staphylococcus aureus FNCC 0047 and Salmonella typhimurium FNCC 0150 showed positive results with the formation of clear zones around the test discs. Antioxidant activity assay showed that liquid smoke derived from the biomass of MS had an IC50 value of 0.112 mg/mL, more potential than liquid smoke derived from the biomass of CPH, which was 2.060 mg/mL. Liquid smoke chemical composition analyzed by Gas Chromatography-Mass Spectrometry method showed that liquid smoke derived from MS biomass was dominated by acetic acid (64.64 %), phenols (12.08 %) and acetone (5.78 %), while the liquid smoke derived from CPH biomass was dominated by methylamine (37.26 %), acetic acid (24.61 %) and acetone (19.89 %). The acetic acid, phenols, methylamine and acetone content in both liquid smokes thought to play an important role on its antioxidant activities and inhibition of bacterial growth. HIGHLIGHTS Pyrolysis uses biomass as raw material in the form of mixed sawdust from the home furniture industry and CPH which are a by-product of the chocolate processing industry The liquid smoke obtained from the pyrolysis of both types of biomass has a unique composition and has antibacterial and antioxidant properties The liquid smoke has the potential to be applied as a preservative in food products GRAPHICAL ABSTRACT

Development and Validation of a Gas Chromatography-Mass Spectrometry Method for Determining Acaricides in Bee Pollen.

Pesticides can be found in beehives for several reasons, including contamination from surrounding crops or for their use by beekeepers, which poses a risk to bee ecosystems and consumers. Therefore, efficient and sensitive methods are needed for determining pesticide residues in bee products. In this study, a new analytical method has been developed and validated to determine seven acaricides (atrazine, chlorpyrifos, chlorfenvinphos, α-endosulfan, bromopropylate, coumaphos, and τ-fluvalinate) in bee pollen using gas chromatography coupled to mass spectrometry. After an optimization study, the best sample treatment was obtained when using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method employing an ethyl acetate and cyclohexane as the extractant mixture, and a mixture of salts for the clean-up step. A chromatographic analysis (<21 min) was performed in an Agilent DB-5MS column, and it was operated under programmed temperature conditions. The method was fully validated in terms of selectivity, limits of detection (0.2-3.1 µg kg-1) and quantification (0.6-9.7 µg kg-1), linearity, matrix effect (<20% in all cases), trueness (recoveries between 80% and 108%), and precision. Finally, the proposed method was applied to analyze commercial bee pollen samples, and some of the target pesticides (chlorfenvinphos, α-endosulfan, coumaphos, and τ-fluvalinate) were detected.

Chemical Composition and Antibacterial Activity of Wild Rose (Rosa canina L.) Gall Extracts against Gram-Negative Pathogenic Bacteria

Background &amp; Objectives: Treating infections due to antibiotic-resistant bacteria is a challenge and researchers are looking for new antimicrobial compounds. Galls are abnormal plant growths caused by biological agents and have active compounds. The present study was designed to examine the antibacterial effects of different extracts of wild rose gall (Rosa canina L.) against some pathogenic Gram-negative bacilli.&#x0D; Materials &amp; Methods: Methanol, acetone, and aqueous extracts from galls were prepared using Soxhlet apparatus. The antibacterial activity of the extracts was determined by agar well diffusion method, and the minimum inhibitory concentration and the minimum bactericidal concentration were assessed by the microdilution method. The phytochemical composition of galls was investigated by Gas Chromatography-Mass Spectrometry (GC-MS) method.&#x0D; Results: The inhibition zones of 500 mg/mL methanol extract of wild rose gall against Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Klebsiella pneumoniae, Acinetobacter bummani, Shigella sonei, and Salmonella typhi were 26.7, 25.0, 25.7, 25.7, 26.7, 23.7 and 18.3, respectively. The antimicrobial activity of the extracts was directly related to their concentration. The extracts were active against all the pathogenic bacteria with average MICs ranging from 15.6 to 31.3 mg/mL. The methanol extract of wild rose gall showed the highest bactericidal effect on P. aeruginosa and A. bummani at 62.5 mg/mL, respectively. Moreover, oleic acid, palmitic acid, and octadecenoic acid were composed 36.66%, 14.40%, and 13.21% of total active compounds in wild rose gall.&#x0D; Conclusion: All of the wild rose gall extracts showed significant antibacterial activities against Gram-negative bacilli. The antibacterial effects may be related to the high amounts of organic acids in wild rose gall extracts.&#x0D;

Lindera Essential Oils from Vietnam: Antimicrobial Activity and Constituents of the Leaf of Lindera chunii Merr. (Lauraceae) Essential Oils and Chemotaxonomy

Lindera chunii Merr. is an important member of the Lauraceae family of plants which are known for their medicinal values. In this research article, the chemical constituents and antimicrobial activity of essential oils from the leaves of L. chunii grown in Vietnam were reported. The essential oil was obtained by hydrodistillation of the leaves of L. chunii while the constituents were determined by using gas chromatography (GC) and gas chromatography-mass (GC/MS) spectrometry methods. The antimicrobial activity was evaluated using a microdilution broth susceptibility assay. The constituents occurring in higher amounts in the leaf essential oil of L. chunii were mainly the monoterpene hydrocarbons comprising terpinolene (13.0%), α-pinene (8.0%), β-pinene (7.6%), camphene (7.3%), β-phellandrene (7.1%) and myrcene (5.0%). The leaf essential oil of L. chunii inhibited the growth of Enterococcus faecalis ATCC29212, Staphylococcus aureus ATCC25923 and Salmonella enterica ATCC13076, each with minimum inhibitory concentration (MIC) value of 64.0 μg/mL. The corresponding median lethal concentration (IC50) values were 19.45 μg/mL, 20.45 μg/mL and 18.78 μg/mL, respectively. The essential oil also displayed anti-candidal activity towards Candida albicans ATCC10231 with MIC value of 64.0 μg/mL, and IC50 value of 23.12 μg/mL. The antimicrobial activity of L. chunii essential oil was reported for the first time as a confirmation of the traditional uses of the plant in the treatment of microbial infections. Furthermore, the paper discusses the chemotaxonomy of Lindera oil samples.