GC-MS Method Research Articles

Simultaneous determination of low molecular weight nitrosamines in pharmaceutical products by fast gas chromatography mass spectrometry

Control of N-nitrosamines has been in the focus of health authorities in recent years because many of these compounds are probable human carcinogens. In July 2018 the U.S. Food and Drug Administration (FDA) announced a recall for valsartan-containing medicines due to contamination with the carcinogenic low molecular weight nitrosamine, N-nitrosodimethylamine (NDMA). It has become clear that the problem can not only exist in the case of sartans, but in any active pharmaceutical ingredient (API)/drug product in which secondary or tertiary amines are present (as API or as impurities) and a nitrosating agent is available. The decision was made by regulators, according to which manufacturers of pharmaceutical products are obliged to perform a risk assessment for the potential presence of nitrosamines in active pharmaceutical ingredients and drug products. This resulted in a high demand for validated analytical methods that are able to quantify N-nitrosamines at low ppb levels in pharmaceutical products.In this work we have developed and validated a generic fast GC-MS method suitable for the quantitative determination of a wide range of low molecular weight nitrosamines, which include N-nitrosodiethylamine (NDEA), N-nitrosodimethylamine (NDMA), N-nitroso-diphenylamine (NDPh), N-nitrosodipropylamine (NDPA), N-nitrosomethylethylamine (NMEA), N-nitrosomorpholine (NMOR), N-nitrosopiperidine (NPIP), N-nitroso-ethylisopropylamine (EIPNA), N-nitroso-diisopropylamine (DIPNA), N-nitroso-N-methylaniline (NMPA), 1-Methyl-4-nitrosopiperazine (MeNP) and N-nitroso-pyrrolidine (NPYR). The advantage of the method is that it is possible to screen low molecular weight nitrosamines in low concentrations with a short analysis time in a wide range of APIs and drug products.

Effect of Wort Boiling System and Hopping Regime on Wort and Beer Stale-Flavor Aldehydes.

The main factor responsible for the sensory aging of beer is the increase in off-flavor aldehydes during beer storage. In pilot brews (200 L) of pale lager beer with different hopping regimes and wort boiling systems, 15 carbonyls were monitored using the GC-MS method. Factor analysis revealed several groups of aldehydes with similar behavior during wort boiling. The concentration of most of them decreased with atmospheric wort boiling and increased with the time and energy-saving pressurized boiling system. Wort clarification was a critical step because of the increase in carbonyl concentration, with the level of most carbonyls being higher in the final wort compared to sweet wort. The hopping regimes only affected the level of 3-methylbutan-2-one in the wort. The concentration of carbonyls decreased significantly (30-90%) during fermentation, except for trans-2-butenal, which increased by 59% on average, likely due to the release from imine complex. The concentration of free aldehydes in the fresh beers was similar for all variants used, but the pressurized wort boiling system could result in lower sensory stability of the beer due to the release of aldehydes from inactive complexes formed during fermentation. This aspect requires further investigation.

Identification and characterization of TMV-induced volatile signals in Nicotiana benthamiana: evidence for JA/ET defense pathway priming in congeneric neighbors via airborne (E)-2-octenal

Plants release a mixture of volatile compounds when subjects to environmental stress, allowing them to transmit information to neighboring plants. Here, we find that Nicotiana benthamiana plants infected with tobacco mosaic virus (TMV) induces defense responses in neighboring congeners. Analytical screening of volatiles from N. benthamiana at 7 days post inoculation (dpi) using an optimized SPME–GC–MS method showed that TMV triggers the release of several volatiles, such as (E)-2-octenal, 6-methyl-5-hepten-2-one, and geranylacetone. Exposure to (E)-2-octenal enhances the resistance of N. benthamiana plants to TMV and triggers the immune system with upregulation of pathogenesis-related genes, such as NbPR1a, NbPR1b, NbPR2, and NbNPR1, which are related to TMV resistance. Furthermore, (E)-2-octenal upregulates jasmonic acid (JA) that levels up to 400-fold in recipient N. benthamiana plants and significantly affects the expression pattern of key genes in the JA/ET signaling pathway, such as NbMYC2, NbERF1, and NbPDF1.2, while the salicylic acid (SA) level is not significantly affected. Our results show for the first time that the volatile (E)-2-octenal primes the JA/ET pathway and then activates immune responses, ultimately leading to enhanced TMV resistance in adjacent N. benthamiana plants. These findings provide new insights into the role of airborne compounds in virus-induced interplant interactions.

Chemical Compositions of Essential Oil of Agarwood <i>(Aquilaria crassna)</i> Harvested in Phu Quoc Island, Vietnam

The importance of natural products derived from Agarwood species is increasingly emphasized in the production of perfumery or cosmetic products made on Agarwood species. On the other hand, due to the predominant amount of aromatic compounds in essential oils, frankincense essential oil is increasingly popular with high economic value. Therefore, in this study, we focused on the extraction process of essential oils and evaluated the chemical composition present in the essential oils by the GC-MS method. Differences in the composition of essential oils between natural and artificial agarwood may be due to species, habitat conditions, climate, geographical conditions, and extraction methods in different regions. Specifically, volatile components in essential oils were identified as Neopetasone (14.43%); Dihydroagarofuran-15-al (9.20%); Jinko-cramol (5.02%); Valeriano (4.94%); Agarofuran <b-> (8.02%); Dihydrokaranone (3.25%), Valenca-1 (10), 8-dien-11-ol (5.95%) and Selina-4,11-dien-14-al (2.73%), contribute to determining the main aroma in Agarwood essential oil.

Content, Distribution, Source Analysis, and Risk Assessment of PAHs in Arable Soils of Taiyuan

PAHs (polycyclic aromatic hydrocarbons) accumulated in arable soils have significant impacts on farmland quality and human health, which has attracted wide attention from scientists and the public. A total of 22 arable soil samples were collected from Taiyuan, an old industrial city, including three districts (industrial zones, hilly areas, and sewage irrigation area), and the contents of 21 PAHs were detected using the GC-MS method. The sources of PAHs in soils were analyzed using the diagnostic ratios (DRs) method and positive matrix factorization (PMF) model, and the soil health risks were analyzed using the incremental lifetime cancer risk (ILCR) model. The results indicated that the average concentrations of Σ21PAHs and Σ16PAHs in arable soils of Taiyuan were 934.6 ng·g-1 and 787.7 ng·g-1, respectively, which were lower than the soil pollution risk screening value of agricultural land stipulated in GB 15168-2018. 3-5 rings PAHs were the dominant components, accounting for~90% of the Σ21PAHs. Approximately 60% of sites in industrial zones, 13% in hilly areas, and 33% in the sewage irrigation area had high PAHs contents larger than 1000 ng·g-1. The spatial distribution of PAHs showed that more severe PAHs pollution in the soil occurred in industrial areas than that in the other two districts. The DRs suggested that the combustion of coals, bio-masses, and traffic emissions were the dominant sources for PAHs pollution in arable soils in Taiyuan. The simulation results of the PMF model indicated that the sources and contribution rates of PAHs in cultivated soils were coal and biomass burning sources (59%), traffic sources (22%), and coking sources (19%). The risk assessment confirmed that the arable soils in Taiyuan had high potential carcinogenic risks; thus, more attention should be paid to the PAHs pollutions in arable soils.

Assessing the environmental and overall performance of gas chromatographic analyses. Development of a comprehensive evaluation framework and application to routine chiral analyses of fragrances as a case study

Enantioselective gas chromatography is used in fragrance quality control laboratories to authenticate the origin of raw materials and detect possible frauds or adulterations of perfumes. These laboratories must contend with increasing attention to environmental sustainability, quality standards that require accurate and reliable measurements, and practical considerations such as productivity, costs, and simplicity of methods. Quantitative tools enabling a global evaluation of all these aspects are therefore required. In the first part of the study, a GC-MS method for the chiral recognition of a set of odorants was developed and speeded up. The improvement in environmental footprint associated with fast GC was then quantitatively evaluated using AGREE. This tool allowed a rapid comparison of environmental impacts between different analytical methods, but, despite a very different energy consumption, showed few differences in the final score of the developed methods. Therefore, a multi-criteria approach based on the RGB model, for the first time specifically dedicated to GC analytical methods, was developed. It accurately accounts for the contribution of GC and the need to limit the consumption of energy and toxic solvents while maintaining analytical performance and adequate laboratory productivity. The template can be adapted to analyses with a different scope by changing the analytical performance criteria and the reference threshold of the method. The global assessment of the methods developed showed that fast GC improves the greenness and the productivity of a laboratory, and lowers costs while maintaining adequate analytical performance making the approach not only green but also sustainable.

Antibacterial and antioxidant activity of sea cucumber extracts collected from Lampung waters, Indonesia

Sea cucumbers are the most prevalent marine invertebrates in Indonesian waters, yet little research has been conducted on the bioactive substances found in the sea cucumbers harvested from these waters. To investigate the potential use of sea cucumber extracts and fractions such as antibacterial and antioxidant agents, five sea cucumber species were harvested from Lampung waters in Indonesia. The extraction process used the maceration method with methanol solvent, while fractionation was carried out with n-hexane, ethyl acetate, and butanol solvents. The antibacterial activity was evaluated using the agar diffusion method, and the antioxidant activity was assessed using the ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) method. The GC–MS method was used to identify the compounds in the methanol extract and butanol fraction of Holothuria lessoni. The results showed that only the n-hexane fraction of Stichopus quadrifasciatus and the methanol extract of H. lessoni had antibacterial activity against Propionibacterium acnes, while the methanol extract of H. lessoni and the ethyl acetate fraction of H. leucospilota showed activity against Staphylococcus aureus. The n-hexane fraction of S. quadrifasciatus and the methanol extract of H. lessoni and Bohadschia marmorata recorded activity against Staphylococcus epidermidis. Among the tested extracts, Holothuria leucospilota showed the highest antioxidant activity in methanol extracts, with an IC50 value of 155.07 ​± ​3.05 ​μg/mL, followed by H. lessoni (163.83 ​± ​4.46 ​μg/mL), Stichopus vastus (209.45 ​± ​2.40 ​μg/mL), S. quadrifasciatus (245.85 ​± ​34.97 ​μg/mL), and B. marmorata (382.86 ​± ​45.37 ​μg/mL), respectively. Cyclononasiloxane, octadecamethyl- (C18H54O9Si9), cyclohexasiloxane, dodecamethyl (C12H36O6Si), and cyclooctasiloxane, hexadecamethyl- (C16H48O8Si8) were identified as the main compounds in the tested samples using GC–MS analysis. In conclusion, H. lessoni is a valuable source of natural antibacterial and antioxidant agents.

A Review on Capsaicin-Methods of Extraction, Estimation and Therapeutic Effects

The capsaicin alkaloid is the secondary metabolite present in the fruits of Capsicum annum, which belongs to the family Solanaceae. Capsaicin and dihydrocapsaicin constitute 50% of the capsaicinoids in Capsicum annum. The present article describes methods for extracting Capsaicin, like soxhlation, microwave-assisted extraction(MAE), ultrasonication, and supercritical fluid extraction. Also, different analytical methods for estimating Capsaicin are specified, including spectroscopic and chromatographic methods and hyphenated techniques, and the best approach is described. Microwave-assisted extraction of Capsaicin at a temperature of 120ºC and the solid-liquid ratio of 25mg/mL for 90 min yields 3.85% of Capsaicin, the most suitable and easy method for extracting Capsaicin. The best way for estimating Capsaicin is to use a GC-MS method with EI ionization at 70 eV and a column of 5% diphenyl, 95% dimethylpolysiloxane, 30 m x 0.25 mm, using helium as the mobile phase at a flow rate of 1.61 mL/min at a column temperature of 60ºC and injector temperature of 250ºC. Capsaicin has many pharmacological effects like anti-cancer, antidiabetic, antioxidant, antimicrobial, etc., which are also discussed in this article.

Chemical and Toxicological Diagnosis of Acute Poisoning with Doxylamine, Zaleplon, and Phenazepam

BACKGROUND The market of hypnotic and sedative drugs is being updated due to the high toxicity of barbiturates and the limitations of their use. Currently, safer drugs such as Z-drugs, Doxylamine, and some benzodiazepine derivatives are often prescribed for the treatment of anxiety and insomnia, but they can cause acute poisoning if overdosed or in case of nonmedical use.AIM To establish an affordable express thin-layer chromatography (TLC) technique for preliminary screening detection of Doxylamine, Phenazepam and Zaleplon in order to diagnose acute poisoning.MATERIAL AND METHODS Thin-layer chromatography (TLC) and gas chromatography with mass selective detection (GC-MS) methods were used. Urine samples from patients with symptoms of acute Doxylamine, Zaleplon, Phenazepam poisoning, and model urine samples were prepared by liquid-liquid extraction at pH 9.0 with chloroform for TLC analysis, with ethyl acetate-diethyl ether mixture (1:1) for GC-MS.RESULTS We developed the TLC method of Doxylamine, Zaleplon and Phenazepam detection which helps reveal their presence in the patient’s urine, as well as distinguish one from another in case of similar toxic symptoms. The GC-MS method was used for confirmatory analysis. Compared to confirmatory methods, the developed technique of TLC screening is expressive, does not require expensive high-tech equipment, while allowing to differentiate Doxylamine, Zaleplon and Phenazepam from each other and from other toxicologically significant psychoactive substances detected in general screening.

An innovative solid-phase biosensor for rapid on-site detection of N-nitrosodimethylamine incorporating zein film and upconversion nanoparticles

Pickled frequently contains nitrosodimethylamine (NDMA), a mutagenic and carcinogenic substance that is dangerous for the general public's health. This study reports on the fabrication of a fluorescent biosensor using zein film and aptamer functionalized upconversion nanoparticles (UCNPs) for on-site monitoring of NDMA in meat. UCNPs were first prepared followed by aptamer binding and mixing with zein film, which was further conjugated with cDNA of dabcyl modified at 5′. The fluorescence resonance energy transfer (FRET) mechanism between the UCNPs and dabcyl was exploited. The fluorescence signals of the zein film recovered when NDMA was present because it was selectively collected by the particular aptamer and damaged the cDNA structure. The designed functionalized zein film was used for on-site and portable determination of NDMA with a lower limit of detection of 0.017 ng/mL, and possessed a satisfactory recovery ranging from 95.8% to 100.2% with no significant difference compared with the GC–MS method.

Transformations of 2-(1-chloroethenyl)naphthalene in the presence of pd(0) nanoparticles on a glass substrate

Homo-and cross-coupling products were obtained in an attempt to obtain 2-ethynylnaphthalene from 2-(1-chloroethenyl)maphthalene in a glass reactor contaminated with palladium black nanoparticles on the inner wall. The structure of reaction products was characterized by the GC-MS method.

Assessment of total glycerol core aldehyde and monomer content based on NIR and PLS

Glycerol core aldehydes (GCAs) are non-volatile aldehydes residing in frying oil. In this study, near-infrared spectrum (NIR) was used in conjunction with partial least squares (PLS) to create a model for quantifying the total and monomeric content of GCAs. The total and monomer GCAs content in high oleic sunflower oil determined by the GC-MS method was used to assess the model's prediction accuracy. After comparison, the optimal spectrum ranges for both total GCAs and GCAs (9-oxo, 10-oxo-8, and 11-oxo-9) were 8800–6600 cm−1, and the optimal spectrum range for GCAs (8-oxo) was 7420–6600 cm−1. The optimal preprocessing for total GCAs and GCAs (8-oxo, 9-oxo, 10-oxo-8, and 11-oxo-9) were first derivative spectrum, first derivative, original spectrum, first derivative spectrum + NDF smoothing, and first - derivative spectrum + S-G smoothing, respectively. The results demonstrated that the NIR-PLS model had good predictive ability, and the coefficients of determination (R2) for total GCAs and four monomers in the proposed quantitative analysis models were 0.9772, 0.9383, 0.9688, 0.9674, and 0.9745, respectively, and the relative root means square errors of prediction (RMSEP) were 0.0362, 0.0071, 0.0300, 0.0034, 0.0043, and can be predicted quickly and nondestructively, non-toxic, and easy to operate and use.

Investigation of the relationship between nicotine and cotinine concentrations in human biological samples by a GC-MS method

In this study, a gas chromatography-mass spectrometry method was developed for the determination of nicotine and cotinine wherein human plasma, urine, and saliva. In addition, it was aimed to determine statistically the correlation between nicotine and cotinine levels in urine and saliva samples and nicotine and cotinine levels in blood samples. The limit of quantification was ≤0.83 ng/mL and precision were ≤4.91 and accuracy (RE%) was between (-4.93) and 4.90. Recovery was detected between 95.4% and 104.7%. The method was employed to determining the nicotine and cotinine concentrations in plasma, saliva, and urine total of 91 samples belong to non-smokers (n=37) and active smokers (n=54) who were healthy (n=65) and COPD patients (n=27) and the statistical relationship within the nicotine and cotinine values of the samples were investigated. It was found a correlation (r=0.752, p≤0.01) between plasma and saliva cotinine levels and estimation equation calculated as y=1.56x+43.24. Also, the correlation between plasma and urine cotinine levels was found (r=0.787, p≤0.01) by the equation that y=0.31x+34.59. The results show that by accurately determining the amount of cotinine in both saliva and urine, the exposure risks of both active smokers and those exposed to cigarette smoke with the ETS can be estimated.

Thermal Extraction: An Alternative Headspace GC–MS Method for Volatile Extractables from Medical Device Materials

Thermal Extraction: An Alternative Headspace GC–MS Method for Volatile Extractables from Medical Device Materials

Caffeoyl-coenzyme A O-methyltransferase mediates regulation of carbon flux fluctuations during phenylpropenes and lignin biosynthesis in the vegetative organ roots of Asarum sieboldii Miq

Asarum sieboldii Miq. possesses remarkable medicinal value due to its essential oil enriched with phenylpropenes (e.g., methyleugenol and safrole). Although the biosynthesis of phenylpropenes shares a common pathway with lignin, the regulation mechanisms in carbon flux allocation between them are unclear. This study is the first to genetically verify the carbon flux regulation mechanism in A. sieboldii roots. We regulated the expression of Caffeoyl-coenzyme A O-methyltransferase (CCoAOMT), an essential enzyme in the common pathway, to investigate carbon flux allocation in vegetative organs. Here, the lignin and phenylpropene content fluctuation was analyzed by wet chemistry and GC-MS methods. A bona fide CCoAOMT gene from A. sieboldii was firstly cloned and verified. Preliminary heterologous expression validation in transgenic Arabidopsis thaliana showed that RNAi-induced CCoAOMT down-regulation significantly decreased lignin content by 24% and increased the S/G ratio by 30%; however, AsCCoAOMT over-expression in A. thaliana resulted in a 40% increase in lignin content and a 20% decrease in the S/G ratio when compared to the wild type. Similar trends were noted in homologous transformation in A. sieboldii, although the variations were not conspicuous. Nevertheless, the transgenic A. sieboldii plants displayed substantial differences in the level of phenylpropene compounds methyleugenol and safrole leading to a 168% increase in the methyleugenol/safrole ratio in the over-expression line and a 73% reduction in RNAi-suppression line. These findings suggest that the biosynthesis of phenylpropene constituents methyleugenol and safrole seems to be prioritized over lignin. Furthermore, this study indicated that suppression of AsCCoAOMT resulted in marked root susceptibility to pathogenic fungal disease, implying a significant additional role of CCoAOMT in protecting plant vegetative parts from diseases. Overall, the present study provides important references and suggests that future research should be aimed at elucidating the detailed mechanisms of the carbon flux allocation between phenylpropenes and lignin biosynthesis, as well as the disease resistance competency.

P26-019-23 Robust and Improved GCMS Method for the Simultaneous Analysis of Diverse Fatty Acids in Large Cohorts

P26-019-23 Robust and Improved GCMS Method for the Simultaneous Analysis of Diverse Fatty Acids in Large Cohorts

Study of the qualitative composition of phenolic compounds in underground organs of Eleutherococcus senticosus (Rupr. et Maxim.) by GC-MS method

Study of the qualitative composition of phenolic compounds in underground organs of Eleutherococcus senticosus (Rupr. et Maxim.) by GC-MS method

Effectivity of Inhibition of Oil Palm Empty Fruit Bunches Liquid Smoke Against Ganoderma boninense Fungus In Vitro

Oil palm empty fruit bunches (OPEFB) can be processed into liquid smoke through pyrolysis. This study aimed to obtain the best concentration of unpurified liquid smoke from OPEFB in inhibiting the growth of the fungus of Ganoderma boninense. OPEFB samples were obtained from PT. Citra Putra Kebun Asri and G. boninense were collected from Muara Teweh Plantation. The study was conducted in 2 stages; Analysis of liquid smoke from pyrolysis using the GC-MS method at the Organic Chemistry Laboratory, Faculty of Mathematics and Natural Sciences, Gadjah Mada University; and testing the inhibition of liquid smoke on G. boninense in vitro at the Basic Plantation Cultivation Laboratory, Hasnur Polytechnic, and the Microbiology Laboratory of Plantation Products Processing Technology, Muara Teweh Polytechnic. This study was conducted in a completely randomized design with four treatments and six replications. The treatment was the difference in concentration of liquid smoke (1 ml/AC1, 2 ml/AC2, 3 ml/AC3, and control/AC0) in the planting medium, potato dextrose agar (PDA). The results showed that the average yield of unpurified liquid smoke from OPEFB was 34.5%, containing 49.28% acetic acid, 11.57% methyl alcohol, and 9.10% phenol. Application ? 2 ml liquid smoke in PDA completely inhibited G.boninense's growth in vitro, starting three days after application.

GC-FID and GC-MS detection of Ethyl Isobutyryl Acetate as regulatory starting material

We developed GC-FID and GC-MS methods to determine the assay and chromatographic purity of Ethyl isobutyryl acetate (EIBA). The symmetric peak shape was on a DB-Wax stationary phase with the dimensions of 30 m column length, 0.25 mm as internal diameter, 0.50 microns film thickness with the mobile phase as helium gas in temperature ramping mode at a flow rate of 1.5 mL/min using flame ionization detector and mass spectrometer. The USP resolution between EIBA and its unknown impurities was more than 2.0, indicating a significant separation. Regression analysis shows a correlation coefficient greater than 0.999 for EIBA assay and chromatographic purity techniques. The detection and quantitation limits of EIBA are 0.01% and 0.03% for the chromatographic purity procedure. This method indicates that the recovery at different levels is 90 to 110% accurate. The test solution was stable in the diluent for 48 h and subjected to stress conditions. The mass balance was close to 99.5%.

The antisickling effect of stem extracts of Costus afer

This research was geared towards investigating the antisickling effect of stem extracts of Costus afer. The antisickling effect of the stem extracts of Costus afer was investigated to determine and declare its potentiation. This work was approached by partitioning the extracts of Costus afer stem into; stem fat-soluble fraction (SFSF), stem ethanol-soluble fraction (SESF) and stem methanol-soluble fraction (SMSF). The phytochemical screening was qualitatively and quantitatively determined using standard GC-MS methods. The result shows the presence of twenty (20) different secondary metabolites with a wide range of functions. The amino acid profiles of the extracts revealed the presence of Phenylalanine, Arginine, Lysine, Serine, Methionine and others. Haemoglobin polymerization inhibition and the relative percent inhibition were estimated. The ethanol-soluble fraction (SESF), methanol-soluble fraction (SMSF) and fat-soluble fractions (SFSF) are 74.68 % ±0.00, 26.58 % ±0.00 and 22.78 % ±0.00 inhibition on HbSS polymerization, respectively. The percent improvement on Fe2+/Fe3+ ratio are: 96.64 ± 0.12, 66.14 ± 0.11 and 47.24 ± 0.03 for the fat-soluble fraction, methanol-soluble fraction and ethanol-soluble fractions, respectively. The total free amino acid values range from 776.15 ± 2.15 mg/50 g for the SMSF to 1,188.00 ±12.12 mg/50 g for the SFSF. The total vitamin C concentration of the samples expressed in mg/100 g is 297.59 ± 33.26. The results of this work show that stem extracts of Costus afer can be effectively used as phytomedical therapy for sickle cell disease management.