Search results for "Gas chromatography–mass spectrometry"
showing 10 items of 199 documents
Exposure assessment approach through mycotoxin/creatinine ratio evaluation in urine by GC–MS/MS
2014
Abstract In this pilot survey human urine samples were analyzed for presence of 15 mycotoxins and some of their metabolites using a novel urinary multi-mycotoxin GC–MS/MS method following salting-out liquid–liquid extraction. Fifty-four urine samples from children and adults residents in Valencia were analyzed for presence of urinary mycotoxin and expressed in gram of creatinine. Three out of 15 mycotoxins were detected namely, HT-2 toxin, nivalenol and deoxynivalenol (DON). 37 samples showed quantifiable values of mycotoxins. Co-occurrence of these contaminants was also observed in 20.4% of assayed samples. DON was the most frequently detected mycotoxin (68.5%) with mean levels of 23.3 μg/…
Biomonitoring of Multiple Mycotoxins in Urine by GC–MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran
2021
A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON
Application of time-of-flight aerosol mass spectrometry for the online measurement of gaseous molecular iodine.
2012
Here we present a new application of a time-of-flight aerosol mass spectrometer (TOF-AMS) for the measurement of atmospheric trace gases in real-time. Usually, TOF-AMS instruments are not sensitive to gas-phase species due to the aerodynamic particle focusing inlet system which reduces the gas phase species by a factor of about 10(7) relative to the particle phase. This efficient removal of the gas phase and the resulting high relative enrichment of particles is one reason for the very high sensitivity of TOF-AMS instruments for particle phase compounds (detection limits in the sub-μg/m(3)-range for online measurements with 1 min integration time), which allows application of the instrument…
Aroma release in the oral cavity after wine intake is influenced by wine matrix composition
2018
The aim of this study has been to investigate if wine matrix composition might influence the interaction between odorants and oral mucosa in the oral cavity during a “wine intake-like” situation. Aroma released after exposing the oral cavity of three individuals to different wines (n = 12) previously spiked with six target aromas was followed by an -in vivo intra-oral SPME approach. Results showed a significant effect of wine matrix composition on the intra-oral aroma release of certain odorants. Among the wine matrix parameters, phenolic compounds showed the largest impact. This effect was dependent on their chemical structure. Some phenolic acids (e.g. hippuric, caffeic) were associated t…
Development of a selective solid phase extraction method for nitro musk compounds in environmental waters using a molecularly imprinted sorbent
2013
A powerful analytical method for the determination of the family of the nitro musk compounds at trace level in environmental waters-river, sea, and water from a treatment plant-is presented. The method is based on the use of molecularly imprinted silica (MIS) as sorbent for solid phase extraction (SPE) used for the clean-up and the concentration step of the target analytes previous to their determination by gas chromatography-mass spectrometry. The optimized extraction procedure allowed extraction recoveries between 61% and 87% using the MIS. The comparison with a non-imprinted silica (NIS) sorbent, for which extraction recoveries between 8% and 26% were obtained, showed the high selectivit…
Identification of Bioactive Compounds in Polar and Nonpolar Extracts of Araujia sericifera
2017
Abstract Araujia sericifera is a native perennial, climbing laticiferous shrub from South America that is currently naturalized in many other countries. Previous data describe promising properties for A. sericifera, but no systematic study of its bioactive compounds and possible medicinal applications has been conducted to date. In the present study, aerial parts of A. sericifera (leaves, stems, and fruits) were explored by combining GC-MS and NMR spectroscopy analysis for both nonpolar (hexane) and polar (methanol) extracts. The hexanic extracts contained high amounts of pentacyclic triterpenes including two new metabolites, 3-tigloyl germanicol (18) and 3-tigloyl lupeol (19). The methanol…
Biogenic and biomass burning organic aerosol in a boreal forest at Hyytiälä, Finland, during HUMPPA-COPEC 2010
2013
Abstract. Submicron aerosol particles were collected during July and August 2010 in Hyytiälä, Finland, to determine the composition and sources of aerosol at that boreal forest site. Submicron particles were collected on Teflon filters and analyzed by Fourier transform infrared (FTIR) spectroscopy for organic functional groups (OFGs). Positive matrix factorization (PMF) was applied to aerosol mass spectrometry (AMS) measurements and FTIR spectra to identify summertime sources of submicron aerosol mass at the sampling site. The two largest sources of organic mass (OM) in particles identified at Hyytiälä were (1) biogenic aerosol from surrounding local forest and (2) biomass burning aerosol, …
Determination of alkylamines in atmospheric aerosol particles: a comparison of gas chromatography–mass spectrometry and ion chromatography approaches
2014
Abstract. In recent years low molecular weight alkylamines have been recognized to play an important role in particle formation and growth in the lower atmosphere. However, major uncertainties are associated with their atmospheric processes, sources and sinks, mostly due to the lack of ambient measurements and the difficulties in accurate quantification of alkylamines at trace level. In this study, we present the evaluation and optimization of two analytical approaches, i.e., gas chromatography–mass spectrometry (GC-MS) and ion chromatography (IC), for the determination of alkylamines in aerosol particles. Alkylamines were converted to carbamates through derivatization with isobutyl chlorof…
Analytical characterisation of the biodeterioration of diterpenoid labdanic varnishes used in pictorial techniques: Sandarac and Manila copal
2014
Abstract The deterioration produced by fungal and bacterial growth on the sandarac and Manila copal, diterpenoid varnishes traditionally used as art materials, was evaluated by gas chromatography–mass spectrometry (GC–MS), and pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). Test specimens, coated with a solidified thin layer of the studied varnishes, were inoculated and incubated with selected fungi and bacteria obtained from collections and oil paintings affected by biodeterioration, and analysed by the above mentioned techniques. Significant changes were detected, showing evidence of deterioration processes caused or favoured by some of the studied microorganisms.
Organic residues in lake and drinking water from the lagoa de Juturnaíba (região dos lagos - RJ, Brazil)
1997
Various analytical methods for the determination of organic residues in water were applied to samples from the Lagoa de Juturnaíba in the Região dos Lagos, east of Rio de Janeiro. The concentrations of more than 60 pesticides and of different aminopolycarboxylic acids were determined using GC/MS detection, and a GC/MS screening procedure was applied to detect additional compounds. None of the investigated pesticide residues could be detected in the lake water at detection limits of less than 100 ng/L. EDTA was detected at a concentration level of 2 mg/L in the lake and in drinking water prepared from this lake. Traces of biphenyl were identified by GC/MS in the lake water, the source of whi…