a combined gas chromatography–mass spectrometry (gc–ms) with headspace solid-phase microextraction (hs-spme) method has been employed for the analysis of the flavor volatiles of some iranian rice cultivars (domsiah, deylamani, hashemi, shirodi and tarom). the samples were grown in different cities of mazandaran province. the sampling procedure and chromatographic conditions were same for all sa...

Dermal exposures of methanol were administered in a clinical study designed to compare several biological indicators. Four subjects were exposed in five exposure sessions of varying length. In each session, a sequence of measurements of methanol concentrations in blood, breath, and headspace samples of air at exposed and unexposed skin were collected before and after dermal exposures. Skin head...

Headspace solid-phase microextraction (SPME) is a fast and simple sampling method for analysis of volatile compounds, but quantitation can be affected by sample matrix and sampling conditions. Sampling time and temperature are particularly important in controlling analyte response, and the effects vary for different compound classes and volatilities. Tests with model solutions containing a rang...

chiectasis and Cystic Fibrosis clinics. The gold standard for diagnosing P. aeruginosa infection was positive sputum cultures. 72 sputum samples were analysed. A sputum sample was kept in a glass vial with a cap containing septum. The septum was pierced with a solid phase microextraction (SPME) fibre allowing sampling of the headspace for 50 min at 378C before transferring the fibre into gas ch...

A solid-phase microextraction (SPME) method has been developed for the quantification of polychlorinated biphenyls (PCBs) in water samples. Parameters such as sampling time, volume of water, volume of headspace, temperature, addition of salts, and agitation of the sample were studied. Because the time for reaching equilibrium between phases takes several hours or days, depending on the experime...

Solid-phase microextraction (SPME) is a versatile new technique for collecting headspace volatiles prior to GC analysis. The commercial availability of uniform SPME fibers makes routine, practical quantitation of headspace concentrations possible, but straightforward information for relating GC peak areas from SPME analyses to headspace concentrations has not been available. The calibration fac...

Four of the major HS-GC analyses that are typically performed at breweries are described here (Table 1). The first, and most important, is monitoring for vicinal diketones (VDK) in the beer, which include 2,3-butanedione (diacetyl) and 2,3-pentanedione. VDK are considered extremely important since they are known to affect the taste of the beer. These components produce a butterlike flavor and a...

In this work, we illustrate the application of proton transfer reaction mass spectrometry (PTR-MS) in the field of food and drink safety. We present proof-of-principle measurements of four different drinks (water, tea, red wine and white wine) each spiked separately with four different date rape drugs (chloral hydrate, tricholorethanol, γ-butyrolactone and butanediol). At first, the ideal PTR-M...

Smokeless powder additives are usually detected from an extraction of post-blast residues or unburned powder particles followed by chromatographic analyses. This work presents the first comprehensive study of the detection of volatile and semi-volatile additives of smokeless powders using solid phase microextraction (SPME) as a sampling and pre-concentration technique. The goal of this study is...