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HS-SPME–GC–MS in combination with PCA was employed to discriminate different arabica/robusta blends having different geographical origins. HS-SPME confirmed to be an effective and reproducible sampling technique for routine characterization of coffees. In addition, the chemometric approach permitted to find parameters suitable for the differentiation of the different blends and the determination of...
The identification and quantification of semi-volatile contaminants dissolved in water is currently done in laboratory after a sampling step. This procedure is not satisfactory first because risks of samples contamination and analytes losses remain, in particular when these are present in ultra-trace concentrations, and secondly because procedures are time-consuming. The coupling of the stir bar sorptive...
We have developed a new method for the determination of the widely used herbicide 2,6-dichlorobenzonitrile (dichlobenil) and its major metabolites 2,6-dichlorobenzamide (BAM) and 2,6-dichlorobenzoic acid (2,6-DCBA) in groundwater samples. The procedure is based on solid phase extraction (SPE) combined with a derivatization procedure before GC–MS analysis in order to quantify analytes simultaneously...
A technique for the analysis of organophosphorus pesticides (ethoprop, diazinon, disulfoton, fenthion) in aqueous sample using liquid-phase microextraction (LPME), coupled with gas chromatography–mass spectrometry (GC–MS) was developed. A small section of a hollow fiber inserted into the needle of GC syringe and filled with the 3.5μl of organic solvent was used to extract pesticides from a 20ml aqueous...
An analytical method for the determination of polybrominated diphenyl ethers (PBDEs) in soil was developed. Soil samples were placed in small glass columns and PBDEs extracted from soil, with a low volume of ethyl acetate (5mL, 2× 15min), assisted by sonication. PBDEs were determined by gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC–MS–SIM)...
A gas chromatography–mass spectrometry (GC–MS) method has been proposed for the simultaneous determination of aliphatic and aromatic amines in indoor and outdoor air samples. The method includes pre-concentration of the compounds by percolating the air samples through the acidic solution, ion-pair extraction with bis-2-ethylhexylphosphate (BEHPA), derivatisation of compounds with isobutyl chloroformate...
The aim of present work was to optimize the experimental parameters in single drop microextraction under solution immersion (SDME) and headspace (HS-SDME) extraction modes for the determination of periodate using guaifenesine [3-(2′-methoxyphenoxy)-1,2-propane diol] and norephedrine (phenylpropanolamine) as new and alternative reagents for the Malaprade reaction. The reactions were complete within...
A method is reported for the determination of acaricides (amitraz, bromopropylate, coumaphos and fluvalinate) from honey by gas chromatography mass spectrometry after a new fast solid phase micro-extraction, SPME, procedure. Six different fibers were assessed for micro-extraction purpose studying the following variables: (i) SPME coating, (ii) extraction temperature, (iii) extraction time, (iv) desorption...
This study evaluated the derivatization procedures for detecting the three most commonly monosaccharide anhydrides (MAs) (levoglucosan, mannosan and galactosan) in atmospheric aerosols using gas chromatography–mass spectrometry (GC–MS). Various silylating agents, mainly trimethylsilylating agents (TMS), were compared and the effects of various contents of trimethylchlorosilane (TMCS, as a stimulator)...
Ethyl parathion and toluene 2,4-diisocyanate (2,4-TDI) vapors were generated using a vapor generation system that was designed for the evaporation of liquid samples at known flow rates. The vapor generation of parathion and 2,4-TDI posed a challenge because of their low volatility and tendency to absorb into surfaces of the vapor generation system. Experimental concentration of parathion was determined...
This paper describes the validation of a method for the determination of 24 priority substances from the European Framework Directive in estuarine and sea water using the new extraction technique known as stir bar sorptive extraction (SBSE), followed by thermal desorption using capillary gas chromatography–mass spectrometry. We studied linearity, detection and quantitation limits and accuracy (which...
Analytical methodologies employed in biodesulfurization processes have been reviewed; attention is primarily focused on the use of analytical techniques in the identification of degradation products and on the monitoring of degradation processes in which microbial sulphur-specific transformations take place. This is the first review of analytical techniques applied to biodesulfurization processes...
A new approach was explored to purify proteins in a multi-step procedure for the characterisation of proteinaceous materials (casein, animal glue, and egg) in artwork samples by gas chromatography–mass spectrometry. High concentrations of inorganic salts, such as azurite, have been found to impair the determination of protein via amino acid analysis. The effect of varying concentrations of copper-based...
The last two decades have witnessed growing scientific and public concerns over endocrine disrupting compounds (EDCs) that have the potential to alter the normal structure or functions of the endocrine system in wildlife and humans. In this study, the phenolic EDCs such as alkylphenol, chlorinated phenol and bisphenol A were considered. They are commonly found in wastewater discharges and in sewage...
Headspace single drop microextraction coupled to gas chromatography–mass spectrometry yielded a simple, fast and virtually solventless analytical protocol used for the headspace analysis of aqueous samples contaminated with methylcyclopentadienyl-manganese tricarbonyl (MMT). Initially, several experimental parameters were controlled and optimized and the optimum conditions found were 2.5μl octane...
Within the framework of an Italian research project aimed at studying organic residues found in archaeological objects from the Roman period, the chemical composition of the contents of several glass vessels recovered from archaeological sites from the Vesuvian area (Naples, Italy) was investigated.In particular, this paper deals with the study of an organic material found in a glass bottle from the...
A new approach for the extraction of nine kinds of organochlorine pesticides (OCPs) from vegetable samples coupling single-drop microextraction with gas chromatography–mass spectrometry was presented. Experimental parameters, such as organic solvent, exposure time, agitation and organic drop volume were controlled and optimized. An effective extraction was achieved by suspending a 1.00μL mixed drop...
The use of two automated sample preparation techniques, solid-phase microextraction (SPME) and purge and trap (P&T) systems are critically compared for the GC–MS determination of eight volatile organic compounds (VOCs), including trihalomethanes (THMs), in drinking water samples. Compounds chosen for the comparison are regulated by Spanish and European official guidelines for drinking waters....
Alternative moving window factor analysis (AMWFA) has shown the powerfulness for comprehensive comparison and individual identification of chemical components among different but related mixture systems. However, quantification of these components can only be attained after extraction of all spectra of pure components in samples with least square technique. In this study, a novel two-step iterative...
A method based on matrix solid-phase dispersion (MSPD) has been developed for the determination of 16 organochlorine pesticides (OCs) in sludge from municipal sewage plants. Samples of lyophilized sludge were blended with alumina, placed in small columns and OCs extracted with dichloromethane assisted by sonication. Purification of the extracts was accomplished by solid-phase extraction on C 18...
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