Application of Headspace Solid-Phase Microextraction for Determination of Chloro-Organic Compounds in Sewage Samples

Solid phase microextraction (SPME) has been optimized and applied to the determination of the volatile halogenated compounds (VHCs) and semi-volatile halogenated compounds (SVHCs). Three types of SPME fiber coated with different stationary phases (PDMS–100 μm, CAR/PDMS-75 μm, PDMS/DVB–65 μm) were used to examine their extraction efficiencies for the compounds tested. Experimental parameters such as the selection of SPME coatings, extraction time, and addition of salts were studied. The carboxen-polydimethylsiloxane (CAR/PDMS) fiber appears to be the most suitable for the determination of VHCs. Analytical parameters such as linearity, limit of detection, and precision were also evaluated. Application of ECD detector for the determination of VHCs and SVHCs allows their determination on the low concentration level, ranging from 0.005 to 0.8 μg/L−1. The HS-SPME-GC/ECD procedure gave good analytical precision expressed as relative standard deviation (RSD) (ranged from 5.08% to 8.07%) for a concentration level of 5 μg/L−1 and good linearity (r2 > 0.98) in a wide calibration range. The applied HS-SPME-GC/ECD method was found to be a quick and effective technique for the determination of microtrace amounts of volatile and semi-volatile halogenated compounds in samples containing high amounts of various organic compounds

Molecular characterisation of birch bark tar by headspace solid-phase microextraction gas chromatography–mass spectrometry: A new way for identifying archaeological glues

International audienceTo develop an analytical methodology, as non-destructive as possible, suitable for the identification of natural substances from archaeological origin, we studied the potentiality of solid-phase microextraction (SPME) for analysing birch bark tar, an adhesive commonly used during ancient times. First of all, birch bark tars were produced by a controlled heating of birch bark. The two kinds of samples obtained using different processes of fabrication, one at liquid state, the second one at solid state, were then analysed by headspace HS-SPME-GC–MS. Different conditions of sample treatment were tested (two different fibre coatings, various times and temperatures of extraction) in order to suggest optimal conditions for the analysis of birch bark tar. Both samples were shown to be rich in volatile organic components. Two main groups of constituents, namely phenolic compounds issued from lignin or tannin known to be present in bark and sesquiterpenoid hydrocarbons, secondary metabolites largely distributed in the plant kingdom, were detected for the first time in birch bark tar. HS-SPME-GC–MS appears thus to be a very efficient method for investigating the volatiles emitted by plant tars and could be further used for the study of birch bark tar samples issued from archaeological context

Chemical composition overview on two organic residues from the inner part of an archaeological bronze vessel from Cumae (Italy) by GC–MS and FTICR MS analyses.

A bronze vessel, containing solid black material, was found in a grave dated to the late eighth century BC and located in the Middle Tyrrhenian region. Two residue samples of this black material were subject to molecular characterization in order to assess first its composition and then the function of this precious object. Two different technique analyses, namely gas chromatography–mass spectrometry (GC–MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, in negative-ion mode (ESI(−) FTICR MS), were employed in that way. If GC–MS analysis is commonly used for the characterization of archaeological samples by identifying biomarkers related to organic material, FTICR MS was used to achieve a fast global molecular description with up to thousands of assignments. In addition, this technique enabled to hypothesize about the different materials involved in the black material composition. As a result, lipids, beeswax, conifer resin, and pitch from birch bark were supposed, which was thereafter confirmed by GC–MS. Consequently, FTICR MS can be regarded as an efficient tool for the fast profiling of the organic archaeological compounds