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Abstract: Many complex natural or synthetic products are analysed either by the GC–MS (gas chromatography–mass spectrometry) or HPLC–DAD (high performance liquid chromatography–diode-array detector) technique, each of which produces a one-dimensional fingerprint for a given sample. This may be used for classification of different batches of a product. GC–MS and HPLC–DAD analyses of complex, similar substances represented by the three common types of the TCM (traditional Chinese medicine), Rhizoma Curcumae were analysed in the form of one- and two-dimensional matrices firstly with the use of PCA (Principal component analysis), which showed a reasonable separation of the samples for each technique. However, the separation patterns were rather different for each analytical method, and PCA of the combined data matrix showed improved discrimination of the three types of object; close associations between the GC–MS and HPLC–DAD variables were observed. LDA (linear discriminant analysis), BP-ANN (back propagation-artificial neural networks) and LS-SVM (least squares-support vector machine) chemometrics methods were then applied to classify the training and prediction sets. For one-dimensional matrices, all training models indicated that several samples would be misclassified; the same was observed for each prediction set. However, by comparison, in the analysis of the combined matrix, all models gave 100% classification with the training set, and the LS-SVM calibration also produced a 100% result for prediction, with the BP-ANN calibration closely behind. This has important implications for comparing complex substances such as the TCMs because clearly the one-dimensional data matrices alone produce inferior results for training and prediction as compared to the combined data matrix models. Thus, product samples may be misclassified with the use of the one-dimensional data because of insufficient information. [Copyright &y& Elsevier]

Abstract: Aspiration ion mobility spectrometry (IMS) has been used for the first time to screen 3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexaoxacyclononane explosive, the most commonly known as triacetone triperoxide (TATP). Gaseous TATP was generated from synthesized solid compound, sublimed and directed to a portable chemical detection system comprised of an aspiration-type IMS detector and six semiconductor sensors. Different unknown TATP gas phase concentrations were produced and corresponding IMS and semiconductor responses were measured. The experimental concentrations were determined by gas chromatography–mass spectrometry (GC–MS). The results evidenced that the monitored compound in the gas phase was TATP. In addition, the determined TATP concentrations and corresponding IMS intensities showed that the IMS response values were proportional to the measured TATP concentrations. [Copyright &y& Elsevier]

Abstract: Gas chromatography–mass spectrometry (GC–MS) combined with Chemometric resolution techniques were proposed as a method for the analysis of volatile components of Iranian damask rose oil. The essential oil of damask rose was extracted using hydrodistillation method and analyzed with GC–MS in optimized conditions. A total of 70 components were identified using similarity searches between mass spectra and MS database. This number was extended to 95 components with concentrations higher than 0.01% accounting for 94.75% of the total relative content using Chemometric techniques. For the first time in this work, an approach based upon subspace comparison is used for determination of the chemical rank of GC–MS data. The peak clusters were resolved using heuristic evolving latent projection (HELP) and multivariate curve resolution-alternating least square (MCR-ALS) by applying proper constraints, and the combination of both methods for some cases. It is concluded that a thorough analysis of the complex mixtures such as Iranian damask rose requires sophisticated GC–MS coupled with the Chemometric techniques. [Copyright &y& Elsevier]

Abstract: This article presents a method employing stir bar sorptive extraction (SBSE) with in situ derivatization, in combination with either thermal or liquid desorption on-line coupled to gas chromatography–mass spectrometry for the analysis of fluoxetine in plasma samples. Ethyl chloroformate was employed as derivatizing agent producing symmetrical peaks. Parameters such as solvent polarity, time for analyte desorption, and extraction time, were evaluated. During the validation process, the developed method presented specificity, linearity (R 2 >0.99), precision (R.S.D.<15%), and limits of quantification (LOQ) of 30 and 1.37pgmL−1, when liquid and thermal desorption were employed, respectively. This simple and highly sensitive method showed to be adequate for the measurement of fluoxetine in typical and trace concentration levels. [Copyright &y& Elsevier]

Abstract: Lavandin, a sterile hybrid of Lavandula angustifolia P. Mill.× Lavandula latifolia (L.f.) Medikus (Lamiaceae) is a plant widely cultivated for essential oil production in the South of France. Chemometric treatment by mid-infrared (MID-IR) spectroscopy data was assessed for the differentiation of Grosso Lavandin Essential Oils of Controlled Area (GLEOCA) and results were compared to those obtained by gas chromatography for MID-IR short time technique validation. The quantification of the main 13 hydrocarbons and oxygenated compounds generally controlled by industrial perfumers in GLEOCA samples (n =83) of three geographic origins: “Simiane”, “Puimoisson” (with two producers) and “Richerenches” and their classification were successfully obtained by partial least square discriminant analysis (PLS-DA) by comparison with gas chromatography. The best prediction results were obtained using first derivate spectral data in the 1800–700cm−1 range. The spectroscopic interpretation of regression vectors showed that each geographic origin was correlated to components of GLEOCA. Chemometric MID-IR spectra treatments allowed us to obtain similar results than those obtained by time consuming analytical techniques such as GC and therefore constitute a robust and help fast method for authentication of GLEOCA and should be extended to other essential oils for authentication of geographic origin. [Copyright &y& Elsevier]

Abstract: A multi-method approach has been developed for the characterisation of the proteinaceous binding media, drying oils and pigments present in samples from the panel paintings of the Church of the Assumption in Cephalonia (Ionian Islands, Greece). The analytical protocol involved the use of scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDX), Raman spectroscopy and gas chromatography. The identification of the pigments was achieved by SEM/EDX and Raman spectroscopy. The latter technique was also used for the detection of the binding media, while their characterisation was achieved by gas chromatographic analysis of ethyl chloroformate derivatives. The aim of this multi-method protocol was to obtain as much information as possible from the panel paintings of the Church of the Assumption, through non-destructive methods, before proceeding to gas chromatography. Little scientific information is available for the understanding of the construction technique and the materials used by the post-Byzantine artists and whatever is available comes mainly from artists’ manuals. One of the aims of this paper is to provide a scientific background to the technology of the Ionian post-Byzantine icons. [Copyright &y& Elsevier]

Abstract: The resinous materials from the interior surfaces of two Roman and one Iberian amphora were studied with Fourier transform infrared (FTIR) spectroscopy. The results were then compared with those obtained by synchrotron radiation-FTIR, scanning electron microscopy (SEM), and gas chromatography–mass spectrometry (GC–MS). The FTIR spectra obtained by the technique of KBr micropellets, prepared directly with the materials scraped from the amphora without any further sample preparation, provided enough information to establish their diterpenoic nature, and even to differentiate between the two main materials employed for waterproofing purposes, pitch and wood tar. Methyl dehydroabietic acid (DHAM) is the main chemical marker that allows a distinction to be made between these two materials. Pitch and wood tar were prepared in the laboratory heating pine resin and resinous pine wood, respectively. These resinous waterproofing materials were compared with the coatings extracted from the amphorae. The samples whose direct FTIR spectra showed a signal at ∼1740cm−1, attributed to a carbonyl group of methyl ester, presented as well a peak of DHAM in the GC–MS chromatogram of the neutral fraction of their extract. Samples without this signal in their spectra did not present DHAM in their chromatogram. This work studies, for the first time, waterproofing of an amphora attributed to the Iberian culture. [Copyright &y& Elsevier]

Abstract: The aim of this study was to evaluate the performance characteristics of the recently developed super elastic solid-phase microextraction (SPME) fibers. The fiber needle, plunger and fiber core are manufactured with a special type of flexible alloy that exhibits excellent shape memory and tensile strength. This material makes the assemblies more robust, permitting several hundreds of analyses in a sequence, which is one of the ways to improve the robustness and sample throughput of automated SPME methods. The design and size of the needle utilized in the new fiber assemblies is discussed here, as well as the use of a septum-free injector replacement and a low-volume direct injection glass liner placed in the GC inlet. Deionized water and pump oil samples spiked with target volatile compounds (McReynold''s probes and toluene) were used for the purposes of the presented study. A fully automated SPME sample preparation technique was combined with the GC–TOFMS system for the chromatographic separation and identification/quantification of the target analytes. [Copyright &y& Elsevier]

Abstract: Wax sculptures contain several materials from both organic and inorganic nature. These works of art are particularly fragile. Determining their chemical composition is thus of prime importance for their preservation. The identification of the recipes of waxy pastes used through time also provides valuable information in the field of art history. The aim of the present research was to develop a convenient analytical strategy, as non-invasive as possible, that allows to identify the wide range of materials involved in wax sculptures. A multi-step analytical methodology, based on the use of complementary techniques, either non- or micro-destructive, was elaborated. X-ray fluorescence and micro-Raman spectroscopy were used in a non-invasive way to identify inorganic pigments, opacifiers and extenders. The combination of structural and separative techniques, namely infrared spectroscopy, direct inlet electron ionisation mass spectrometry and high temperature gas chromatography, was shown to be appropriate for unravelling the precise composition of the organic substances. A micro-chemical test was also performed for the detection of starch. From this study it has been possible to elucidate the composition of the waxy pastes used by three different sculptors at the end of the 19th century. Complex and elaborated recipes, in which a large range of natural substances were combined, were highlighted. [Copyright &y& Elsevier]

Abstract: Linear alkylbenzenes (LABs) are discharged into the environment as sub-products of linear alkylbenzenesulfonate (LAS) detergent. Their association with LAS is attributed to the incomplete sulfonation of the LABs in detergent manufacturing resulting in products having LAB. Recently there has been widespread interest in their use as markers of sewage effluent in the aquatic environment. Although LABs may be potentially useful in assessing the distribution and degradation of domestic wastewater, studies about it are still limited probably due to the analytical difficulties. In this article, a new analytical method for the determination of LABs in detergents using gas chromatography coupled to mass spectrometry (GC–MS) in combination with solid phase microextraction (SPME) is proposed. This alternative sample preparation technology presents several advantages, since it is solvent free, fast, uses the whole sample for analysis, requires only small amounts of sample and the fibers for the extraction procedure are reusable. A factorial experimental design was utilized to obtain the optimum values for the main operational parameters in the analysis of LABs in detergents using direct SPME in the pre-concentration step. [Copyright &y& Elsevier]

Abstract: Two-phase O-ethoxycarbonylation was performed to alkylphenols in acidic solution with ethyl chloroformate present in dichloromethane phase fortified with triethylamine with subsequent N-ethoxycarbonylation of amines after adjusting to alkaline pH. The resulting ethoxycarbonyl derivatives were subjected to pentafluoropropionylation, clean-up and concentration for analysis by gas chromatography and gas chromatography–mass spectrometry. The present method was linear (r ≥0.9959) in the range of 0.5–10.0μgml−l with good precision (≤9.5%) and accuracy (−8.9 to 9.5%) for 20 phenols and 27 amines examined, allowing simultaneous screening for a total of one alkylphenol and four amines from wine and beer. [Copyright &y& Elsevier]

Abstract: In the analysis of an environmental disaster caused by spillage of crude oil, limitation of the possible sources to a few geographical origins can help in the identification of the polluting vessel from a group of potential candidates. In this paper we show that Kohonen self-organizing maps (or Kohonen neural networks) can classify samples of crude oils on the basis of gas chromatography–mass spectrometry (GC–MS) descriptors, in terms of geographical origin, with a high degree of accuracy. Two data sets were investigated – one from Instituto Hidrográfico (Lisbon, Portugal) with 188 samples from 20 geographical origins, and another from EUROCRUDE® with 374 samples. After training the Kohonen self-organizing maps with a training set, predictions were obtained for an independent test set. Correct predictions were obtained for 70% and 60% of the test sets for the two studies, respectively. Ensembles of networks were highly interesting for the calculation of a prediction score, which can be used as a measure of the reliability of the prediction. For the samples with high prediction scores, the percentage of correct predictions jumped to 94–96%. The ability of the maps to identify a given origin is very much dependent on the availability of samples from that class in the training set. Equally good predictions were obtained for a small test set of weathered samples. This investigation adds value to the GC–MS descriptors already in use for practical analytical work, suggesting new ways to ferret out useful knowledge from them. [Copyright &y& Elsevier]

Abstract: In the work, for the first time, two solvent-free sample preparation techniques of microwave distillation (MD) and solid-phase microextraction (SPME) were combined, and developed for determination of essential oil compounds in traditional Chinese medicine (TCM). Using the proposed method, isolation, extraction and concentration of TCM essential oil compounds can be carried out in a single step. To demonstrate its feasibility, MD-SPME was compared with a conventional technique, steam distillation (SD), for gas chromatography-mass spectrometry (GC-MS) analysis of essential oil compounds in a TCM, Artemisia Selengensis Turcz. Forty-nine compounds in the TCM were separated and identified by the present method, while only 26 compounds were detected by SD method. Relative standard deviation (R.S.D.) values less than 9% show that the present method has good precision. The SD method required long time (6h) to isolate of the essential oil, and large amount of organic solvent for further extraction, while MD–SPME needed little time (only 3min) to prepare sample, and no organic solvent. These results show that MD–SPME–GC-MS is a simple, rapid and solvent-free method for determination of TCM essential oil. [Copyright &y& Elsevier]

Abstract: This study summarizes the results obtained from the doping control analysis during the period of the XXVIII summer Olympic Games (30 July–29 August 2004). The analysis of all doping control samples was performed at the Doping Control Laboratory (DCL)—the World Anti-Doping Agency (WADA) Accredited Laboratory of Athens. Three thousand six hundred and seventeen tests were conducted in total throughout the games. In 23 specimens the presence of a prohibited substance was confirmed. Sixteen of those were related to anabolic agents. The screened results were confirmed with various mass spectrometry analytical techniques, such as gas chromatography/high resolution mass spectrometry (GC/HRMS), gas chromatography/mass spectrometry (GC/MS), gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) and liquid chromatography/mass spectrometry (ion trap) (LC/MS). The results of the first time applied screening and confirmatory procedures for the detection of recombinant human growth hormone in serum were also presented. Besides, 107 therapeutic use exemptions (TUE) were verified for glucocorticosteroid and beta2-agonist use. [Copyright &y& Elsevier]

Abstract: A procedure for the determination of three chloroanisoles (2,4,6-trichloro, 2,3,4,6-tetrachloro and pentachloroanisol), as well as their precursor chlorophenols (2,4,6-trichloro, 2,3,4,6-tetrachloro and pentachlorophenol), involved in the presence of cork taint in red wine has been developed. Samples, up to 1l, were concentrated using a 200mg Oasis HLB solid-phase extraction (SPE) cartridge. Chlorophenols were quantitatively eluted from this sorbent with 3ml of methanol. Chloroanisoles were mainly recovered in a second fraction of n-hexane (2ml). Both fractions were combined and mixed with an aqueous solution of sodium bicarbonate and 50μl of acetic anhydride. Chlorophenols were acetylated in the aqueous-methanolic phase and extracted to n-hexane. Chloroanisoles remained unaffected in the n-hexane layer. Both groups of compounds were determined by gas chromatography–tandem mass spectrometry in the same chromatographic analysis. Using a temperature programmable vaporization injector detection limits from 0.2 to 2.4ngl−1, below their sensorial threshold level in red wine, were obtained for all compounds. Average recoveries higher than 80% and acceptable precision were achieved using red wine samples spiked with the analytes at different concentration levels. [Copyright &y& Elsevier]

Abstract: In the study, we developed a simple, rapid, sensitive, and inexpensive method for determination of the disease biomarkers of acetone, hexanal and heptanal in human blood. For the first time, derivatization of carbonyls with O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine (PFBHA) was combined with headspace single-drop microextractin (HS-SDME) and gas chromatography-mass spectrometry (GC–MS) and applied to the analysis of acetone, hexanal, and heptanal in human blood. At first, acetone, hexanal and heptanal in blood were derivatized with PFBHA and formed oximes in several seconds. Sequentially, the oximes were headspace extracted and concentrated by a microdrop solvent. Finally, the extracted oximes were analyzed by GC–MS. HS-SDME conditions and method validations were studied. Due to needing of only 2μl organic solvent, short extraction time of 8min, and simple operation, derivatization-HS-SDME was shown to be a rapid, simple, and inexpensive technique for analysis of acetone, hexanal, and heptanal in human blood. Moreover, it had low detection limit values from 0.24 to 0.62nM, and good reproducibility (R.S.D. less than 12%). [Copyright &y& Elsevier]

Abstract: Stir bar sorptive extraction (SBSE) using a 10mm-long stir bar coated with 24μl of polydimethylsiloxane (PDMS) in combination with the thermal desorption technique and gas chromatography–mass spectrometry was used for determining hydroxy polycyclic aromatic hydrocarbons (OH-PAHs), particularly mono and diOH-PAHs having two- to four-ring structures, in water samples. To improve the recovery for OH-PAHs, in situ derivatization with acetic anhydride was applied prior to SBSE. The optimal conditions for a 10ml water sample were attained with the addition of 100mg of sodium hydrogen carbonate, followed by the addition of 20μl of acetic anhydride and extraction for 360min. In the selected ion monitoring (SIM) mode, the limits of detection were found to range from 0.27ngl-1 for 2-hydroxynaphthalene (as 2-hydroxynaphthalene acetate) to 25ngl-1 for 1,4-dihydroxynaphthalene (as 1,4-naphthoquinone) (S/N=3). The low total recovery (<50%) of the entire procedure was mainly due to the low extraction efficiency of acetyl derivatives from water to PDMS, while the in situ derivatization step achieved more than 88% efficiency. Nine OH-PAHs, such as 1,4-naphthoquinone, 2-hydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 9-hydroxyphenanthrene, were detected in environmental samples under the optimal conditions. The detection of OH-PAHs in environmental water samples has not been reported so far. [Copyright &y& Elsevier]

Abstract: Various sampling techniques including flash evaporation (FE), headspace solid-phase microextraction (HS-SPME) and steam distillation (SD) were compared for the gas chromatography–mass spectrometry of volatile constituents present in Houttuynia cordata Thunb (HCT). 2-Undecanone (22.21%) and houttuynum (7.23%) were predominant components of HCT samples obtained by HS-SPME whereas those levels were 3.95 and 3.60% in the same samples by FE and 25.93 and 6.60% in those by SD, respectively. SPME with polydimethylsiloxane (PDMS) fibre was more selective and particularly efficient for the isolation of biologically active compounds and afforded a higher yield of total compounds than FE and SD. A total of 60 compounds were detected in SPME extracts. While in FE and SD extracts, the detected compounds were 41 and 51, respectively. The total amount of compounds isolated by SPME was much larger than that isolated by FE or SD. Some minor constituents were isolated by SPME, but not by SD and FE. This carries great significance because of the importance of the oil volatiles to clinical therapy. HS-SPME is a powerful tool for determining the volatile constitutes present in the TCMs. [Copyright &y& Elsevier]

The powerful capabilities of the stir bar sorptive extraction followed liquid desorption in combination with large volume injection and capillary gas chromatography coupled to mass spectrometry, were successfully applied to screen more than 60 endocrine disrupters chemicals, including herbicides, organochlorine and organophosphorous pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, biocides, phthalates and alkylphenols in water samples at the ultra-trace level.During method development, it has been established that stir bars coated with 47 μL of polydimethylsiloxane, a standard equilibrium time of 60 min (750 rpm) at room temperature (20 °C) and acetonitrile as back extraction solvent, promote good performance to monitor endocrine disrupters chemicals in water samples. Assays on 30 mL laboratory-spiked water samples having a minimum of 5% of methanol, allowed high sensitivity and remarkable reproducibility (<18.4%) for screening endocrine disrupters chemicals at the 0.10 μg/L level. The data obtained from the recovery yields shows that stir bar sorptive extraction followed liquid desorption could be described by the octanol–water partition coefficients (KO/W), in which some of the deviations correspond to particular compounds where equilibrium conditions were not achieved. From calibration studies, excellent linear dynamic ranges were obtained for almost all endocrine disrupters chemicals from water samples at the ultra-trace level (0.025–0.400 μg/L).The present methodology is a cost-effective alternative for routine quality control analysis, showing to be easy, very sensitive and not much volume of water sample is required to screening endocrine disrupters chemicals in compliance with European Union directives on water quality. [Copyright &y& Elsevier]

Solid-phase microextraction (SPME) coupled to ultrasonic extraction was evaluated for extracting trace amounts of two agrochemical fungicides, vinclozolin and dicloran, in soil samples. Extraction was performed following two experimental approaches prior to the submission of the aqueous extracts to SPME–GC analysis. In the first approach, extraction involved sample homogenization with a water solution containing 5% (v/v) acetone and centrifugation prior to fiber extraction. In the second approach, the extraction of the fungicides from the soil samples was conducted using acetone as organic solvent which was then diluted with water to give a 5% (v/v) content. The pesticides were isolated with fused silica fiber coating with 85 μm polyacrylate. Parameters that affect both the extraction of the fungicides by the soil samples and the trapping of the analytes by the fiber were investigated and their impact on the SPME–GC–MS was studied. The procedures with respect to repeatability and limits of detection were evaluated by soil spiked with both analytes. Repeatability was between 5.6 and 14.2% and the limits of detection were 2–13 ng g-1. The efficiency of acetone/SPME was generally better than that for water/SPME procedure showing good linearity (R2>0.99) with coefficient variations below 9%, recoveries higher than 91% and limits of detection between 2 and 3 ng g-1. Finally, the recoveries obtained with acetone/SPME procedure were compared with the conventional liquid–liquid extraction using real soil samples. The acetone/SPME method was shown to be an inexpensive, fast and simple preparation method for the determination of target analytes at low nanogram per gram levels in soils. [Copyright &y& Elsevier]