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Shuaihua Zhang, Qian Yang, Xiumin Yang, Wenchang Wang, Zhi Li, Lihong Zhang, Chun Wang, Zhi Wang
A high-surface-area nanoporous carbon (NPC) has been successfully synthesized by using the metal-organic framework ZIF-90 as both the template and precursor together with furfuryl alcohol as a secondary carbon source. The prepared ZIF-90 templated NPC (ZIF-90-NPC) was then coated onto a stainless steel wire by a simple physical adhesion approach to prepare solid-phase microextraction (SPME) fiber. By coupling the ZIF-90-NPC coated fiber-based SPME with gas chromatography-microelectron capture detection (GC-μECD), the developed method gave a large enhancement factor (984-2869), low limit of detection (0...
May 1, 2017: Talanta
A Gotor-Vila, N Teixidó, A Di Francesco, J Usall, L Ugolini, R Torres, M Mari
The present work focuses on the antifungal effect of volatile organic compounds (VOCs) produced by Bacillus amyloliquefaciens CPA-8 against Monilinia laxa, M. fructicola and Botrytis cinera, three postharvest fruit pathogens of sweet cherry fruit. VOCs were evaluated with a double petri dish assay against mycelial and colony growth of target pathogens. For this purpose, CPA-8 was grown on different media and cultured for 24 and 48 h at 30 °C before assays. Data showed that mycelial growth inhibition was higher when CPA-8 was grown on Tryptone Soya Agar (TSA) while no differences were generally observed when CPA-8 was cultured for either, 24 and 48 h...
June 2017: Food Microbiology
Heidi Birch, Henrik R Andersen, Mike Comber, Philipp Mayer
During simulation-type biodegradation tests, volatile chemicals will continuously partition between water phase and headspace. This study addressed how (1) this partitioning affects test results and (2) can be accounted for by combining equilibrium partition and dynamic biodegradation models. An aqueous mixture of 9 (semi)volatile chemicals was first generated using passive dosing and then diluted with environmental surface water producing concentrations in the ng/L to μg/L range. After incubation for 2 h to 4 weeks, automated Headspace Solid Phase Microextraction (HS-SPME) was applied directly on the test systems to measure substrate depletion by biodegradation relatively to abiotic controls...
February 3, 2017: Chemosphere
Cláudia M Dias, Helvécio C Menezes, Zenilda L Cardeal
Acrolein is a pollutant released daily to the indoor environment from different sources. The present study reports the development of a simple and sensitive cold fiber solid phase microextraction sampling method for the determination of acrolein in exhaled air and indoor air by gas chromatography mass spectrometry. O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine was used as derivatizing agent supported on a 65-μm polydimethylsiloxane-divinylbenzene SPME fiber. An acrolein permeation tube at 326.25 ng min(-1) rate was used to generate gaseous standards...
February 15, 2017: Analytical and Bioanalytical Chemistry
Yuanyuan Jin, Zhongyue Li, Lei Yang, Jun Xu, Le Zhao, Zhonghao Li, Jiajia Niu
A novel solid-phase microextraction (SPME) fiber was fabricated by a porous aromatic framework 48 (PAF-48)/gel hybrid material through a sol-gel process. PAF-48 is a porous organic framework (POF) material that was polymerized from 1,3,5-triphenylbenzene. The uniform pore structure, high surface area, continuous conjugate network, and hydrophobicity make PAF-48 expected to have special abilities to absorb and extract styrene as well as some other harmful volatile aromatic compounds (VACs). The PAF-48/gel-coated fiber was explored for the extraction of styrene and six VACs (benzene, toluene, ethylbenzene, and xylenes) from aqueous food simulants followed by gas chromatography (GC) separation...
January 17, 2017: Analytical Chemistry
Federico Magagna, Chiara Cordero, Cecilia Cagliero, Erica Liberto, Patrizia Rubiolo, Barbara Sgorbini, Carlo Bicchi
Tea prepared by infusion of dried leaves of Camellia sinensis (L.) Kuntze, is the second world's most popular beverage, after water. Its consumption is associated with its chemical composition: it influences its sensory and nutritional quality addressing consumer preferences, and potential health benefits. This study aims to obtain an informative chemical signature of the volatile fraction of black tea samples from Ceylon by applying the principles of sensomics. In particular, several high concentration capacity (HCC) sample preparation techniques were tested in combination with GC×GC-MS to investigate chemical signatures of black tea volatiles...
June 15, 2017: Food Chemistry
Hamed Piri-Moghadam, Sofia Lendor, Janusz Pawliszyn
The aim of the current study is to develop a sensitive solid-phase microextraction (SPME) device for direct and rapid analysis of untreated complex matrixes (i.e., single drop of the samples, V ≤ 2 μL). A thin layer of a biocompatible nanostructured polypyrrole (PPy) was electrochemically deposited inside a medical grade spinal needle, minimizing the matrix effect. Microsampling was facilitated by loading the sample inside the in-tube SPME device (withdraw of sample via plunger), where extraction was performed under static conditions...
December 20, 2016: Analytical Chemistry
Erica A Souza-Silva, Emanuela Gionfriddo, Md Nazmul Alam, Janusz Pawliszyn
The currently presented research investigated the performance of matrix compatible PDMS-overcoated fibers (PDMS-DVB/PDMS) as compared to unmodified PDMS/DVB coatings using aqueous samples, and employing a wide range of analyte polarities, molecular weights, and functionalities. In the first part of the work, a kinetic approach was taken to investigate the effect of the PDMS outer layer on the uptake rate of analytes during the mass transfer process. In short, the results can be simplified into two models: (1) the rate-limiting step is the diffusion through the coating, and (2) the rate-limiting step is the diffusion through the aqueous diffusional boundary layer...
February 7, 2017: Analytical Chemistry
Germán Augusto Gómez-Ríos, Chang Liu, Marcos Tascon, Nathaly Reyes-Garcés, Don W Arnold, Thomas R Covey, Janusz Pawliszyn
In recent years, the direct coupling of solid phase microextraction (SPME) and mass spectrometry (MS) has shown its great potential to improve limits of quantitation, accelerate analysis throughput, and diminish potential matrix effects when compared to direct injection to MS. In this study, we introduce the open port probe (OPP) as a robust interface to couple biocompatible SPME (Bio-SPME) fibers to MS systems for direct electrospray ionization. The presented design consisted of minimal alterations to the front-end of the instrument and provided better sensitivity, simplicity, speed, wider compound coverage, and high-throughput in comparison to the LC-MS based approach...
February 13, 2017: Analytical Chemistry
Praetinee Pattamayutanon, Sergio Angeli, Prodpran Thakeow, John Abraham, Terd Disayathanoowat, Panuwan Chantawannakul
The volatile organic compounds (VOCs) of four monofloral and one multifloral of Thai honeys produced by Apis cerana, Apis dorsata and Apis mellifera were analyzed by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography and mass spectrometry (GC-MS). The floral sources were longan, sunflower, coffee, wild flowers (wild) and lychee. Honey originating from longan had more VOCs than all other floral sources. Sunflower honey had the least numbers of VOCs. cis-Linalool oxide, trans-linalool oxide, ho-trienol, and furan-2,5-dicarbaldehyde were present in all the honeys studied, independent of their floral origin...
2017: PloS One
Lucile Allamy, Philippe Darriet, Alexandre Pons
The main goal of this research was to identify key aroma compounds involved in the dried fruits (prune and dry fig) aroma of musts. An odoriferous zone (OZ) was detected by gas chromatography coupled with olfactometry (GC-O) and identified as (Z)-1,5-octadien-3-one (geranium). A quantitation method by SPME-GC-MS (CI, MeOH) was developed and validated for assaying this very fragrant ketone in musts for the first time (LOD: 0.15 ng/L; LOQ: 0.5 ng/L). Concentrations of (Z)-1,5-octadien-3-one in musts marked by dried fruits flavors reached 90 ng/L, thus exceeding its detection threshold (Dth 9 ng/L)...
February 11, 2017: Journal of Agricultural and Food Chemistry
Wenlin Huang, Benjamin C Blount, Clifford H Watson, Christina Watson, David M Chambers
To accurately measure menthol levels in human urine, we developed a method using gas chromatography/electron ionization mass spectrometry with menthol-d4 stable isotope internal standardization. We used solid phase microextraction (SPME) headspace sampling for collection, preconcentration and automation. Conjugated forms of menthol were released using β-glucuronidase/sulfatase to allow for measuring total menthol. Additionally, we processed the specimens without using β-glucuronidase/sulfatase to quantify the levels of unconjugated (free) menthol in urine...
December 13, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Martina Fortini, Marzia Migliorini, Chiara Cherubini, Lorenzo Cecchi, Luca Calamai
The commercial value of virgin olive oils (VOOs) strongly depends on their classification, also based on the aroma of the oils, usually evaluated by a panel test. Nowadays, a reliable analytical method is still needed to evaluate the volatile organic compounds (VOCs) and support the standard panel test method. To date, the use of HS-SPME sampling coupled to GC-MS is generally accepted for the analysis of VOCs in VOOs. However, VOO is a challenging matrix due to the simultaneous presence of: i) compounds at ppm and ppb concentrations; ii) molecules belonging to different chemical classes and iii) analytes with a wide range of molecular mass...
April 1, 2017: Talanta
Xialin Luo, Gongke Li, Yufei Hu
In this work, a novel NH2-MIL-53(Al) incorporated poly(styrene-divinylbenzene-methacrylic acid) (poly(St-DVB-MAA)) monolith was prepared via chemical fabrication. Moreover, it has been efficiently applied to the in-tube solid-phase microextraction (SPME) for online coupling with high-performance liquid chromatography (HPLC) to the direct determination of five estrogens in human urine samples. The NH2-MIL-53(Al)-polymer monolith was suitable for in-tube SPME owing to its good permeability, high extraction efficiency, chemical stability, good reproducibility and long lifetime...
April 1, 2017: Talanta
Jie Huang, Changrong Ou, Fangying Lv, Yuting Cao, Haiqing Tang, You Zhou, Ning Gan
Some harmful aliphatic diamines, e.g., putrescine (Put) and cadaverine (Cad), play important roles in food safety evaluation. In this study, we proposed on-fiber derivatization solid-phase microextraction analysis of non-volatile aliphatic diamines in fish using zeolitic imidazolate framework 8 (ZIF-8) as a solid-phase microextraction (SPME) coating. It was employed to encapsulate isobutyl chloroformate (IBCF, 40°C, 15min) for aqueous extraction of Put and Cad. After that, the derivatized aliphatic amines were thermally desorbed in the GC injection port and analyzed by GC-MS...
April 1, 2017: Talanta
Miao Pei, Zirui Zhang, Xiaojia Huang, Yuanfei Wu
A multiple monolithic fiber solid-phase microextraction (MMF-SPME) utilizing polymeric ionic liquid-based adsorbent was prepared. The adsorbent was obtained by in situ copolymerization of an ionic liquid, 1-trimethyl-(4-vinylbenzyl) aminium chloride and dual cross-linkers (divinylbenzene and ethylenedimethacrylate). The effect of preparation conditions including the content of ionic liquid and porogen in the polymerization mixture on extraction performance was studied in detail. Infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry were used to inspect the physicochemical properties of the new adsorbent...
April 1, 2017: Talanta
Małgorzata Anna Majcher, Kamila Myszka, Anna Grygier, Anna Gracka, Henryk H Jelen
Application of gas chromatography olfactometry (GC-O) carried out on the volatile fraction isolated by solvent assisted flavor evaporation (SAFE) and solid phase microextraction (SPME) from Lazur - mold-ripened cheese revealed 17 odor-active compounds. The highest flavor dilution factor (FD) has been obtained for methanethiol (2048) with burnt odor note and for 2(3)-methyl butanoic acid (2048) with cheesy, pungent odor. Further quantitation of 15 most aroma-active compounds allowed for calculation of their odor activity values (OAV)...
February 1, 2017: Journal of Agricultural and Food Chemistry
Alison G Simon, DeEtta K Mills, Kenneth G Furton
Volatile organic compounds (VOCs) in the headspace of the fungus Raffaelea lauricola have been monitored and identified over a twenty-eight day growth period. R. lauricola is an invasive and phytopathogenic fungus that was first identified in the United States in the mid-2000s. It is believed to be spread by a host beetle, Xyleborus glabratus, and is detrimental both to wild members of the Lauraceae family and to commercial avocado groves particularly in the Southeastern region of the country. The fungus causes the fatal laurel wilt disease, a result of the host tree shutting down its vascular system in order to halt the spread of the fungus...
March 3, 2017: Journal of Chromatography. A
Die Gao, Dan-Dan Wang, Qian Zhang, Feng-Qing Yang, Zhi-Ning Xia, Qi-Hui Zhang, Chun-Su Yuan
A method based on molecularly imprinted solid-phase microextraction (MIP-SPME) coupled with liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) was developed for the detection of luteolin and its metabolites in vivo. The MIP-SPME fibers were first fabricated by dopamine and silane, and then luteolin MIPs-coated fibers were successfully prepared using luteolin, acrylamide (AM), and ethylene glycol dimethacrylate (EGDMA) as the template, functional monomer and cross-linker, respectively...
February 3, 2017: Journal of Agricultural and Food Chemistry
Brian Waters, Kenji Hara, Natsuki Ikematsu, Mio Takayama, Masayuki Kashiwagi, Aya Matsusue, Shin-Ichi Kubo
A headspace solid-phase microextraction (HS-SPME) technique was used to quantitate the concentration of volatile hydrocarbons from the blood of cadavers by cryogenic gas chromatography-mass spectroscopy. A total of 24 compounds including aromatic and aliphatic volatile hydrocarbons were analyzed by this method. The analytes in the headspace of 0.1 g of blood mixed with 1.0 mL of distilled water plus 1 µL of an internal standard solution were adsorbed onto a 100-µm polydimethylsiloxane fiber at 0°C for 15 min, and measured using a GC-MS full scan method...
January 22, 2017: Journal of Analytical Toxicology
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