Abstract. Volatile organic compounds (VOCs) play a key role in atmospheric chemistry and physics. They participate in photochemical reactions in the atmosphere, which have direct implications on climate through, e.g. aerosol particle formation. Forests are important sources of VOCs, and the limited resources and infrastructures often found in many remote environments call for the development of portable devices. In this research, the potential of needle trap microextraction and portable gas chromatography–mass spectrometry for the study of VOCs at forest site was evaluated. Measurements were performed in summer and autumn 2014 at the Station for Measuring Ecosystem-Atmosphere Relations (SMEAR II) in Hyytiälä, Finland. During the first part of the campaign (summer) the applicability of the developed method was tested for the determination of monoterpenes, pinonaldehyde, aldehydes, amines and anthropogenic compounds. The temporal variation of aerosol precursors was determined, and evaluated against temperature and aerosol number concentration data. The most abundant monoterpenes, pinonaldehyde and aldehydes were successfully measured, their relative amounts being lower during days when particle number concentration was higher. Ethylbenzene, p- and m-xylene were also found when wind direction was from cities with substantial anthropogenic activity. An accumulation of VOCs in the snow cover was observed in the autumn campaign. Results demonstrated the successful applicability of needle trap microextraction and portable gas chromatography–mass spectrometry for the rapid in situ determination of organic gaseous compounds in the atmosphere.

Film-forming amine products (FFAP) are frequently used as corrosion inhibitors in steam-water systems. To have a better understanding of their behavior in the treated system, a liquid chromatography coupled to the high-resolution mass spectrometry (LC–HRMS) method was developed. This method enabled the concurrent targeted quantitative analysis of the film-forming amine oleyl propylenediamine (OLDA) and the nontarget screening (NTS)-based analysis of potential degradation products of FFAP or other organic matter in the system. The method was applied to samples collected from an FFAP-treated industrial steam-water system. OLDA was detected at a concentration of 0.027 mg/L after the FFAP dosing in the low-pressure steam drum. A feature (a combination of mass-to-charge ratio and retention time associated with a signal intensity) prioritization workflow was designed and applied to the NTS results to focus on the potential thermal degradation products of FFAP that could affect the studied steam-water system. Six features were prioritized from a total of 4596 detected features. Structural elucidation of these features was attempted based on mass spectrometry fragmentation data. One of the prioritized features was successfully identified as 2,2′-(tridecylimino)­diethanol, presumably a degradation product of the FFAP emulsifier. Because of the chemical structure of the molecule, 2,2′-(tridecylimino)­diethanol was considered as noncorrosive to the system. Overall, the developed LC–HRMS method facilitated the efficient analysis of OLDA with a limit of quantification of 0.002 mg/L and a comprehensive monitoring of organic matter across the steam-water system, including potential degradation products of the dosed FFAP.

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Piliated (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti-SpaA-based CIB procedure could quantitatively detect 2.5 × 10 CFU/ml of pLR colonies spiked in 10 CFU/ml of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent strains for commercial purposes.

s: The paper extracted the flavor components of Hongdao Clam by using HS-SPME Technique and made an analysis of it by GC-MS. It compared the analysis results of 75 μm Carboxen/PDMS microextraction fibers and 100 μm PDMS microextraction fibers, with the result that the later one was suitable for flavour substance analysis of Hongdao Clam. Besides, by comparing the flavor components of Hongdao clam meat and soup, the thesis reached a conclusion that there are eight common ingredients in them, as well as the type and relative percentage composition of the flavor substance. This research provided a reference for the application of combining SPME and GC-MS techniques in aquatic product processing industry.