Browsing by Subject "indoor air"
Now showing items 1-2 of 2
-
(2021)Interest towards indoor air quality has increased for several decades from human health perspective. In order to evaluate the quality of indoor air in terms of volatile organic compound (VOC) levels, robust analytical procedures and techniques must be used for indoor air VOC measurements. Since indoor building materials are the greatest source of indoor VOC emissions, same kind of procedures must be used for analysis of emission rates from building materials and their surfaces. Theory part of this thesis reviews background of VOCs and human health, legislation and guideline values, common building materials with emissions and used sampling techniques/approaches for indoor air sampling and surface material emission rate sampling & analysis. Discussed sampling techniques include, for example, material emission test chambers, field and laboratory test emission cells, solid phase microextraction (SPME) fibre applications and Radiello passive samplers. Also new innovative approaches are discussed. Used common analysis instruments are Gas Chromatography (GC) with Mass Spectrometer (MS) or Flame Ionization Detector (FID) for VOCs and High-Performance Liquid Chromatography-Ultraviolet/Visible light detector (HPLC-UV/VIS) for carbonyl VOCs (e.g. formaldehyde) after suitable derivatization. Analytical procedures remain highly ISO 16000 standard series orientated even in recent studies. In addition, potential usage of new modern miniaturized sample collection devices SPME Arrow and In-tube extraction (ITEX) used in experimental part of this thesis are discussed as an addition to indoor air and VOC emission studies. The aim of the experimental part of this thesis was to develop calibrations for selected organic nitrogen compounds with SPME Arrow and ITEX sampling techniques and test the calibration with indoor and outdoor samples. A calibration was successfully carried out with SPME Arrow (MCM-41 sorbent), ITEX (MCM-TP sorbent) and ITEX (Polyacrylonitrile (PAN) 10 % sorbent) with permeation system combined with GC-MS for the following selected organic nitrogen compounds: triethylamine, pyridine, isobutyl amine, allylamine, trimethylamine, ethylenediamine, dipropyl amine, hexylamine, 1,3-diaminopropane, 1-methyl-imidazole, N, N-dimethylformamide, 1,2-diaminocyclohexane, 1-nitropropane and formamide. The overall quality of the calibration curves was evaluated, and the calibrations were compared in terms of linear range, relative standard deviation (RSD) % for accepted calibration levels and obtained Limits of Detection (LOD) values. Also, ways to improve the calibrations were discussed. The calibration curves were tested with real indoor and outdoor samples and quantitative, as well as semi-quantitative, results were obtained.
-
(2020)Microbial volatile organic compounds are emitted by diverse set of microbial organisms and they are known to cause health hazards when present in indoor air. Early detection of fungal contaminated buildings and species present is crucial to prevent health problems caused by fungal secondary metabolites. This thesis focuses on analysing emission profiles of different insulation materials and fungal cultures, which allows, in further studies, to develop efficient new ways to detect fungi from contaminated buildings. Studied insulation materials consisted of cellulose and glass wool, which were analysed in multiple different conditions. Humidity of atmosphere was varied between 0-10 microliters and temperature was varied between 30°C and 40°C. In fungal emission profile study 24 different cultures were analysed in two different atmospheres, ambient and micro- aerophilic, and in multiple different inoculums. Analysis for both insulation materials and fungal cultures was done using headspace solid phase microextraction Arrow -tool and headspace in tube extraction –tool together with gas chromatography – mass spectrometry. One goal for this thesis was also test suitability of these methods for detection of fungal secondary metabolites. Comprehensive fungal emission profiles were successfully formed and new information from behaviour of insulation materials in different settings was found. In addition, new information about analysis methods and fungal behaviour in different atmospheres was found. Headspace solid phase microextraction Arrow with gas chromatography – mass spectrometry was found to be efficient, sensitive and timesaving method for indoor air study purposes. There were also many potential fungal culture specific biomarker compounds found for further study purposes.
Now showing items 1-2 of 2