Sökning: "headspace gas-chromatography"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden headspace gas-chromatography.

1. 1. Determination of benzene in urine and breath for monitoring of benzene exposure

   Författare :Göran Ljungkvist; Göteborgs universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biological monitoring; benzene; breath; urine; dynamic headspace; membrane; gas chromatography; mass spectrometry; thermal desorption;

   Sammanfattning : The aim of this work was to develop and validate methods for determination of unmetabolized benzene in breath and urine. The methods were intended for the bio monitoring of benzene to assess both occupational and environmental exposure.A method was developed for the determination of benzene in end-exhaled air. LÄS MER

3. 2. Cold trapping and reinjection techniques for gas chromatography-mass spectrometry

   Författare :Sven P. Jacobsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis describes the use of cold trapping and reinjection techniques in combination with gas chromatography-mass spectrometry. A summary of different cold trap/ reinjection systems is presented. LÄS MER

4. 3. Sample preparation and analysis of metabolites from plants in the families of Cyperaceae, Poaceae and Apiaceae

   Författare :Linus Svenberg; Åsa Emmer; Jenny Lindh; Margareta Sandahl; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gas chromatography; Mass spectrometry; Ultrasound assisted extraction; Solid-phase microextraction; Volatile compounds; Allelopathy; Bioassay; Gaskromatografi; Masspektrometri; Ultraljudsassisterad extraktion; fastfas-mikroextraktion; Flyktiga ämnen; Allelopati; Bioanalys; Kemi; Chemistry;

   Sammanfattning : An important aspect of understanding how plants effect their environmentis the study of volatile compounds and how these influence interactions between plants and other living organisms. The study of these secondary metabolites from plants can be used in practical applications, such as behaviour control of insects, and is an important part in the search for novel compounds that can be used to influence the behaviour of disease spreading vectors. LÄS MER

5. 4. Applications of Solid-Phase Microextraction to Chemical Characterization of Materials Used in Road Construction

   Författare :Bing Tang; Ulf Isacsson; Xiaohu Lu; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Asphalt release agents; Petroleum oils; Vegetable oils; Bituminous sealants; Bitumen; Emissions; Monocyclic aromatic hydrocarbons; Polycyclic aromatic hydrocarbons; Fourier Transform Infrared Spectroscopy - Attenuated Total Reflectance; Gel Permeation Chromatography; Mass Spectrometry; Gas Chromatography - Mass Spectrometry; Thermogravimetric Analysis; Headspace; Solid-phase microextraction; Calibration.; Building engineering; Byggnadsteknik;

   Sammanfattning : Environmental and health aspects of road materials have been discussed for a long time, mostly regarding bitumen and bitumen fumes. However, just a few studies on other types of road materials have been reported. LÄS MER

7. 5. Aroma Partition and Release from Soft Drinks, Jam, and Jellied Sweets

   Författare :Annika Hansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gas chromatography; aroma; gel; model mouth; partition coefficient; release; citric acid; pectin; in-nose; sugar; proton-transfer reaction mass spectrometry; soft drink;

   Sammanfattning : The research described in the present thesis was focused on the influence of food ingredients and structures on the partition and release of aroma compounds from model systems such as soft drinks, jam, and jellied sweets. The effects on aroma release were studied during both static and dynamic conditions, the latter by both model mouth and in-nose measurements. LÄS MER