Sökning: "GC-MS"

Visar resultat 11 - 15 av 159 avhandlingar innehållade ordet GC-MS.

1. 11. Multi-platform metabolomics assays to study the responsiveness of the human plasma and lung lavage metabolome

   Författare :Masoumeh Karimpour; Malin Nording L.; Magnus Åberg; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; LC MS; GC MS; NMR; metabolomics; metabolite; exposure; postprandial; plasma; lung lavage; BW; BW; data analysis; univariate analysis; multivariate analysis;

   Sammanfattning : Metabolomics as a field has been used to track changes and perturbations in the human body by investigating metabolite profiles indicating the change of metabolite levels over time and in response to different challenges. In this thesis work, the main focus was on applying multiplatform-metabolomics to study the human metabolome following exposure to perturbations, such as diet (in the form of a challenge meal) and exhaust emissions (air pollution exposure in a controlled setting). LÄS MER

3. 12. Environmentally Degradable Polyethylene : Effects of Additives and Environment on the Degradation and Degradation products

   Författare :Farideh Khabbaz; KTH; []
   Nyckelord :LDPE; polyethylene; oxidative degradation; photo-oxidation; thermo-oxidation; degradation products; photosensitisers; pro-oxidant; starch; master-batch; gas chromatography mass-spectrometry; GC-MS; solid phase microextraction; SPME;

   Sammanfattning : This thesis summarises and compares the influences ofdifferent additives (photosensitisers, pro-oxidants, abiodegradable filler) on blown low-density polyethylene (LDPE)films during photo- and thermal degradation with respect tochemical changes in the polymer matrices and identifieddegradation products. Additives studied were irondimethyldithiocarbamate (FeDMC), nickel dibutyldithocarbamate(NiDBC), carbon black, starch, a pro-oxidant that consisted ofmanganese stearate together with styrene butadiene rubber (SBR)or natural rubber (NR) and a master batch containing linearLDPE, starch and pro-oxidant. LÄS MER

4. 13. Liquid Membrane Techniques for Trace Metal Analysis and Speciation in Environmental and Biological Matrices

   Författare :Kuria Ndung'u; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytical chemistry; Pb and Organotin species; MMLLE; SLM; GC MS; PSA; GFAS; FAAS; ICP-MS; Speciation; DEHPA; Aliquat-336; trace metals; Cr III ; Cr VI ; Analytisk kemi;

   Sammanfattning : In this thesis, liquid-membrane-based methods for the analysis of trace metal species in samples of environmental and biological origin were developed. By incorporating extracting reagents in the membrane liquid, trace metal ions were selectively separated from humic-rich natural waters and urine samples, prior to their determination using various instrumental techniques. LÄS MER

5. 14. Analytical techniques for quality assessment of separated and commingled recycled polymer fractions

   Författare :Walker Camacho; KTH; []
   Nyckelord :recycling; hdpe; pp; blends; nylon 6.6; abs; water content; mae; gc-ms; mir; chemiluminiscence;

   Sammanfattning : Different methods for quality assessment of separated andcommingled plastics from household and electronic waste havebeen developed. Especial attention has been given tospectroscopic methods since they are non-destructive andrequire little or no sample preparation at all. LÄS MER

7. 15. Consumption and loss of commercial stabilisers in polyethylene exposed to different natural environments

   Författare :Nadejzda Haider; KTH; []
   Nyckelord :LDPE; MDPE; ultrasonic extraction; polymer additives; stabilisers; antioxidants; HALS; Irganox 1010; Irgafos 168; migration; consumption; GC-MS; additive degradation products;

   Sammanfattning : A procedure for the extraction and analysis of commercialstabilisers in low density and medium density polyethylene(LDPE and MDPE) films was developed and used to study theconsumption of stabilisers in polymers exposed to differentnatural environments. An ultrasonic technique was applied toextract HALS-3 (Chimassorb 944) from LDPE film and antioxidants(Irganox 1010 and Irgafos 168) from MDPE film. LÄS MER