Sökning: "water extraction"

Visar resultat 1 - 5 av 277 avhandlingar innehållade orden water extraction.

  1. 1. Recent Extraction Techniques with Emphasis on Supercritical Fluid Extraction and Microwave-assisted Extraction

    Författare :Cecilia Sparr Eskilsson; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analytisk kemi; Analytical chemistry; Pressurized hot water extraction; Pressurized liquid extraction; Microwave-assisted extraction; Recent extraction techniques; Supercritical fluid extraction;

    Sammanfattning : Today’s requirements of fast, reliable and selective analytical methods with minimal usage of organic solvents have accelerated the development of new, automated extraction techniques. In this thesis recent extraction techniques with emphasis on supercritical fluid extraction (SFE) and microwave-assisted extraction (MAE) were investigated. LÄS MER

  3. 2. Optimisation Challenges in Pressurised Hot Water Extraction of Polyphenols: Extraction and Degradation Kinetics

    Författare :Jiayin Liu; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Extraction kinetics; degradation kinetics; pressurised hot water extraction; optimisation; and anthocyanins; flavonoids; and polyphenols;

    Sammanfattning : Pressurised hot water is an environmentally friendly alternative to hazardous organic solvents such as methanol and heptane. One of the many applications of using pressurised hot water extraction (PHWE) is to extract polyphenols from plants. The challenges in PHWE lies with the optimisation of extraction yield. LÄS MER

  4. 3. New methods for determination of airborne pollutants : Focus on tetrabromobisphenol A, organophosphate triesters and polycyclic aromatic hydrocarbons

    Författare :Johanna Tollbäck; Ulrika Nilsson; Peter Haglund; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Air sampling; sampling methods; indoor air; SPE; SPME; extraction; dynamic extraction; online coupling; SWE; subcritical water extraction; GC MS; LC MS; organophosphate triesters; PAH; tetrabromobisphenol A; Analytical chemistry; Analytisk kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : The work presented in this thesis concerns the development and evaluation of new methods of sampling and analysis of organic pollutants in the indoor and outdoor environment. In Paper I, the development of a new method was reported for the determination of the brominated flame retardant tetrabromobisphenol A (TBBPA) in air using sampling with glass fiber filter and polyurethane foam (PUF), ultrasonic solvent extraction and liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI/MS). LÄS MER

  5. 4. Groundwater resources in hard rock coastal terrains : Insights into heterogeneity and spatial variability

    Författare :Robert Earon; Bo Olofsson; Okke Batelaan; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Crystalline Rock; Groundwater Balance; Kinematic porosity; Groundwater Recharge; Water Security; Coastal Aquifer; Land and Water Resources Engineering; Mark- och vattenteknik;

    Sammanfattning : Challenges regarding water security in hard rock coastal regions with limited soil cover are: a seasonal absence of recharge during times of peak residency, heterogeneity and variability of the fracture network, close proximity to saline water sources and spatially inconsistent storage and extraction. In areas where it is not feasible to connect residents to municipal water systems, a better understanding of the resilience of reservoirs is needed. LÄS MER

  7. 5. Analysis of Acrylamide and Anthocyanins in Foods : Extraction Optimization for Challenging Analytes

    Författare :Erik V. Petersson; Charlotta Turner; Johan Rosén; Rolf Danielsson; Marja-Liisa Riekkola; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Analysis; Extraction; Optimization; Acrylamide; Anthocyanins; Foods; Challenges; Analytical chemistry; Analytisk kemi; Analytical Chemistry; Analytisk kemi;

    Sammanfattning : In this thesis, the main concern has been to improve the reliability of different parts of the analytical workflow (Paper I, II, IV &V). Additionally, one of the resulting optimized methods was used in a real application (Paper III). Paper I-II concerned the extraction of acrylamide (AA) from foods. LÄS MER