Search for dissertations about: "Per J.r. Sjöberg"

Showing result 1 - 5 of 6 swedish dissertations containing the words Per J.r. Sjöberg.

2. 1. Atmospheric pressure ionisation interface considerations for micro column separation with mass spectrometric detection

   Author : Per J. R. Sjöberg; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; Analytical Chemistry; analytisk kemi;

   Abstract : Two miniaturised atmospheric pressure chemical ionisation (APCI) interfaces were developed for micro column separation and their performances were investigated in high temperature open tubular column liquid chromatography and capillary supercritical fluid chromatography (SFC). The most influential parameters, for example, the interface probe position relative to the sampling orifice and the reagent ion plasma composition, were investigated to optimise the ion current signal and stability. READ MORE

4. 2. Pressurised Fluid Extraction of Bioactive Species in Tree Barks : Analysis using Hyphenated Electrochemical Mass Spectrometric Detection

   Author : Michelle Co; Charlotta Turner; Per J.R Sjöberg; Kari Hartonen; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pressurised fluid extraction; antioxidants; DPPH; water; ethanol; antioxidant activity; antioxidant capacity; electrochemial detection; mass spektrometry; Chemistry; Kemi; Analytical Chemistry; Analytisk kemi;

   Abstract : Analytical chemistry has developed throughout time to meet current needs. At present, the interest in biorefinery is growing, due to environmental awareness and the depletion of fossil resources. Biomass from agricultural and forestry industries has proven to be excellent raw material for different processes. READ MORE

5. 3. Organic Phosphorus Compounds in Aquatic Sediments : Towards Molecular Identification with Mass Spectrometry

   Author : Heidi De Brabandere; Monica Waldebäck; Emil Rydin; Per J. R. Sjöberg; Rolf Danielsson; William T. Cooper; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; electrospray ionisation; mass spectrometry; liquid chromatography; organic phosphorus; aquatic sediment; eutrophication; sample preparation; extraction; Analytical chemistry; Analytisk kemi;

   Abstract : Phosphorus (P) regulates trophic status in most aquatic systems. However, only bioavailable P contributes to primary production. In most lakes and shallow seas, mineralisation of sediment P into its bioavailable form and its release to the water column is important for maintaining primary production. READ MORE

6. 4. Development of Methods for Analysis of Valuable Compounds in By-products from Agricultural and Forestry Industrial Sectors

   Author : Mikael E Fridén; Per J R Sjöberg; Jonas Bergquist; Marja-Liisa Riekkola; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; industry by-products; flavonoids; triterpenes; mass spectrometry; Kemi med inriktning mot analytisk kemi; Chemistry with specialization in Analytical Chemistry;

   Abstract : A growing interest in sustainable development has made efficient utilisation of starting materials and, if they occur, by-products become increasingly important. Vast amounts of by-products are generated by the forestry and food industry. READ MORE

7. 5. Organic phosphorus speciation in environmental samples : Method development and applications

   Author : Julia V. Paraskova; Per J.R. Sjöberg; Emil Rydin; William T. Cooper; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organic phosphorus; DNA; phospholipids; inositol phosphates; sediment; soil; extraction; liquid chromatography LC ; mass spectrometry MS ; Kemi med inriktning mot analytisk kemi; Chemistry with specialization in Analytical Chemistry;

   Abstract : This thesis investigates the development of new methodology for the identification and quantification of organic phosphorus compounds in environmental samples.Phosphorus is a vital element for primary production and one of the factors contributing to eutrophication. READ MORE