Sökning: "HRMS"

Visar resultat 1 - 5 av 21 avhandlingar innehållade ordet HRMS.

1. 1. From source to the environment : Strategies for identification and determination of hydroxylated polycyclic aromatic hydrocarbons in complex particulate matrices

   Författare :Rozanna Avagyan; Roger Westerholm; Conny Östman; Marja-Liisa Riekkola; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; OH-PAHs; hydroxy-PAHs; particulate matter; PM; airborne particles; combustion particles; wood combustion; suspect screening; non-target screening; high resolution mass spectrometry; HRMS; atmospheric pressure photoionization; APPI; Analytical Chemistry; analytisk kemi;

   Sammanfattning : Adverse health effects have been linked to exposure to particulate matter, and wood combustion is considered as an important source of harmful particulate matter in the urban air and environment. Hydroxylated polycyclic aromatic hydrocarbons are a group of compounds with toxic, endocrine disrupting and carcinogenic properties. LÄS MER

3. 2. Gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry methods for the determination of environmental contaminants

   Författare :Dawei Geng; Bert van Bavel; Ingrid Ericson Jogsten; Jessika Hagberg; Thanh Wang; Heidi Fiedler; Kees Olie; Örebro universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; PCDD Fs; PCBs; OCPs; PBDEs; NBFRs; APCI; MS MS; HRMS; human serum; osprey egg; Chemistry; Kemi;

   Sammanfattning : The recent developments and improvements of instrumental methods for the analyses of the environmental contaminants, especially the persistent organic pollutants (POPs), have made it possible to detect and quantify these at very low concentrations in environmental and biotic matrices.The main objective of this thesis is to demonstrate the capability of the atmospheric pressure chemical ionization technique (APCI), using gas chromatography coupled to tandem mass spectrometry for the determination of a wide range of environmental contaminants, including the POPs regulated by Stockholm Convention, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), but also the derivates of PBDEs and novel brominated flame retardants (NBFRs). LÄS MER

4. 3. Enrichment of biogenic and anthropogenic organic substances on sea spray aerosols

   Författare :Nikola Radoman; Ian Cousins; Matthew Salter; Jurgita Ovadnevaite; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Sea spray; Organic carbon; Dissolved organic matter; Phytoplankton bloom; Cationic surfactants; Perfluorinated alkyl acids; LC-MS; HRMS; Analytical Chemistry; analytisk kemi;

   Sammanfattning : The world’s oceans are the source of one of the most abundant types of natural aerosols, namely sea spray aerosols (SSA). By scattering solar radiation, SSA play a significant role in controlling the Earth’s radiation budget, while they are also involved in the formation of clouds, acting as cloud condensation nuclei (CCN). LÄS MER

5. 4. Development of GC-HRMS procedures for determination of naturally occuring polar compounds in various environmental applications

   Författare :Bodil Widell; Dag Broman; Caroline Leck; Joan Grimalt; Stockholms universitet; []
   Nyckelord :GC-HRMS; steroid hormones; amino acids; perch; size-resolved aerosol; Arctic; NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : The overall objectives of this dissertation were to gain further understanding of the two following environmentally significant issues: (i) Determination of natural steroid hormones in blood plasma from perch (Perca fluviatilis) during a reproductive cycle and to evaluate the possibility of using the steroid composition as a biomarker for early signs of endocrine disruptive effects. (ii) Determination of dissolved free amino acids in size resolved airborne particles collected over the Arctic pack ice area (>80°N) in summer and to study their overall relationship with the ocean surface microlayer as a potential source. LÄS MER

7. 5. Hidden in the Water : Development of screening strategies to identify new organic contaminants of emerging concern

   Författare :Frank Menger; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Man-made chemicals enable and sustain our modern quality of life. These chemicals can, however, become contaminants of emerging concern (CECs). There is currently a considerable lag time between release of chemicals to the environment and their identification as CECs. LÄS MER