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Applications of laser spectroscopy to analytical chemistry, environmental monitoring and medicine

Johansson, Thomas LU (2002) In Lund Reports on Atomic Physics
Abstract (Swedish)
Popular Abstract in Swedish

Det ljus som vi vanligen ser, har spritts av objekten i vår omgivning. Ett annat ljusfenomen är fluorescens, som kan användas inom olika områden för analys av prover. Olika substanser ger skilda fluorescensprofiler. Om dessa inte helt överlappar varandra kan substanserna särskiljas. Områden, där ljusdiagnostik har använts inom ramen för detta arbete, är kemisk analys, miljömätteknik och cancerdiagnostik. Likaså har ljus använts för cancerbehandling.



Inom analytisk kemi används många olika detektionsmetoder. Här har i huvudsak laserinducerad fluorescens använts inom separationstekniken kapillärelektrofores. I denna teknik används mycket tunna rör (kapillärer) för separation av... (More)
Popular Abstract in Swedish

Det ljus som vi vanligen ser, har spritts av objekten i vår omgivning. Ett annat ljusfenomen är fluorescens, som kan användas inom olika områden för analys av prover. Olika substanser ger skilda fluorescensprofiler. Om dessa inte helt överlappar varandra kan substanserna särskiljas. Områden, där ljusdiagnostik har använts inom ramen för detta arbete, är kemisk analys, miljömätteknik och cancerdiagnostik. Likaså har ljus använts för cancerbehandling.



Inom analytisk kemi används många olika detektionsmetoder. Här har i huvudsak laserinducerad fluorescens använts inom separationstekniken kapillärelektrofores. I denna teknik används mycket tunna rör (kapillärer) för separation av substanser med hjälp av ett elektriskt fält. För detektion i dessa kapillärer behövs en känslig metod och fluorescens kan då användas. För effektiv ljusinsamling användes optiska fibrer vilket gav en högre känslighet med en faktor 10. En annan analysmetod inom analytisk kemi är att med ljus belysa svävande droppar innehållande substansen av intresse. Även här utnyttjas fluorescenstekniken för detektion. Ett exempel på ett sådant experiment är att undersöka fettceller med avseende på deras fettsyreproduktion. Vid en tredje typ av undersökning studerades vilka betingelser som behövs för att kristallisering av protein skall ske. Detta undersöktes med hjälp av ljusspridningsteknik.



Fluorescens användes också för undersökning av algbeväxning på historiska byggnader som Lunds domkyrka och Parmas katedral. För att kunna mäta på alla svåråtkomliga ställen användes en metod för mätning på långt avstånd. Här skickas en laserpuls iväg och fluorescensen samlas in med hjälp av ett teleskop. Med denna metod kan alger liksom andra substanser på byggnadsfasader detekteras. Samma system användes för att mäta alghalten och organiska föroreningar i Medelhavet utanför Italiens västkust. Här riktades laserstrålen rakt ner i havet från ett undersökningsfartyg, och fluorescensen från olika djup samlades in. (Less)
Abstract
In this thesis spectroscopic techniques have been used in the fields of analytical chemistry, environmental and medical applications. In analytical chemistry, laser induced fluorescence was used to image the separation of substances during capillary electrophoresis. Here, an optical fibre imaging technique facilitated a higher sensitivity compared with a lens imaging technique. The motion of the substances was also monitored. In a similar experiment, laser induced fluorescence was used to image substances that do not exhibit fluorescence. Levitated drops have also been used as a wall-free cuvette during the study of fat-cell behaviour and protein precipitation, where laser induced fluorescence detection was used in the first part and light... (More)
In this thesis spectroscopic techniques have been used in the fields of analytical chemistry, environmental and medical applications. In analytical chemistry, laser induced fluorescence was used to image the separation of substances during capillary electrophoresis. Here, an optical fibre imaging technique facilitated a higher sensitivity compared with a lens imaging technique. The motion of the substances was also monitored. In a similar experiment, laser induced fluorescence was used to image substances that do not exhibit fluorescence. Levitated drops have also been used as a wall-free cuvette during the study of fat-cell behaviour and protein precipitation, where laser induced fluorescence detection was used in the first part and light scattering detection in the second part.



For environmental monitoring a lidar (light detection and ranging) system was used. Here, measurements have been performed at different monumental buildings to detect both biodeteriogen invasion and protective treatment. The system was also moved onto a ship for experiments in the Mediterranean Sea. Laser induced fluorescence was here used for monitoring of chlorophyll contents in the seawater together with distributed organic matter (DOM). With the use of depth resolved measurements, the water absorption was studied.



In medical applications, laser induced fluorescence techniques have been used for spectral imaging of human normal and tumour tissue. For the treatment of the tumours, photodynamic therapy was employed. Three to six optical fibres, connected to a diode laser, were used and inserted in the tumour tissue. A sensitising agent was utilised to demarcate tumour tissue by fluorescence, and also to induce cell death. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Prof. van den Bergh, Hubert, Ecole Polytechnique Fédéral de Lausanne, Switzerland
organization
publishing date
type
Thesis
publication status
published
subject
keywords
fluorescence, spectroscopic techniques, fluorescence imaging, capillary electrophoresis, acoustic levitation, remote sensing, interstitial photodynamic therapy, multivariate analysis, Laserteknik, Laser technology, tissue optics, medical imaging, Fysicumarkivet A:2002:Johansson
in
Lund Reports on Atomic Physics
pages
228 pages
publisher
Department of Physics, Lund University
defense location
Sölvegatan 14, Hall B
defense date
2002-10-04 10:15
external identifiers
  • other:ISRN: LUTFD2(TFAF-1049)1-65(2002)
ISSN
0281-2762
ISBN
ISBN 91-628-5369-4
language
English
LU publication?
yes
id
f23b884d-dc53-41fe-8ec7-cbd9ec776d5b (old id 464989)
date added to LUP
2007-09-28 10:14:51
date last changed
2016-09-19 08:44:58
@phdthesis{f23b884d-dc53-41fe-8ec7-cbd9ec776d5b,
  abstract     = {In this thesis spectroscopic techniques have been used in the fields of analytical chemistry, environmental and medical applications. In analytical chemistry, laser induced fluorescence was used to image the separation of substances during capillary electrophoresis. Here, an optical fibre imaging technique facilitated a higher sensitivity compared with a lens imaging technique. The motion of the substances was also monitored. In a similar experiment, laser induced fluorescence was used to image substances that do not exhibit fluorescence. Levitated drops have also been used as a wall-free cuvette during the study of fat-cell behaviour and protein precipitation, where laser induced fluorescence detection was used in the first part and light scattering detection in the second part.<br/><br>
<br/><br>
For environmental monitoring a lidar (light detection and ranging) system was used. Here, measurements have been performed at different monumental buildings to detect both biodeteriogen invasion and protective treatment. The system was also moved onto a ship for experiments in the Mediterranean Sea. Laser induced fluorescence was here used for monitoring of chlorophyll contents in the seawater together with distributed organic matter (DOM). With the use of depth resolved measurements, the water absorption was studied.<br/><br>
<br/><br>
In medical applications, laser induced fluorescence techniques have been used for spectral imaging of human normal and tumour tissue. For the treatment of the tumours, photodynamic therapy was employed. Three to six optical fibres, connected to a diode laser, were used and inserted in the tumour tissue. A sensitising agent was utilised to demarcate tumour tissue by fluorescence, and also to induce cell death.},
  author       = {Johansson, Thomas},
  isbn         = {ISBN 91-628-5369-4},
  issn         = {0281-2762},
  keyword      = {fluorescence,spectroscopic techniques,fluorescence imaging,capillary electrophoresis,acoustic levitation,remote sensing,interstitial photodynamic therapy,multivariate analysis,Laserteknik,Laser technology,tissue optics,medical imaging,Fysicumarkivet A:2002:Johansson},
  language     = {eng},
  pages        = {228},
  publisher    = {Department of Physics, Lund University},
  school       = {Lund University},
  series       = {Lund Reports on Atomic Physics},
  title        = {Applications of laser spectroscopy to analytical chemistry, environmental monitoring and medicine},
  year         = {2002},
}