Photothermal detection of trace compounds in water, using the deflection of a water meniscus
Date
1998-01-01T00:00:00Z
Supervisor/s
Journal Title
Journal ISSN
Volume Title
Publisher
Iop Publishing Ltd
Department
Type
Article
ISSN
0957-0233
Format
Free to read from
Citation
Jane Hodgkinson, Mark Johnson and John P. Dakin. Photothermal detection of trace compounds in water, using the deflection of a water meniscus. Measurement Science and Technology, 1998, Vol. 9 (8), pp 1316-1323
Abstract
Anovelphotothermaldetectorisdescribed,basedonaclosedcellsuitableforusewithlow-frequencymodulatedcontinuous-wavelightsources.Photothermalexpansioninaqueoussamplescausedthedeflectionofawatermeniscusheldacrossa200m-radiuspinhole.Displacementofthewatermeniscuswasmeasuredusingfibreopticinterferometry.Amercurydischargelamp(254nm)andalaserdiode(678nm)wereusedtodetecttoabsorptionby2ppbanthraceneand0.5ppmpotassiumpermanganateinaqueoussolution,respectively.Thetechniquewasusedtodetectdifferencesbetweenabsorptioncoefficientsinaqueoussolutionsdowntoapproximately20%ofthebackgroundabsorptionofthewateritself.