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United States Department of Agriculture

Agricultural Research Service

Title: Design of a Portable Fluorometer Capable of Time-Resolved Luminescence Measurements

item Chen, Guoying

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 20, 2004
Publication Date: November 30, 2004
Citation: Chen, G. 2004. Design of a portable fluorometer capable of time-resolved luminescence measurements. Meeting Abstract.

Technical Abstract: A rugged, filter-based fluorometer was developed for time-resolved luminescence (TRL) measurements in the field. A xenon flashlamp was used as the excitation source running at 50 Hz; and a photomultiplier tube (PMT) as the photodetector. The instrument operation and data processing are controlled by a lap-top computer running a custom program developed under LabVIEW graphical environment. The luminescence intensity was digitized with a *2 µs time resolution and a 12 bit intensity resolution. The flash-to-flash intensity variation was compensated by integrating the photocurrent from a photodiode for individual flashes. The PMT was gated to overcome saturation by the intense xenon lamp flash. Important operation parameters were user selectable, such as pulse intensity, PMT gain, number of flashes to average, and TRL integration interval. The instrument performance was demonstrated by europium-sensitized TRL using oxytetracycline as a model analyte and compared to that of a commercial model. Several accessories were also built to support versatile measurement modes in liquid and solid phases, and in evanescent field.

Last Modified: 4/19/2015
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