Eastern Regional Research Center Site Logo
ARS Home About Us Helptop nav spacerContact Us En Espanoltop nav spacer
Printable VersionPrintable Version     E-mail this pageE-mail this page
Agricultural Research Service United States Department of Agriculture
Search
  Advanced Search
 
Programs and Projects
Subjects of Investigation
 

Title: DESIGN OF A PORTABLE FLUOROMETER CAPABLE OF TIME-RESOLVED LUMINESCENCE MEASUREMENTS

Author

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: 05/23/2013
ARS Home | USDA.gov | Site Map | Policies and Links 
FOIA | Accessibility Statement | Privacy Policy | Nondiscrimination Statement | Information Quality | USA.gov | White House