Patent ID: 7812946
Filing Date: 2010-10-12
Classification: G01J,G01N,Y02A

Abstract:
1. A method for detecting trace levels of dissolved organic compounds and leached plastic compounds in a body of water, comprising the steps of: providing a pulsating deep ultraviolet (UV) light-emitting diode; operating said deep UV light-emitting diode at an excitation of about 265 nm; selecting a focal volume in said body of water; illuminating said focal volume in said body of water with light emitted by said deep UV light-emitting diode; detecting fluorescence signals in a range of about 450 nm to 500 nm from dissolved organic compounds in said focal volume by illuminating water in said focal volume with said pulsating light-emitting diode and detecting fluorescence signals having a duration of about 50 ns with a boxcar integrator to provide gated noise rejection of said fluorescence signals, said gated noise rejection providing increased sensitivity; reducing out-of-band light-emitting diode emissions and substantially eliminating second order optical interference signals by employing optical absorption filters and optical bandpass filters to improve detection of said fluorescent signals in said range.