Accession Number : ADA191766

Title :   Real-Time Detection of Dissolved Free Amino Acids and Ammonium in Seawater.

Descriptive Note : Rept. for period ending Jan 88,

Corporate Author : NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA

Personal Author(s) : Lieberman, S H ; Wing, M R

PDF Url : ADA191766

Report Date : Feb 1988

Pagination or Media Count : 1

Abstract : Dissolved free amino acids (DFAAs) and ammonium are important nutrients in marine microbial food webs. DFAA concentrations are most often studied by high-pressure liquid chromatography of fluorescent derivatives with o-phthaldialdehyde (OPA). This procedure is laborious, requires extensive sample handling, and yields results hours or days after sampling. A fluorescent monitoring system for DFAAs, other primary organic amines, and ammonium was developed that is automated and continuous, and provides results in real-time. A gently pumped stream of seawater is reacted with an OPA/mercaptoethanol/buffer reagent and passed under the tip of a fiber optic probe supplying excitation light below 400 nm. The fluorescent signal, with a maximum at 455 nm, is transmitted by the probe to an optical multichannel analyzer employing a linear photodiode array. A plot of fluorescent intensity vs. time is recorded. The signal is linear in the range 1 to 100 nM alanine equivalents. Keywords: Food chains; DD1473 only.

Descriptors :   *AMINO ACIDS, *FOOD CHAINS, *MONITORING, *SEA WATER, *AMMONIA, AMINES, ANALYZERS, DETECTION, DISSOLVING, FLUORESCENCE, HIGH PRESSURE, INTENSITY, LINEAR ARRAYS, LIQUID CHROMATOGRAPHY, MULTICHANNEL, NUTRIENTS, OPTICAL EQUIPMENT, PHOTODIODES, PLOTTING, PUMPING, REAL TIME, SAMPLING, SIGNALS, STREAMS, YIELD

Subject Categories : Biology
      Water Pollution and Control

Distribution Statement : APPROVED FOR PUBLIC RELEASE