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.

Report Date:

1988-02-01

Pagination or Media Count:

1.0

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 OPAmercaptoethanolbuffer 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