Determination of formate in natural waters by a coupled enzymatic/high-performance liquid chromatographic technique

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac00168a004· OSTI ID:7014069

Kieber, D J; Vaughan, G M; Mopper, K

An enzymatic method was developed to quantify formic acid in natural water samples at submicromolar concentrations. The method is based on the oxidation of formate by formate dehydrogenase with corresponding reduction of ..beta..-nicotinamide adenine dinucleotide (..beta..-NAD/sup +/) to reduced ..beta..-NAD/sup +/ (..beta..-NADH); ..beta..-NADH is quantified by reversed-phase high-performance liquid chromatography with fluorometric detection. An important feature of this method is that the enzymatic reaction occurs directly in aqueous media, even sea water, and does not require sample pretreatment other than sample filtration. The reaction proceeds at room temperature at a slightly alkaline pH (7.5 - 8.5) and is specific for formate with a detection limit of 0.5 ..mu..M (S/N = 4) for a 200-..mu..L injection. The precision of the method was 4.6% relative standard deviation (n = 6) for a 0.6 ..mu..M standard addition of formate to Sargasso sea water. Average recoveries of 2 ..mu..M additions of formate to sea water, pore water, or rain were 103, 103, and 87%, respectively. Intercalibration with a Dionex ion chromatographic system showed an excellent agreement of 98%. Concentrations of formate present in natural samples ranged from 0.2 to 0.8 ..mu..M for Biscayne Bay sea water, 0.4 to 10.0 ..mu..M for Miami rain, and 0.9 to 8.4 ..mu..M for Biscayne Bay sediment pore water.

• Research Organization: Univ. of Miami, FL (USA)
• OSTI ID: 7014069
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 60:18; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
520200 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AQUEOUS SOLUTIONS
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CHEMICAL ANALYSIS
CHROMATOGRAPHY
DATA
DISPERSIONS
EMISSION SPECTROSCOPY
ENZYMES
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
FORMATES
FORMIC ACID
HYDROGEN COMPOUNDS
INFORMATION
LIQUID COLUMN CHROMATOGRAPHY
MIXTURES
MONOCARBOXYLIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
RAIN WATER
SEAWATER
SEPARATION PROCESSES
SOLUTIONS
SPECTROSCOPY
TRACE AMOUNTS
WATER