Simultaneous determination of nitrate, chloride, sulfate, and phosphate in natural waters by ion chromatography

Journal Article · · J. Environ. Qual.; (United States)

OSTI ID:6976082

Tabatabai, M A ^[1]; Dick, W A

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1. Iowa State University, Ames

Simultaneous analysis of anions in water samples is needed. Studies to evaluate the Dionex Model 10 Ion Chromatograph (IC) for simultaneous determination of NO/sub 3//sup -/, Cl/sup -/, SO/sub 4//sup 2 -/, and PO/sub 4//sup 3 -/ in water samples, including soil extracts, showed that the results by the IC method agreed closely with those obtained by the steam-distillation method for NO/sub 3//sup -/, colorimetric method using mercuric thiocyanate and ferric ammonium sulfate for Cl/sup -/, reduction and colorimetric determination as methylene blue for SO/sub 4//sup 2 -/, and colorimetric molybdenum blue method for PO/sub 4//sup 3 -/. The IC method is based on separation of the anions by a separator column containing Dionex low-capacity anion-exchange resin in the HCO/sub 3//sup -/ form and on converting the various anions to their corresponding acids by a suppressor column containing a strong acid cation-exchange resin in the H/sup +/ form. A solution 3.0 mM NaHCO/sub 3/ + 2.4 mM Na/sub 2/CO/sub 3/ is used as the eluent, and electrical conductivity is used as the mode of detection. The method is precise and accurate, and can detect as little as 0.1 mg/L of NO/sub 3//sup -/-N, Cl/sup -/, SO/sub 4//sup 2 -/-S, or PO/sub 4//sup 3 -/-P in water samples. The coefficient of variation ranged from 0.44 to 8.6% for NO/sub 3//sup -/-N, from 0.14 to 4.3% for Cl/sup -/, from 0.13 to 1.1% for SO/sub 4//sup 2 -/-S, and from 0.55 to 8.6% for PO/sub 4//sup 3 -/-P. With the IC method, the 4 anions indicated can be determined simultaneously in 2 mL of water in approximately 10 min.

• OSTI ID: 6976082
• Journal Information: J. Environ. Qual.; (United States), Journal Name: J. Environ. Qual.; (United States) Vol. 12:2; ISSN JEVQA
• 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
ABSORPTION SPECTROSCOPY
ANIONS
CHARGED PARTICLES
CHEMICAL ANALYSIS
CHLORIDES
CHLORINE COMPOUNDS
CHROMATOGRAPHY
COMPARATIVE EVALUATIONS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
ION EXCHANGE CHROMATOGRAPHY
IONS
MEASURING METHODS
NITRATES
NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
SEPARATION PROCESSES
SPECTROSCOPY
SULFATES
SULFUR COMPOUNDS
SURFACE WATERS
WATER