USGS-NWQL: I-3135:  Cadmium, total-recoverable, water, FLAA

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
Cadmium, atomic absorption spectrometric, direct
Current Revision
Revised 1985
Media
WATER
Instrumentation
Flame Atomic Absorption
Method Subcategory
Inorganic
Method Source
  USGS-NWQL
Citation
Methods for the Determination of Inorganic Substances in Water and Fluvial Sediments, Techniques of Water-Resources Investigations of the United States Geological Survey, Book 5, Chapter A1 Edited by Marvin J. Fishman and Linda C. Friedman
Brief Method Summary
Cadmium is determined by atomic absorption spectrometry by direct aspiration of the sample into an air-acetylene flame without preconcentration or pretreatment of the sample.
Scope and Application
This method may be used to analyze water and water-suspended sediment containing at least 10 ug/L of cadmium. Sample solutions containing more than 250 ug/L need either to be diluted or to be read on a less expanded scale. Sample solutions containing less than 10 ug/L need to be analyzed by the atomic absorption spectrometric chelation-extraction method, providing that the interference limits discussed in that method are not exceeded.
Total recoverable cadmium in water-suspended sediment needs to undergo preliminary digestion-solubilization by method I-3485, and recoverable cadmium in bottom material needs to undergo preliminary digestion-solubilization by method I-5485 before being determined.
Applicable Concentration Range
10-250 ug/L
Interferences
Individual concentrations of sodium (9,000 mg/L), potassium (9,000 mg/L), magnesium (4,500 mg/L), sulfate (9,000 mg/L), chloride (9,000 mg/L), nitrate (100 mg/L), iron (4 X 106 ug/L), and cobalt, nickel, copper, zinc, lead, and chromium (10,000 ug/L each) do not interfere. Greater concentrations of each constituent were not investigated.
Calcium at concentrations greater than 1,000 mg/L suppresses the cadmium absorption. At 2,000 mg per liter of calcium, the suppression is approximately 19 percent.
Quality Control Requirements
Calibrate instrument using calibration standards (CAL). Quality control samples (QCS) and laboratory blanks (LB) analyzed at a minimum of I each after every 10 samples. (Reference OFR 95-443).
Sample Handling
Container Description: 250 mL Polyethylene bottle, acid-rinsed.
Treatment and Preservation: Use unfiltered sample to rinse bottles, then acidify collected sample with HNO3 to pH < 2.
Maximum Holding Time
180 days
Relative Cost
Less than $50
Sample Preparation Methods
I-3485