EQUIPMENT

  1. Thermo Jarrell-Ash Model 61E ICP
  2. Thermo Jarrell-Ash Autosampler 300
  3. 48 position rectangular sample racks
  4. Hamilton Digital Diluter
  5. 150 mL glass beakers.
  6. Watch glasses

REAGENTS

1 Nitric Acid HNO3
2 Perchloric Acid HClO4
3 Hydrochloric Acid HCl

ICP PARAMETERS
ICP WAVELENGTHS
STANDARDS

  1. These are identical with those specified in the water section pages 112 and 113.

SAMPLE PREPARATION

  1. Solid samples are weighed on an as received basis. No drying of grinding is required.
  2. Liquid samples are shaken just prior to weighing.

DIGESTION PROCEDURES

  1. Solid Samples
    1. Weigh 1 g sample into a 150 mL beaker.
    2. Add 10 mL nitric acid
    3. Add 5 mL hydrochloric acid
    4. Cover with a watch glass
    5. Heat on a hot plate until dense white fumes are observed.
    6. Allow to cool and add 10 mL of 25% hydrochloric acid.
    7. Transfer into a 100 mL volumetric flask.
    8. Dilute to volume with deionized water and mix well.
  2. Liquid Samples
    1. Weigh 5 g sample into a 150 mL beaker.
    2. Proceed as in steps 1b through 1h above.

ICP PROCEDURE

  1. Follow the manufacturer's instruction in order to initiate the plasma and the autosampler.
  2. Select WATER from the methods menu.
  3. Setup an autosampler table for the samples being analyzed.
  4. Analyze the samples using the autosampler table.
    1. This table includes calibration standards, the calibration verification standard, quality control sample, as well as client samples.
  5. If the value for any element exceeds 40 ppm in solution, dilute the sample 1 to 10 using the Hamilton digital diluter, and reanalyze.
    1. For solid samples this represents a final dilution of 1 to 1000.
    2. For liquid samples this represents a final dilution of 5 to 1000.
  6. If the value for any element exceeds 40 ppm for the 1 to 10 dilution, do an additional 1 to 10 dilution and reanalyze.
    1. For solid samples this represents a dilution of 1 to 10,000.
    2. For liquid samples this represents a dilution of 5 to 10,000.

QUALITY CONTROL

  1. Following calibration, analyze one WAT2 standard, one instrument calibration verification standard, and two quality control samples.
    1. WAT2 Standard: Values must be within 3% of the known value for K and Mo. All other elements must be within 2% of the known values.
    2. Instrument Calibration Verification Standard: All values must be within 10% of the certified values.
    3. Quality Control Samples: Values muse lie within the "advisory range" established by the supplier if these samples.

NOTES

  1. If the results need to be reported on a dry matter basis, an additional determination of per cent total solids (pages 163 and 164) will have to be made.
  2. The calculation for dry matter basis is as follows: [value(as received) ÷ % total solids] x 100 = value(dry matter basis)