Sample Preparation for assaying Copper/Lead/Zinc/Iron/Cadmium by AA:
- Weight 0.1 – 0.25 g of sample into a 300 ml tall form beaker
- Add 5 ml Conc. HCL + 5ml Conc. HNO3. Place samples on a padded hotplate in a fume-hood. Turn the hotplate from 1 switch to 2 switches.
- Bring to dryness. Avoid sample spitting by moving the sample to the cooler areas of the hotplate when nearing completion of the digestion.
- Remove and place on the shelf in front of the fume and allow to cool.
- Add 30 – 40 ml distilled water by rinsing the beaker sides down. Add 5 ml Conc. HCL and cover with a watch glass.
- Bring to a boil on a bare hotplate set on two switches.
- Remove and cool by pulling the fume hood sash down. Rinse watch glasses with distilled water and then under warm tap water.
- Transfer to a 200 ml volumetric flask. Rinse the beakers sides and funnel well with distilled water.
- Bulk to the line with distilled water.
- Mix 10 times by inverting. Ensure the bubble travels the length of the flask.
*READ SAMPLES USING THE ATOMIC ABSORPTION SPECTROPHOTOMETER
(Refer to the MANUAL for operation)
NOTES:
- Confirm beaker order prior to weighing and 200 ml flask order prior to transferring.
- Cu Con Samples have the tendency to spit when bringing to the dryness stage.