Weigh a small amount of sample in a beaker.

Add Hydrochloric acid solution to the sample and mix. ( Volume of acid used must be 50 times the mass of the sample. ).

Shake for 1 minute at 37oC to make sure complete mixing.

Adjust pH to about 1 – 1.5 using Hydrochloric acid solution added dropwise.

Cover mixture to protect from light.

Place the mixture on a shaker or agitator.

Filter mixture by using a membrane filter ( Ex. whatman filter paper ).

Place filtrate on test tubes ready for AAS reading.

Read absorbances of atleast 3 the standard solutions for each of the 8 elements.

Read also absorbances of samples and blank on a Spectrophotometer at appropriate wavelength using 1 cm cuvette. Note that each of the eight (8) elements require different wavelengths.

Prepare calibration curve from absorbance readings of standard solutions against their corresponding concentrations.

Calculate the soluble Antimony, Arsenic, Barium, Cadmium, Chromium, Lead, Mercury & Selenium contents using Linear regression.

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