Suggested procedures for sample treatment of human biological materials

SUGGESTED PROCEDURES FOR SAMPLE TREATMENT OF HUMAN BIOLOGICAL MATERIALS 

Suggested sample treatment methods which could be satisfactorily employed for specific human biological material prior to trace element determinations by different instrumental techniques are outlined below  

The ground samples of enamel and dentin can often be used directly for measurements by NAA, GF-AAS and other techniques which employ solid sampling. It is, however, necessary to dissolve the samples for measurements by other instrumental analytical techniques. Enamel contains very low amount of organic matter and can be dissolved using a single mineral acid. It is usually necessary to eliminate the organic matter from dentin when various dry or wet ashing techniques can be used. 

Accurately weigh the sample of enamel and transfer to a thoroughly cleaned Erlen-meyer flask. Add 3 mL of 6N nitric or hydrochloric acid and warm slowly at a low heat till a clear solution is obtained. Boil for a few minutes, cool and make up to volume with ultrapure water. 

The dry ashing of dentin samples can be carried out in a muffle furnace at a temperature of 450°C. However, it Is best to ash the samples in a low temperature oxygen plasma when volatile elements are to be determined in these samples. The following procedure can be recommended  

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