Determination of trace metals in biological materials by iodides extraction and atomic absorption spectrometry

Abstract

Extraction of arsenic, mercury, gold, silver, antimony, indium, bismuth, tellurium, cadmium, zinc and copper iodides with methylisobutylketone was examined in the sulfuric acid of concentrations from 0 to 15 normalities. Although, arsenic and zinc iodides were extracted from 6 to 12 normalities, extraction of other metal-iodides were carried out in more wide range of sulfuric acid concentrations almost from 2 to 12 normalities. Iron, sodium, potassium, magnesium and calcium iodides, these, being chief biological elements of inorganic substances, were not extracted in the least into methylisobutylketone layer from sulfuric acid solution. Copper and zinc were normal elements of biological materials and were extracted into methylisobutylketone layer by this procedures. The flame interferences of copper and zinc were not recognized in determinations of gold, silver, antimony, indium, bismuth, tellurium and cadmium. To investigate the influences of biological elements, mock solutions of human blood and urine were prepared. The addition of mock blood does not excessively interfere with determinations of arsenic, mercury, indium, bismuth, tellurium, cadmium, silver and antimony with the exception of gold. However, with addition of mock urine negative interferences were strongly seen in antimony determination, while in mercury, indium and silver determinations only slight interferences were observed. To examine the influences of sample preparation techniques, gold, silver, indium, cadmium and copper were treated both by wet ashing (nitric acid and sulfuric acid) and dry ashing.(ABSTRACT TRUNCATED AT 250 WORDS)