Abstract
A trace of molybdenum in sea water is determined by atomic absorption spectrophotometryusing solvent extraction. Molybdenum (VI) is complexed with 4-benzoy1-3-methy1-1-pheny1-5-pyrazolone (BMPP) and extracted into iso-amyl alcohol. To find the optimum condition for theextraction of molybdenum, experiments are tried on the effects of pH, concentration of BMPP, and interference of divers ions.
It is shown that extraction is complete in the pH range 1.0-3.0 at 0.2w/v% BMPP concentrationand that Na, K, Sr, Ca and Mg at high concentration have no effects on the extraction butin excess of 2mg Fe (III), Cr (VI), and V (V) depress the absorbance of molybdenum makedly, probably because of complex formation or preferential extraction.
One liter of sea water in which 10ml of concentrated hydrochloric acid is added is concentratedto 200ml by heating and then filtered using Toyo Roshi No.3 filter paper. The solution adjustedto pH 2.5 by the addition of sodium acetate is placed in a separatory funnel, and then extractedwith 10ml of 0.2w/v% solution of BMPP in iso-amyl alcohol by shaking for 10min.
It is found out that the sea water samples contain 7-11μg Mo/liter and the results are agreed well with those that have previously been published.
