Modelling of leachates from dolomitic mine tailings.

The REDEQL.EPAK computer model was used to study speciation of Pb, Cd, Zn, and Ca in leachates from dolomitic Pb mine tailings. By allowing or disallowing precipitation of solids and equilibration of the modelled leachate with atmospheric C02, comparison of fresh and aged leachates was made.

Food analysis for lead using furnace atomic absorption and a L'vov platform.

Furnace atomic absorption is a very sensitive method for determination of lead and other trace metals in a variety of samples, but it is prone to matrix interferences. A major improvement in the method is achieved by the use of a L'vov platform, a small piece of graphite placed inside the furnace tube, onto which the sample solution is pipetted. The temperature of the platform rises more slowly than that of the tube wall during the atomization cycle, and sample vaporization is delayed until the furnace atmosphere is at a high and nearly constant temperature.