Isolation of lead from water samples and determination of Pb

This paper describes the procedures of isolating lead and strontium from the larger volume of seawater and drinking water samples that enable the determination of ²¹⁰Pb on gamma spectrometer and ^89,90Sr on liquid scintillation counter. In one procedure, lead is directly isolated from water sample on the column filled with Sr resin by binding of lead on the Sr resin column from 0.2 M HCl in water sample, and successive elution with 0.2 and 8 M HCl. In others, lead and strontium are precipitated from sample with (NH₄)₂CO₃, followed by isolation on an anion exchange column. Lead, strontium and yttrium are bound onto anion exchange column (filled with Amberlite CG-400 in nitrate form) from alcoholic solutions of nitric acid. Lead, Sr and Y are separated from Mg, Ca, K, and other elements by elution with 0.25 M HNO₃ in the mixture of ethanol and methanol. After that, strontium and yttrium are separated from lead by elution with 0.25 M HNO₃ in the mixture of ethanol and water.

The procedure with the Sr resin (direct isolation) is simpler and faster in the phase of isolation on the column in comparison with the procedure with the anion exchanger. The procedure with the anion exchanger, however, makes possible the simultaneous isolation of lead, yttrium and strontium and rapid determination of ^89,90Sr. These procedures were tested by determination of ²¹⁰Pb and ^89,90Sr in real sample. Obtained results showed that Pb can be efficiently isolated (with high recovery) from sample and activity of 6 mBq l⁻¹ of ²¹⁰Pb and higher can be determined.