Diethyldithiocarbamic acid lead salt

Wash it with H2O and dry it at 60-70o, or dissolve it in the minimum volume of CHCl3 and add the same volume of EtOH. Collect the solid that separates and dry it as before. Alternatively, recrystallise it by slow evaporation of a CHCl3 solution at 70-80o. Filter the crystals, wash them with H2O until all Pb2+ ions are eluted (check by adding chromate) and then dry it at 60-70o for at least 10hours. [Lo et al. Analyt Chem 49 1146 1977.]