To facilitate the discarding and recycling treatment of a sample adhered with lead by immersing the sample into a lead separating liquid for dissolving the lead, thereby separating the lead from the sample.
The sample adhered with at least the lead is immersed into the separating liquid for dissolving the lead by which the lead is separated from the sample. The lead separating liquid preferably contains the acid selected from hydrochloric acid, acetic acid, methanesulfonic acid, ethanesulfonic acid and propanolsulfonic acid at a concn. of ≥1mol/L. If these acids are used, the air pollution by the discharge of NOx which arises when nitric acid is used does not arise and there is no need for the remedy for water pollution by waste water contg. fluorine which occurs when boron fluoride is used. The other preferable lead separating liquid is prepd. by dissolving iodine into a soln. selected from methanol, ethanol, ethylene glycol, diethylene glycol and the compd. expressed by HOC2H4OC2H4OCnH2n+1. In such a case, the lead is settled as lead iodide in the final.
AISAKA TSUTOMU
SONODA NOBUO
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