[zaid]

Hi ...
there is a specific method for thallium test ?

[Arkcon]

You can probably find canonical spot tests for thallium in collections of Feigl's Spot Tests.  For a more recent source, here's a reference:  http://link.springer.com/article/10.1007%2FBF01271518  This all depends on to what accuracy you need your answer, what possibly interferences there are, and why you don't feel like just submitting your sample for an ICP-MS.