Selecting from DataSet

[Database Administrator]

In Visual Studio, I have my DataSet filled with several static tables (they
might get changed weekly, but that's about it).

With one of these tables in the DataSet, is it possible to select distinct
items?

Ex:
I want to fill a tree with a list of job titles, and the Employee table is
filled already with all employee records. Is there a way I could do something
like this below?

DataRow[] drTitles = DataSet1.Tables["Employees"].Select("Distinct JobTitle");

(the line above will fail with "Syntax error: Missing operand after
'JOBTITLE' operator.")

I'm double posting this question. I think it is more relivant here, but this
board does not see much activity, so the question will be posted elsewhere as
well.