How can I place a one-column-abstract in a two-column document?

This should make the trick. Important Note: This is a copy-paste from: I've just tested it

... % \author, etc

If you use the multicol package then you can easily mix different column format

\usepackage{lipsum}% for dummy text


The \twocolumn-command takes an optional argument, which will be printed in one-column-mode.