Helllo,
to achieve this, you will need to hack the includes\joomla.php file on the line 507. Just delete the ' - ' string there.
$this->_head['title'] = $title ? $GLOBALS['mosConfig_sitename'] . ' - '. $title : $GLOBALS['mosConfig_sitename'];
to
$this->_head['title'] = $title ? $GLOBALS['mosConfig_sitename'] . $title : $GLOBALS['mosConfig_sitename'];
Best regards,
ARTIO Support Team