Abstract: The present invention provides a test apparatus and methods for the detection of pharmacologically active compounds from body fluids, in particular from saliva. The invention test apparatus prevents the aqueous solution of the analyte(s) from flowing underneath the nitrocellulose membrane and ensures that even the smallest amounts of the aqueous solution of the analyte(s) are collected and pulled into and through the test strip by capillary action. The invention test apparatus provides sensible and rapid detection of the analyte(s) in the aqueous solution.