I don't know that much about it but I was under the impression that further lab testing like the gc/ms could detect the Quick Fix and the normal screen wouldn't.
The GC/MS is not used for this purpose. An entirely different means of methodology is used instead. The GC/MS is only used to confirm drug positives and two types of adulterants (pyridine and glutaraldehyde).

For more info, read post #10 in this thread:
http://boards.cannabis.com/drug-test...-about-qf.html

With all the above pointed out, synthetic urines will have no problem clearing the SAP screen or the GC/MS because they simply contain no drug metabolites to test positive for.