A confirmatory test which uses the chromatography technology specified in Regulation .07 of this chapter shall be required subsequent to each test that produces positive results for any of the drugs listed in Regulation .06 of this chapter or any drug which has been added to the list. Protocols that double-screen are permitted only if test results which are positive on both screens are confirmed positive with GC-MS before reporting a positive test. Protocols that result in one negative screening test shall be reported as a negative test.