Service Notification: 08/05/13
Comprehensive urine screening method change.

Effective August 5, 2013, Redwood Toxicology Laboratory will change the screening method for its comprehensive prescription drug test panels to utilize the industry's most advanced, most sensitive and specific analytical method, liquid chromatography/tandem mass spectrometry (LC/MS/MS).

Specificity of LC/MS/MS can be attributed to the fact that it separates the parent mass of the analyte and further breaks it down into fragments that are specific to the analyte, known as multiple reaction monitoring (MRM), ensuring that the peak is the analyte we seek, and that background interference is minimal.

Confirmation test method will remain unchanged, and may use a combination of either LC/MS/MS or gas chromatography/mass spectrometry (GC/MS). More information about the Comprehensive Drug Test Panel, including cuttoffs and drugs detected, can be found on our website:

If you have any questions, please contact Toxicology Support Services at: 800.255.2159, press option 5.

Redwood Toxicology Laboratory

11 000 3469 REV1

At a glance:

Specimen Type

Test Name
Comprehensive Urine Test Panel (P40, P41, P42, P43, P44, P45, P46, P47, P48 & P49)

Screening Method
Liquid Chromatography / Tandem Mass Spectrometry (LC/MS/MS)

Confirmation Method
Gas chromatography/mass spectrometry (GC/MS) or Liquid chromatography/tandem mass spectrometry (LC/MS/MS)