Forensic Fluids Laboratories uses FDA approved ELISA plates for all of our drug screens. ELISA stands for Enzyme Linked ImmunoSorbent Assay.

Forensic Fluids Laboratories uses a Waters Quatro Micro LC/MS/MS and Aquity TQD, which is the most sensitive instrument available. (Click the image to open a larger picture) This MS/MS can detect lower levels than a single MS, and is also more accurate at identifying drugs.

The scientific beauty of tandem mass spectrometry is seen by the way it identifies peaks. Daughter or fragment ions in Multiple Reaction Monitoring analysis are inextricably sourced from ONE parent each. This makes this method more sensitive and accurate than single mass spectrometry. Multiple Reaction Monitoring (MRM), with tandem MS provides exceptionally clean fragment ion chromatograms for quantification. By selectively detecting a product ion of interest from a specified precursor ion, the signal-to-noise ratio is optimized, thus lowering limits of detection (LOD). The MRM analysis mode sets MS1 to pass ONE PARENT AT A TIME to the collision cell!! This single parent ion is dissociated to fragment ions and these are measured by MS2.

The scientific beauty of liquid chromatography is that it gives the laboratory the ability to analyze for many more drugs than gas chromatography (GC). Some compounds are not very amenable to GC, such as polar analytes, metabolites, and involatiles. Drugs do not need to be derivatized with liquid chromatography, like they do with gas chromatography. Getting rid of this step decreases sample preparation time in some cases by more than one hour. Sample prep for liquid chromatography may be as easy as: pipet the saliva sample, add internal standard, centrifuge and analyze.



Data collected for any daughters is therefore exclusive to the parent form which it was sourced. Co-eluting parents may be monitored which produce the exact same fragment ions with NO confounding of the data. Here at Forensic Fluids Laboratories we can identify and quantitate over 100 different drugs on our LC/MS/MS.

Why Saliva Testing?

Saliva results give you an actual drug concentration of what is in the body, at the time of the test, or a measure of impairment (for some drugs the oral fluid levels correspond to those in plasma, unlike a urine test which measures a metabolite and may not correspond with impairment at all). Think of saliva as equivalent to serum, through glands, instead of a needle. Saliva testing for ease of administration can’t be beat! A person cannot cheat or tamper with it like a urine test (no more gender issues; now you can have respect, not embarrassment, with drug testing. Saliva testing puts an end to spilled urine, no more Yuck factor). Testing can be done anywhere, anytime, with no special facilities (i.e., toilet).

With a preserved oral fluid sample (one collected and placed in a preservation buffer), you may see a “matrix” effect due to the Tween 20 in the buffer. Some labs have reduced this effect with solid phase extraction (SPE), and a variety of chemicals, such as tetrahydrofuran.