Laboratory Testing Cutoffs & Methods

DRUGS OF ABUSE - SALIVA SCREENING & CONFIRMATION METHODS

• Screening Cut-off Levels and Methods
• Confirmation Cut-off Levels and Methods
• Oral Fluid Detection Times

OVERVIEW

Oral fluid testing is gaining popularity with many programs that require convenient, gender-neutral specimen collection combined with the accuracy of lab testing. RTL provides an easy and affordable lab-based testing solution for the detection of drugs of abuse in oral fluid. Oral fluid drug testing from RTL utilizes the only collection device that has a volume adequacy indicator. This indicator ensures that sufficient saliva (1 mL) is collected to prevent possible false negative results due to insufficient sample size, and to provide a meaningful quantitative result.

The oral fluid collection device also allows drug concentrations to be reported per mL of oral fluid (GC/MS & LC/MS/MS confirmations available). One (1) mL of oral fluid combined with three (3) mL of buffering agent provides four (4) mL of specimen, allowing a sufficient amount of sample for screening and confirmation procedures.

The following is an explanation of RTL's oral fluid screening and confirmation procedures/cutoff levels. The routine cutoff levels listed below may periodically change. Note: some cutoff levels may differ for your agency.

SALIVA SCREENING METHODOLOGY
Specimens collected with the oral fluid collection device are sent to Redwood Toxicology Laboratory for screening by Enzyme Immunoassay (EIA) or Enzyme-Linked Immunosorbent Assay (ELISA).

	SCREENING CUTOFF LEVELS BY EIA        cutoff levels updated periodically.
	Drugs of Abuse		EIA Cutoff
	Alcohol		.025 g/dL
	Amphetamine		50 ng/mL
	Barbiturates6		50 ng/mL
	Benzodiazepines		20 ng/mL
	Buprenorphine7		5 ng/mL
	Cocaine Metabolite (benzoylecgonine)		20 ng/mL
	Methadone		50 ng/mL
	Methamphetamine		50 ng/mL
	Opiates (codeine, hydrocodone, hydromorphone, morphine, 6-monoacetylmorphine)		40 ng/mL
	Oxycodone		40 ng/mL
	Phencyclidine		10 ng/mL
	Synthetic Cannabinoids		View details »
	THC (cannabinoids)		4 ng/mL

These oral fluid cutoffs are based upon preliminary guidelines established by the Substance Abuse Mental Health Services Administration (SAMHSA) Drug Advisory Board for drug testing of alternative matrices.

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ORAL FLUID DRUG TEST CONFIRMATION METHODOLOGY
Positive screens are confirmed by gas chromatography/mass spectrometry (GC/MS) or Liquid chromatography/tandem mass spectrometry (LC/MS/MS).

	CONFIRMATION CUTOFF LEVELS BY GC/MS        cutoff levels updated periodically.
	Drugs of Abuse		GC/MS cutoff
	Alcohol4		.025 g/dL
	Amphetamine		15 ng/mL
	Barbiturates		20 ng/mL
	Benzodiazepines5     - Alprazolam, Chlordiazepoxide, Clonazepam,       Diazepam, Flunitrazepam, Flurazepam, Lorazepam,       Miazolam, Nordiazepam, Oxazepam, Temazepam,       Triazolam		.5 ng/mL
	Buprenorphine5		1 ng/mL
	Norbuprenorphine5		5 ng/mL
	Cocaine Metabolite (Benzoylecgonine)		8 ng/mL
	Methadone		10 ng/mL
	Methamphetamine		15 ng/mL
	Opiates     - Codeine, hydrocodone,       Hydromorphone, Morphine,     - 6-monoacetylmorphine		20 ng/mL 4 ng/mL
	Oxycodone		20 ng/mL
	Phencyclidine		5 ng/mL
	Synthetic Cannabinoids		View details »
	THC (cannabinoids)		1 ng/mL

	ORAL FLUID DETECTION TIMES1
	Drugs of Abuse		Detection Time
	Alcohol		After absorption (~1 hour) blood alcohol decreases ~.02 gm%/hour
	Amphetamine		From minutes up to 48 hours
	Barbiturates		From minutes up to 48 hours
	Benzodiazepines		From minutes up to 48 hours
	Buprenorphine / Norbuprenorphine		From minutes up to 48 hours
	Methamphetamine		From minutes up to 48 hours
	Cocaine		From minutes up to 48 hours
	Opiates		From minutes up to 48 hours
	Oxycodone		From minutes up to 48 hours
	Phencyclidine		From minutes up to 48 hours
	THC (∆ - 9 THC)		From minutes up to 48 hours
	Synthetic Cannabinoids		From minutes up to 48 hours
	Methadone		From minutes up to 48 hours

1. Average detection time. Chronic exposure may lead to longer detection times.
4. Alcohol confirmed by Gas Chromatography Flame Ionization Detector (GC-FID).
5. Confirmed by Liquid chromatography/tandem mass spectrometry (LC/MS/MS).
6. Detected by Enzyme-Linked Immunosorbent Assay (ELISA).
7. Test performed by Homogeneous Enzyme Immunoassay (HEIA).

The Resource Library includes information available in our printed Reference Guide, delivered to all new clients. To download a PFD of our Reference Guide, click here.