Laboratory Testing Cutoffs & Methods

The following is an explanation of RTL's urine screening and confirmation procedures/cutoff levels. The routine cutoff levels listed below may periodically change. Note: some cutoff levels may differ for your agency. The analytical methods used by RTL are scientifically accepted and approved by the U.S. Department of Health and Human Services (CMS / CLIA).

Urine Screening Methodology

In order to determine if a urine specimen is negative or positive for drugs of abuse, all specimens are initially screened by an enzyme immunoassay (EIA) procedure. Specimens that yield an EIA response below the specified cutoff are reported as "none detected." Any specimen that shows an EIA response at or above the specified cutoff is considered "presumptive positive" for a particular drug or drug class. Based on your agency's account, presumptive positive specimens may be confirmed by a second method prior to reporting positive results. (See "urine confirmation methodology" below).

Screening Methodology and Cutoff Levels —Cutoff levels updated periodically.
Drugs of Abuse Methodology Cutoff
Amphetamines (Amphetamine/Methamphetamine)
EIA 500/1000 ng/mL
Barbiturates EIA 200 ng/mL
Benzodiazepines EIA 200 ng/mL
Buprenorphine EIA 5 ng/mL
Cocaine Metabolite (Benzoylecgonine) EIA 150/300 ng/mL
Cotinine EIA 250 ng/mL
Dextromethorphan (DXM) ELISA 125 ng/mL
Ecstasy (MDMA) EIA 500 ng/mL
Ethanol EA 0.04 gm/dL
EtG EIA 100/500 ng/mL
LSD (Lysergic Acid Diethylamide) ELISA 500 pg/mL
6-MAM (Heroin Metabolite) EIA 10 ng/mL
Methadone EIA 150 ng/mL
Methadone Metabolite EIA 150 ng/mL
Methaqualone EIA 300 ng/mL
Meprobamate EIA 100 ng/mL
Opiates (Morphine and Codeine) EIA 300 ng/mL
Oxycodone EIA 100 ng/mL
Phencyclidine EIA 25 ng/mL
Propoxyphene EIA 300 ng/mL
Tramadol EIA 200 ng/mL
THC (Cannabinoids) EIA 20/50 ng/mL*

* Agency has the ability to choose cutoff levels indicated.


Urine Drug Test Confirmation Methodology

Analytical methods of confirmation include gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). The subsequent confirmatory procedures are performed on a second independent portion of the original urine specimen.

Confirmation Cutoff / LOQ Levels by Procedure—Cutoff levels updated periodically.
Drug GC-MS LC-MS/MS
Alcohol (Ethanol) .02 gm/dL
(GC-FID)1
Amphetamines
  - Amphetamine
  - Methamphetamine
  - MDA
  - MDEA
  - MDMA

250 ng/mL
250 ng/mL
250 ng/mL
250 ng/mL
250 ng/mL
Barbiturates
  - Amobarbital
  - Butabarbital
  - Butalbital
  - Pentobarbital
  - Phenobarbital
  - Secobarbital
 
200 ng/mL
200 ng/mL
200 ng/mL
200 ng/mL
200 ng/mL
200 ng/mL
Benzodiazepines
  - alpha-Hydroxyalprazolam (Alprazolam)
  - 7-Aminoclonazepam (Clonazepam)
  - 7-Aminoflunitrazepam (Flunitrazepam)
  - 2-Hydroxyethyl flurazepam (Flurazepam)
  - Lorazepam
  - alpha-Hydroxymidazolam (Midazolam)
  - Nordiazepam
  - Oxazepam
  - Temazepam
  - alpha-Hydroxytriazolam (Triazolam)
 
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
Buprenorphine/
Norbuprenorphine
0.5 ng/mL
Cocaine2 100 ng/mL
Cotinine
  - Cotinine
  - Nicotine
  - Hydroxycotinine

15 ng/mL
Qualitative
Qualitative
Dextromethorphan (DXM) 50 ng/mL
EtG 100 ng/mL
EtS 25 ng/mL
Fentanyl 5 ng/mL
GHB 10 mcg/mL
Gabapentin/Pregabalin 250 ng/mL
Marijuana Metabolite (THC-COOH) 5 ng/mL
Methadone/
Methadone Metabolite (EDDP)
100 ng/mL
Mitragynine 1 ng/mL
Opiates
  - Total Morphine
  - 6-MAM
  - Hydrocodone
  - Hydromorphone
  - Oxycodone
  - Oxymorphone
  - Noroxycodone
  - Codeine


5 ng/mL

100 ng/mL

100 ng/mL
100 ng/mL
50 ng/mL
50 ng/mL
50 ng/mL
100 ng/mL
Phencyclidine (PCP) 5 ng/mL
Propoxyphene 200 ng/mL
Tricyclic Antidepressants
  - Amitriptyline
  - Desipramine
  - Imipramine
  - Nortriptyline
  - Maprotiline
  - Doxepin

25 ng/mL
25 ng/mL
25 ng/mL
25 ng/mL
25 ng/mL
25 ng/mL
Sedative/Hypnotic Agents
  - Carisoprodol
  - Meprobamate
  - Zolpidem
  - Carboxyzolpidem



100 ng/mL
100 ng/mL
1 ng/mL
10 ng/mL

  1. Test performed by Gas Chromatography Flame Ionization Detection.
  2. Cocaine Metabolite, Benzoylecgonine


Urinalysis Adulteration/Specimen
Validity Examination

RTL's Standard Operating Procedures (SOP's) require that each urine specimen be examined for signs of adulteration. This examination includes the following

  • Physical Examination: Color, excessive foaming, excess sediments, or unusual odor are noted. If adulteration is suspected, this is noted on the final report
  • Analytical Examination: Upon request, pH, creatinine (tested by default) and specific gravity are run to aid in determining specimen validity or possible adulteration

To learn more about RTL's laboratory drug tests call:

800.255.2159

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