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
- Naloxone |
EIA
LC-MS/MS |
5 ng/mL
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 | |||
| Ethyl Glucuronide (EtG) | EIA | 100/500 ng/mL* | |||
| Fentanyl | EIA | 1/2 ng/mL* | |||
| LSD (Lysergic Acid Diethylamide) | ELISA | 0.5 ng/mL | |||
| 6-MAM (Heroin Metabolite) | EIA | 10 ng/mL | |||
| Meperidine | EIA | 200 ng/mL | |||
| Meprobamate (Carisoprodol Metabolite) | EIA | 100 ng/mL | |||
| Methadone | EIA | 150 ng/mL | |||
| Methadone Metabolite | EIA | 100 ng/mL | |||
| Methaqualone | EIA | 300 ng/mL | |||
| Mitragynine (Kratom) | EIA | 50 ng/mL | |||
| Opiates (Morphine and Codeine) | EIA | 300 ng/mL | |||
| Oxycodone | EIA | 100 ng/mL | |||
| Phencyclidine (PCP) | EIA | 25 ng/mL | |||
| Propoxyphene | EIA | 300 ng/mL | |||
| THC (Cannabinoids) | EIA | 20/50 ng/mL* | |||
| Tianeptine | LC-MS/MS | 10 ng/mL | |||
| Tramadol | EIA | 200 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 - Naloxone |
0.5 ng/mL 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 | |||
| Ethyl Sulfate (EtS) | 25 ng/mL | |||
| Fentanyl | 0.5 ng/mL | |||
| GHB | 10,000 ng/mL | |||
| Gabapentin/Pregabalin | 250 ng/mL | |||
| Marijuana Metabolite (THC-COOH) | 5 ng/mL | |||
| Methadone/ Methadone Metabolite (EDDP) |
100 ng/mL | |||
| Methylphenidate | Qualitative | |||
| Mitragynine | 1 ng/mL | |||
| Nalbuphine | Qualitative | |||
| Opiates - Total Morphine - 6-MAM - Hydrocodone - Hydromorphone - Oxycodone - Oxymorphone - Noroxycodone - Codeine |
100 ng/mL 5 ng/mL 100 ng/mL 100 ng/mL 50 ng/mL 50 ng/mL 50 ng/mL 100 ng/mL |
|||
| Pentazocine | Qualitative | |||
| Phencyclidine (PCP) | 5 ng/mL | |||
| Propoxyphene | 200 ng/mL | |||
| Sedative/Hypnotic Agents - Carisoprodol - Meprobamate - Zolpidem - Carboxyzolpidem |
100 ng/mL 100 ng/mL 1 ng/mL 10 ng/mL |
|||
| SSRIs - Flouxetine - Norfluoxetine - Citalopram - Sertraline - Norsertraline - Paroxetine |
Qualitative Qualitative Qualitative Qualitative Qualitative Qualitative |
|||
| Tianeptine | 10 ng/mL | |||
| Tramadol - O-desmethyl-cis-tramadol - N-desmethyl-cis-tramadol - Venlafaxine - O-desmethyl-venlafaxine |
Qualitative Qualitative Qualitative Qualitative |
|||
| Trazodone - m-CPP - OH-mCPP - OH-trazadone |
Qualitative Qualitative Qualitative |
|||
| 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 |
|||
| Ylones - Methylone - Butylone - Ethylone - Pentylone - α-PVP - MDPV - Eutylone |
Qualitative Qualitative Qualitative Qualitative Qualitative Qualitative Qualitative |
|||
- Test performed by Gas Chromatography Flame Ionization Detection.
- 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
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