Specimen Collection

Casual urine

Reference Intervals

GHB is produced endogenously in the body and functions as a neurotransmitter. The distinction between exogenous and endogenous GHB can be made only on the basis of the concentration of the compound. Endogenous GHB is present in urine at concentrations less than 10 mg/L and in plasma at less than 4 mg/L.

Urine samples must be collected within 12 hours of ingestion.

GHB is rapidly eliminated from the body. GHB is stable in the urine sample.

Uncertainty of Measurement: 12% at a concentration of 215 mg/L

Test only performed during normal working hours.

Also see Drug Screen (for Clinical Management) and Drug Screen (for Evidential Purposes).

Drug Screen (clinical management)

Drug Screen (Evidential Purposes)

Turnaround Time: 1 week

Performed weekly.

Please contact the Toxicology lab for urgent requests.

Assay Method

Principle : Liquid Chromatography Mass Spectrometry (LCMS)

Contact Information

The chemical pathology team can be reached via email: chemicalpathologist@adhb.govt.nz or via Lablink (09) 307 4949 ext 22000 or 09-3078995

Emails will receive priority attention from the on-call chemical pathologist. Include the patients NHI.

After-hours: contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours .

• Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
• Dr Cam Kyle : CampbellK@adhb.govt.nz ext 22052
• Dr Weldon Chiu : WeldonC@adhb.govt.nz ext. 23427
• Dr Campbell Heron : CHeron@adhb.govt.nz ext. 23427
• Dr Sakunthala Jayasinghe Saku.Jayasinghe@adhb.govt.nz
• Dr Owen Yi WenyiYi@adhb.govt.nz

Specimen Transport Instructions for Referring Laboratories

Prefer minimum of 2 mL urine

Transport ambient or cooled

Last updated at 11:42:03 16/01/2026