Organophosphate Nerve Agent Metabolites (OPNA) in Urine

Brief Description

This LC-MS-MS method is for the detection of metabolites excreted in urine after exposure to organophosphate nerve agents sarin (GB), soman (GD), cyclohexylsarin (GF), Russian VX (rVX) and VX. The method utilizes isotopically labeled standards to detect and quantify metabolites GB acid (methylphosphonic acid, isopropyl ester), GD acid (methylphosphonic acid, 1, 2, 2-trimethylpropyl ester), GF acid (methyl phosphonic acid, monocyclohexyl ester), rVX acid (methyl phosphonic acid, 2-methylpropyl ester) and VX acid (methylphosphonic acid, monoethyl ester). 

Laboratory Unit

Chemical Threat



Specimen Collection


Collect ≥ 20 mL urine.  The minimum volume for collection is 1.5 mL of urine. Two empty containers of the same lot number should be submitted with the specimen.


Consultation is required with GPHL Emergency Response Coordinator Req 24/7 contact number: 866-782-4584.

Urine  should be stored frozen (-20°C or colder) and shipped with dry ice.

Acceptable Specimen Type(s)


Test Request

Possible Results

  • GB-Acid, GD-Acid, GF-Acid, VX-Acid, rVX-Acid 1 µg/L – 200 µg/L
  • Not detected
  • Unsatisfactory

Reference Range

Not detected

Unacceptable Conditions

  • Missing testing requisition
  • Missing minimum of 2 patient identifiers
  • No specimen received (empty collection tube).
  • Specimen leaked or was damaged or crushed in transit.
  • Wrong type of specimen submitted.
  • Patient identifier on specimen does not match that on form.
  • Low volume (< 1.5 mL Urine)
  • Failure to keep specimen frozen

Interfering Substances


Result Reported

1-3 business days

Turnaround times may be affected by the scale of the event.


No charge

LOINC/Order Codes

54097-1 (Order code: CT031100)