Unknown Substance Analysis

CPT: Call client services.
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Test Details


Identify drugs in powders, liquids, residues, etc


Immunoassay (IA); gas chromatography/mass spectrometry (GC/MS); liquid chromatography with time-of-flight mass spectrometry (LC/TOF)

Specimen Requirements


Unknown substance or residue


2 mL or 50 mg

Minimum Volume

Trace or residue


Screw-top container

Storage Instructions

Maintain specimen at room temperature.

Causes for Rejection

Urine from preservative tube


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
791358 Unknown Substance Analysis 16793-2 791359 Unknown Substance Analysis N/A
791358 Unknown Substance Analysis 16793-2 791362 Unknown Substance Analysis 16793-2

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The LOINC® codes are copyright © 1994-2018, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf