1. Specimen Matrix Validation
The Toxin Zoomer is validated exclusively for human urine specimens. Validation studies establishing the assay’s analytical performance characteristics (including accuracy, precision, reportable range, and matrix suitability) were performed only on urine matrices. EBOO (Extracorporeal Blood Oxygenation and Ozonation) waste has not undergone method validation for this assay. Therefore, specimens consisting of EBOO waste cannot be processed, analyzed, or reported under this method with the same analytical validity or regulatory compliance as validated urine specimens.
2. Specimen Rejection Criteria
Specimens identified, documented, or reasonably suspected to be EBOO waste rather than urine do not meet the validated specimen requirements for the Total Tox assay.
Such specimens will be classified as TNP (Test Not Performed) due to submission of a non-validated specimen matrix. Testing will not be performed because analysis of non-validated specimen types falls outside the established performance specifications and validation scope of the assay.
3. Specimen Verification and Differentiation
Upon receipt, urine specimens are subject to specimen integrity and matrix verification procedures, which include visual inspection and quantitative creatinine measurement as part of the toxin testing workflow.
Although EBOO waste may visually resemble urine, creatinine concentration serves as a key biochemical indicator of specimen authenticity. Physiologic urine specimens typically contain measurable concentrations of creatinine within established biological ranges. In contrast, non-urine matrices such as EBOO waste are expected to demonstrate extremely low or negligible creatinine concentrations, which may indicate that the submitted specimen does not represent a valid urine matrix.
To further strengthen specimen verification procedures, the Laboratory is evaluating the implementation of additional specimen validity assessments, including urine pH and specific gravity, as part of the laboratory’s ongoing quality management and method oversight program.