Matrix
Definition
The biological tissue or fluid (or non-biological substance) in which the analyte is suspended. The matrix decides extraction chemistry, recovery and the meaningful cut-off concentration.
- Definition
- The tissue, fluid, or substance carrying the analyte
- Examples
- Blood, urine, viscera, hair, soil
- Governs
- Extraction chemistry and recovery
- Also affects
- The meaningful cut-off concentration
Common questions
Why can the same drug concentration mean different things in different matrices?+
Distribution and stability vary by tissue, so a concentration in vitreous humour or liver does not translate directly to a blood-equivalent level, and interpretation guidelines are matrix-specific for this reason.
Why does matrix choice matter when a body is decomposed?+
Standard matrices like blood may be unavailable or degraded, forcing analysts toward alternative matrices such as bone marrow or viscera, each with its own extraction method and interpretive limitations.
Related terms
- Decontamination
- The wash protocol applied to hair or nails before extraction, intended to remove sweat, sebum and external contamination so that the assay...
- Femoral Blood
- Peripheral venous blood drawn from the femoral vein after clamping it off proximally. Considered the gold-standard antemortem-equivalent matrix because it is anatomically...
- Post-Mortem Redistribution (PMR)
- The phenomenon where drug and poison concentrations shift between body compartments after death, generally moving out of solid organs back into the...
- Viscera
- The standard set of organs and fluids collected at a suspected poisoning autopsy in India: stomach with contents, a length of upper...
- Vitreous Humour
- The gel-filled interior of the eye, anatomically isolated from hepatic and gastric post-mortem redistribution sources. In forensic toxicology of hooch deaths, vitreous...