Matrix Destruction
Definition
Breakdown of organic tissue into water, CO2 and mineral residue so bound metals are released as free ions. Without it, AAS reads protein interference, not metal.
- Purpose
- Release protein-bound metal ions as free ions
- Products
- Water, carbon dioxide, mineral residue
- Applies to
- Toxicology sample preparation for metals
- Without it
- AAS reads protein interference, not the metal
Common questions
Why can't a metal poisoning sample go straight into an AAS instrument?+
Metals in biological tissue are typically bound to proteins, and the organic bulk both interferes with the flame or graphite furnace signal and masks the true metal concentration, so the organic matrix must be broken down first.
How does this relate to dry ashing and wet digestion?+
Dry ashing and wet digestion are the two standard methods of achieving matrix destruction, one using controlled combustion and the other using acid digestion, chosen based on the metal of interest and its volatility.
Related terms
- Acid Blank
- A parallel digestion of reagents in an empty vessel, subtracted from the sample to correct for trace metal contamination in the acids.
- Ashing Aid
- A salt (typically magnesium nitrate) added before dry ashing to fix volatile elements as less volatile salts that survive the furnace.
- Dry Ashing
- Viscera or hair is dried and incinerated in a muffle furnace at 450 to 550 degrees Celsius. Inorganic ash is dissolved in...
- Microwave-Assisted Digestion
- Closed-vessel digestion in PTFE or quartz bombs at 1200 to 1800 W, reaching 200 degrees Celsius and 1500 psi in 30 to...
- Wet Digestion
- Viscera is digested with HNO3 + H2SO4 + HClO4 (or HNO3 + H2O2) at controlled temperature. Closed-vessel microwave-assisted digestion in Teflon bombs...