HG-AAS
Definition
Hydride-generation AAS for hydride-forming elements (As, Sb, Se, Bi, Te, Sn, Ge). Sodium borohydride in acid generates the volatile hydride, which is decomposed in a heated quartz cell at about 900 degrees C to free atoms.
- Full name
- Hydride-generation atomic absorption spectrometry
- Target elements
- As, Sb, Se, Bi, Te, Sn, Ge
- Reagent
- Sodium borohydride in acid
- Atomization cell
- Heated quartz cell, about 900 degrees C
Common questions
Why is a separate hydride-generation step needed instead of standard flame AAS?+
Hydride-forming elements like arsenic and selenium give weak, poorly reproducible signals in a normal flame. Converting them to volatile hydrides first and atomizing that gas stream in a heated quartz cell removes matrix interference and pushes detection limits far lower than direct flame aspiration.
What sample types is HG-AAS typically used for in forensic toxicology?+
It is commonly applied to biological fluids and tissue digests where arsenic, antimony, or selenium poisoning is suspected, since the hydride step concentrates these trace elements enough to quantify them reliably from a small sample.
Related terms
- AAS
- Atomic absorption spectrometry. Free ground-state atoms in a vapour absorb a characteristic resonance wavelength from a hollow-cathode lamp, and Beer-Lambert converts the...
- Background Correction
- A method (deuterium continuum, Zeeman effect, Smith-Hieftje self-reversal, or high-resolution continuum-source) that subtracts non-atomic absorption (molecular bands, scatter) from the raw absorbance...
- CVAAS
- Cold-vapour AAS. Mercuric ions are reduced by stannous chloride or sodium borohydride to elemental mercury vapour, swept by argon into a quartz...
- GFAAS
- Graphite-furnace AAS, also called electrothermal AAS. A graphite tube heated electrically through a programmed ramp atomises a microlitre aliquot, giving roughly 100...
- Hollow Cathode Lamp (HCL)
- A sealed lamp whose cathode is made of the element being analysed, filled with argon or neon at low pressure. Strikes a...