Bromoform (CHBr3)
Definition
Tribromomethane, density 2.89 g/cm3, historically the standard heavy-separation liquid. Now largely displaced by sodium polytungstate because of its toxicity and regulatory requirements, but still cited in older forensic geology literature.
- Formula
- CHBr3
- Density
- 2.89 g/cm3
- Class
- Heavy separation liquid
- Status
- Largely replaced by sodium polytungstate
- Field
- Forensic geology, soil examination
Common questions
Why was bromoform replaced in forensic mineral separation?+
Sodium polytungstate is non-toxic, water-soluble, and its density can be tuned by dilution, while bromoform is a suspected carcinogen with strict handling and disposal rules most labs now avoid.
What does bromoform's density value mean for mineral separation?+
Minerals denser than 2.89 g/cm3 sink and lighter ones float, splitting a soil or sediment sample into heavy and light mineral fractions for comparison between a crime scene and a suspect sample.
Related terms
- ATi Index
- Apatite to Tourmaline index: [apatite/(apatite + tourmaline)] x 100. Low values indicate advanced weathering or sediment recycling because apatite is dissolved by...
- Heavy Minerals
- Minerals with density greater than 2.85 g/cm3, separated from a soil or sediment by a heavy liquid. They typically form 0.1-5% of...
- Provenance
- The documented origin of a media file: the device that captured it, the time and location of capture, the chain of custody...
- Sodium Polytungstate (SPT)
- An aqueous inorganic salt solution used as a non-toxic alternative to bromoform for density separation. Density is tunable by concentration; the 2.85-2.90...
- ZTR Index
- Zircon-Tourmaline-Rutile index: [(zircon + tourmaline + rutile)/total transparent non-opaques] x 100. High values mark texturally and chemically mature sediments that have lost...