Chromotropic acid

Chromotropic acid
Chromotropic acid
Identifiers
CAS number 148-25-4 YesY
ChemSpider 60557 YesY
KEGG C11323 YesY
ChEBI CHEBI:1751 YesY
ChEMBL CHEMBL144298 YesY
Jmol-3D images Image 1
Properties
Molecular formula C10H8O8S2
Molar mass 320.30 g/mol
Acidity (pKa) 5.36, 15.6[2]
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Chromotropic acid has the formula is (HO)2C10H4(SO3H)2.

It can be used for as a reagent in the quantitative determination of the systemic herbicide, 2,4-Dichlorophenoxyacetic acid.[3]

The usefulness of this reagent in quantitative determination is the formation of a red colouration (peaking at 580 nm wavelength) when chromotropic acid in 75% sulfuric acid reacts with formaldehyde. The colouration is specific to this aldehyde and is not produced from other organic species such as ketones and carboxylic acids.

References

  1. ^ Safety (MSDS) data
  2. ^ Dawson, R.M.C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.
  3. ^ Plant Physiology Letourneau and Krog 27 (4): 822. (1952)