Metacresol purple

Last updated
Metacresol purple
M-cresol purple.svg
Identifiers
3D model (JSmol)
ChemSpider
DrugBank
ECHA InfoCard 100.017.237 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 218-960-6
PubChem CID
UNII
  • InChI=1S/C21H18O5S/c1-13-11-15(22)7-9-17(13)21(18-10-8-16(23)12-14(18)2)19-5-3-4-6-20(19)27(24,25)26-21/h3-12,22-23H,1-2H3
    Key: OLQIKGSZDTXODA-UHFFFAOYSA-N
  • CC1=C(C=CC(=C1)O)C2(C3=CC=CC=C3S(=O)(=O)O2)C4=C(C=C(C=C4)O)C
Properties
C21H18O5S
Molar mass 382.43 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Metacresol purple or m-cresol purple, also called m-cresolsulfonphthalein, is a triarylmethane dye and a pH indicator. It is used as a capnographic indicator for detecting detect end-tidal carbon dioxide to ensure successful tracheal intubation in an emergency. [1] [2] It can be used to measure the pH in subzero temperatures of saline or hypersaline media. [3]

In colorimetric capnography, the indicator is incorporated in an aqueous matrix that provides a pH just above the indicator's colour change. [4] When exposed to carbon dioxide (CO2), it undergoes a colour change from purple to yellow, because when CO2 dissolves in the matrix, it forms carbonic acid. [5]

In chemistry, it has two useful indicator ranges: [2]

See also

References

  1. ↑ "Capnography". LITFL • Life in the Fast Lane Medical Blog. Retrieved 2017-07-30.
  2. 1 2 "m-Cresol Purple 857890". Sigma-Aldrich. Retrieved 2017-07-30.
  3. ↑ Loucaides, Socratis; Rèrolle, Victoire M. C; Papadimitriou, Stathys; Kennedy, Hilary; Mowlem, Matthew C; Dickson, Andrew G; Gledhill, Martha; Achterberg, Eric P (2017). "Characterization of meta-Cresol Purple for spectrophotometric pH measurements in saline and hypersaline media at sub-zero temperatures". Scientific Reports. 7 (1): 2481. Bibcode:2017NatSR...7.2481L. doi:10.1038/s41598-017-02624-0. PMC   5449408 . PMID   28559544.
  4. ↑ Gedeon, A.; Krill, P.; Mebius, C. (1994-09-01). "A new colorimetric breath indicator (Colibri)". Anaesthesia. 49 (9): 798–803. doi: 10.1111/j.1365-2044.1994.tb04457.x . ISSN   1365-2044. PMID   7978140. S2CID   44501202.
  5. ↑ Hagberg, Carin A. (2007-02-23). Benumof's Airway Management. Elsevier Health Sciences. ISBN   978-0323070171.
Metacresol purple(pH indicator)
below pH 7.4above pH 9.0
7.4⇌9.0
Metacresol purple(pH indicator)
below pH 1.2above pH 2.8
1.2⇌2.8
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.