AdipoGen o-Cresolphthalein
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Chemical. CAS 596-27-0. Formula C22H18O4. MW 346.38. Synthetic. o-Cresolphthalein is a reversible pH indicator that is colorless at pH 8.2 and red at pH 9.8. The kinetics of the reverse pathway red-purple to colorless is slow, thereby making it an appropriate molecule to check flow patterns in ducts with corrugated walls. It is also used for the colorimetric determination of calcium content via the o-cresolphthalein complexone method. Binding of calcium to o-cresolphthalein, in the presence of alkaline conditions pH 10-12, results in the formation of a red complex with an absorbance at 570-575nm. Spectral data UV-Visible lambdamax 566 nm, 381 nm 2nd. This compound is applied in sensors, display device, imaging materials, authentication system for secure documents, lithium cells, inks, markers, toners, paints, adhesives, food storage, urine analysis test strips, drugs and blood analysis.