Cresolphthalein

Other Names Phenolphthalein, 3, 3 -dimethyl- o-Cresolphthalein 3,3- X3-methyl-4-hydroxyphenyl)phthalide Cresolphthalein CA Index Name l(3H)-Isobenzofuranone, 3,3- iX4-hydroxy-3-methylphenyl)-CAS Registry Number 596-27-0 Merck Index Number 2576 Chemical Structure 

Chemical/Dye Class Phthalein Molecular Formula C22H18O4 Molecular Weight 346.38 pH Range 8.2-9.8 

Physical Form Buff or beige powder Solubility Slightly soluble in water soluble in ethanol UV-Visible ()imax) 566 nm, 381 mn Melting Point 223°C 

Boiling Point (Calcd.) 555.0 + 50.0°C Pressure 760 Torr Synthesis Synthetic methodsi  

Major Applications Sensors, n display device, photoresists, recording materials, imaging materials, authentication system for secure documents,i decoder system, Uthium cells, electroplating process, 19 inks,20 2i markers, toners, correction fluid, paints, 5 adhesives, floor coatings, gas leaking detector for safety in industries, toys, food storage, diapers, determination of calcium, lotions, 4 urine analysis test strips, drugs, blood analysis  

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Purification as for phthalein complexone except that it was synthesised from thymolphthalein instead of cresolphthalein. 

Polymeric pH indicators, phenolphthalein-formaldehyde (PPF) and o-cresolphthalein-formaldehyde (CPF) were synthesized with phenolphthalein and o-cresolphthalein reacted by formaldehyde under alkaline conditions, respectively. They can be immobilized in hydrolyzed cellulose diacetate membranes (HCDA) mainly due to macromolecular entrapment, and can be covalently bound to poly(vinyl alcohol) (PVA) via the considerable newly produced hydroxylmethyl groups [168,169], Phenol red (phenolsulfonphthalein) and its derivatives are commonly used for pH determination. 

Olansky, A.S., Parker, L.R., Jr., Morgan, S.L., and Deming, S.N. (1977), Automated Development of Analytical Chemical Methods. The Determination of Serum Calcium by the Cresolphthalein Complexone Method, Anal. Chim. Acta, 95, 107-133. 

Analysis. Ca gives a brick-red flame coloration, indicating that various optical spectroscopies will be effective in its determination. Ca is quantitatively determined by colorimetry down to 100 ppb using murexide or o-cresolphthalein, by atomic absorption spectroscopy (AAS) to 20 ppb, to 1 ppb by electrothermal absorption spectroscopy (ETAS), to 0.01 ppb by inductively-coupled plasma emission spectroscopy (ICPES), and to 10 ppb by inductively-coupled plasma mass spectroscopy (ICPMS). A spot test for Ca which extends to 3 ppm is provided by glyoxal bis(2-hydroxyanil). 

Thymolphthalein complexone [1913-93-5] M 720.8, m 190°(dec). Purification as for phthalein complexone except that it was synthesised from thymolphthalein instead of cresolphthalein. 

Usually, phenolphthalein-derived polymers are polymerized through the hydroxyl groups, thus destroying their well-known indicator properties. There is one example in which phenolphthalein and o-cresolphthalein 284 have been polymerized with formaldehyde to form phenol/formaldehyde type polymers, for example, 285. These polymers retain the indicating properties of the monomers with potential application in pFl test strips and optical pH sensors <2005PSA1019>. 

A series of novel polyimides were prepared from diaminophthalide 288 and four anhydrides 289 for the investigation of water-permeable membranes. Of the polymer products 290, the best permeability was associated with bulky groups (trifluoromethyls) on the polyimide chains <2005JAPS2047>. There are other variants of diaminophthalide 288 used to prepare polyimides and polyamides. A fluorinated variation 291 has been used for polyimide synthesis <2004MI979> as has 292, derived from o-cresolphthalein 284 <1999PSA455>. 

Diacetoxymercuri 0 cresolphthalein is prepared in the usual manner, more mercurous acetate being formed than with the previous derivatives. It is a yellow, granular substance, which cannot be recrystallised,... 

Kang HP, Scott MG, Joe BN, Narra V, Heiken J, Parvin CA Model for predicting the impact of gadolinium on plasma calcium measured by the o-cresolphthalein method. Clin Chem 50 741 -746,2004. 

The procedures given in sections (D), (E), (F), and (G) are intended to illustrate the preparation of a number of useful indicators. Phenolphthalein is not selected because it is available at a very low price. o-Cresolphthalein has about the same range (pH 8.2-9.8) as phenolphthalein, while th3unolphthalein is useful at pH 9.4-10.6. Both are formed by essentially the same method as phenolphthalein. 

Indicator for titrations. Phenolphthalein, methyl red, and o-cresolphthalein are dissolved in 90 per cent methanol. The useful concentration is 0.5 to 1.0 g per liter. 

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