Cresolphthalein complexon

Other Names Phenolphthalein, 3, 3 - [[ (carboxymethyl)amino]methyl]-5, 5 -dimethyl- 3,3 -5i5[A, A -fci5 (carboxyinethyl)aniinomethyl]-o-cresolphthalein 3,3 -5ii[Af,Af-di(carboxyinethyl)ainino-methyl]-o-cresolphthalein Cresolphthalein complexon Cresolphthalexon NSC 298195 Phthalein complexone o-Cresolphthalein complexon o-Cresolphthalein complexone o-Cresolphthalexon  

CA Index Name Glycine, Af,iV -[(3-oxo-l(3H)-isobenzofuranylidene) i5 [(6-hydroxy-5-methyl-3, 

1- phenylene)methylene]]fci5 [N-(carboxymethyl)-CAS Registry Number 2411-89-4 

Merck Index Number Not hsted Chemical Structure 

Chemical/Dye Class Phthalein Molecular Formula C32H32N2O12 Molecular Weight 636.60 pH Range 8.2-9.8 

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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. 

Total calcium is most frequently measured by spectrophotometry using metaUochromic indicators or dyes. Of the metaUochromic indicators that change color on selectively binding calcium, o-cresolphthalein complexone (CPC) (3, 3"-bis [ [bis-(carboxymethyl)amino] -methyl] -5", 5"-dimethylphenolphthalein) (Figure 49-3) and arsenazo III are most widely used. These methods, although less accurate and reproducible than atomic absorption spectrophotometry, have been easier to automate on chemistry analyzers. 

Corns CM. Interference by haemoglobin with cresolphthalein complexone method for serum calcium measurement. Ann Clin Biochem 1990 27 152-5. 

Corns CM, Ludman CJ. Some observations on the nature of the calcium-cresolphthalein complexone reaction and its relevance to the clinical laboratory. Ann Clin Biochem 1987 24 345-51. 

Earl RE, Feld RD, Cyanide is not needed in the cresolphthalein complexone determination of serum calcimn. Clin Chem 1982 28 1730. 

Lorentz K. Improved determination of serum calcium with 2-cresolphthalein complexone, Clin Chim Acta 1982 126 327-34. 

Moorehead WR, Biggs HG. 2-Amino-2-methyl-1-propanol as the alkahzmg agent in an improved continuous-flow cresolphthalein complexone procedure for calcium in serum. Chn Chera 1974 20 1458-60. 

Figure 4.7. (a) Two-line manifold for the spectrophotometric determination of calcium. Color reagent (o-cresolphthaleine complexone) and base are mixed and preheated in the first coil before the sample (30 xL) is injected and allowed to react in the second coil, the system being thermostated at 37°C. (b) Spectrophotometric determination of the total calcium content in serum at a sampling rate of approximately 110 samples/h. From left to right are shown a series of aqueous calcium standards containing (/) 25.0, (e) 20.0, (d) 15.0, (c) 10.0, (b) 5.0, and (a) 1.0 ppm, followed by three human serum samples, a serum pool (DSKK-K77), and the same serum pool sample with standard addition (25 p,L of a 500-ppm Ca standard plus 2.50 mL of serum pool). Each standard or sample was injected in quadruplicate. 

Postcolumn reagents PAR - 4-(2-pyridylazo)resordnol o-CPC - o-cresolphthalein complexone CAS - chrome azurol S PCV - pyrocatechol violet HQS - 8-hydroxyquinoline-5-sulfonic acid. 

Colorimetric Methods. Colorimetric techniques using calcium-compiexing reagents such as o-cresolphthalein complexone and, more recently, arsenazo 111 and methylthymol blue have been... 

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