Physical-chemical parameters and validation of a colorimetric method for deoxycholic and ursodeoxycholic acids: kit reagent and optical sensor.
The simple and low cost β-cyclodextrin (β-CD)-phenolphthalein (PHP) inclusion complex was used for both the study of physical-chemical parameters and validation of analytical procedures for deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA) determinations in different formulations. The usefulness of this inclusion complex is proposed either in the form of kit reagent and as an original optical sensor for DCA and UDCA. The results showed that temperature had a negative effect on the equilibrium constant resulting in high negative values of enthalpy and positive values of entropy. The half-life values for DCA and UDCA measurements were 68.71 and 294.71 days, respectively. The method was validated showing limits of detection and quantification of 4.92×10(-5) mol L(-1) and 1.64×10(-4) mol L(-1) for DCA, 1.14×10(-5) mol L(-1) and 3.79×10(-5) mol L(-1) for UDCA, respectively. The developed optical sensor also showed response linearity, ease of implementation and potential application in fast screening tasks even out of the laboratory.
Lab. de Imunopatologia Keizo Asami, Universidade Federal de Pernambuco, Recife, Brazil. pabyton@yahoo.com.br
Pabyton G
PG
Cadena
Alberto N
AN
Araújo
Maria C B S M
MC
Montenegro
Maria C B
MC
Pimentel
José L Lima
JL
Filho
Valdinete L
VL
Silva
D001647:Bile Acids and Salts / Q000032:analysis; D055598:Chemical Phenomena; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003124:Colorimetry / Q000191:economics / Q000379:methods*; D003840:Deoxycholic Acid / Q000032:analysis* / Q000737:chemistry; D019277:Entropy; D007202:Indicators and Reagents / Q000737:chemistry; D055620:Optical Phenomena; D020113:Phenolphthalein / Q000737:chemistry; D011933:Reagent Kits, Diagnostic; D013696:Temperature; D013997:Time Factors; D014580:Ursodeoxycholic Acid / Q000032:analysis* / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry
D001647:Bile Acids and Salts; D007202:Indicators and Reagents; D011933:Reagent Kits, Diagnostic; D047392:beta-Cyclodextrins; D003840:Deoxycholic Acid; D020113:Phenolphthalein; D014580:Ursodeoxycholic Acid