Analysis of tea shoot catechins: spectrophotometric quantitation and selective visualization on two-dimensional paper chromatograms using diazotized sulfanilamide.
A highly specific and sensitive diazotized sulfanilamide reagent is synthesized for determination of tea catechins. The reagent is employed both as spray reagent for selective visualization of tea catechins on two-dimensional paper chromatograms (sensitivity <1 microg of d-(+)-catechin) and for their spectrophotometric quantification in the crude extracts of tea polyphenols isolated from fresh or dried tea shoots. The formation of yellow color (lambda(max) = 425 nm) between catechins and diazotized sulfanilamide was investigated and made the basis of a simple and sensitive spectrophotometric method for estimation of the total and individual catechins in different tea cultivars. At 425 nm, the absorbance was linear (r = 0.999) over the (0.4-8.0 microg/mL) concentration range of d-(+)-catechin.
Singh
H P
HP
Hill Area Tea Science Division, Institute Of Himalayan Bioresource Technology (CSIR), Palampur 176061, (HP) India. hps@csihbt.ren.nic.in
Ravindranath
S D
SD
Singh
C
C
D002392:Catechin / Q000032:analysis*; D002854:Chromatography, Paper / Q000379:methods; D005419:Flavonoids; D007202:Indicators and Reagents; D010636:Phenols / Q000032:analysis*; D018520:Plant Shoots / Q000737:chemistry; D011108:Polymers / Q000032:analysis*; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013053:Spectrophotometry / Q000379:methods; D013662:Tea / Q000737:chemistry*
D005419:Flavonoids; D007202:Indicators and Reagents; D010636:Phenols; D011108:Polymers; D013662:Tea; D002392:Catechin