Determination of tannic acid after precipitation with bovine serum albumin by visible light scattering in a flow injection system

Research paper by Tzong-Jih Cheng, Hsien-Yi Hsiao, Chien-Yu Chung, Po-Chung Chen, Richie L. C. Chen

Indexed on: 18 Mar '10Published on: 18 Mar '10Published in: Microchimica Acta


Tannic acid can form a precipitate with bovine serum albumin (BSA), and this was explored for its determination using a flow injection system along with detection via light scattering at 600 nm. The results on light scattering are confirmed using a particle sizing method. Scattering signals are negligible compared to the background generated by BSA in solutions with a pH of <4 or >8. Any precipitates on the wall of the flow cell pipeline were effectively removed by using a sodium dodecyl sulfate washing solution. The analytical range is from 70 to 250 µgmL-1 of tannic acid. The results imply that increasing BSA concentrations will enhance sensitivity and analytical ranges. The system can be used in solutions of pH values between 5 and 7. The results correlated closely (r2 > 0.97) with those obtained by the ferrous tartrate method when analyzing a single tannic acid and two tea tannins.