Hn. Li et Yx. Ci, DETERMINATION OF SULFONAMIDES WITH FLUORESCENT INCLUSION COMPLEX OF CARBONIC-ANHYDRASE AND DANSYLAMIDE, Chinese Science Bulletin, 43(13), 1998, pp. 1085-1090
A new fluorimetric method for determination of sulfonamides was descri
bed based on the formation of a fluorescent inclusion complex of carbo
nic anhydrase(CA) with dansylamide (DNSA). The binding of DNSA to CA r
esulted in an enhancement in the fluorescence emission at 460 nm with
excitation at 280 nm. Dissociation constants were determined for the c
arbonic anhydrase-sulfonamide complexes. Linear calibration graphs of
sulfonamides were obtained within a concentration range of 0-0.058 mu
g/mL for DNSA; 0-0.344 mu g/mL for sulfanilamide (SAN) and 0-0.286 mu
g/mL for P-toluene-sulfonamide (PTSN). The relative standard deviation
s were within 1.8%-4.2%. Limits of detection for DNSA, SAN and PTSN we
re 0.84, 19.5 and 6.1 ng/mL, respectively. The method was applied to t
he determination of sulfonamides in cow milk at ng/mL level.