ROOM-TEMPERATURE PHOSPHORESCENCE OF DANSYL CHLORIDE SOLUTION IN THE ABSENCE OF PROTECTIVE MEDIUM AND ITS MEDIUM EFFECT

A unique fluid room-temperature phosphorescence (RTP) method, which is different from the RTP methods developed previously and needs no micr oscopically ordered medium, is developed. The RTP emission of dansyl c hloride (DNS-Cl) and its amino acid derivatives can be induced directl y in aqueous system by the addition of thallium nitrate as heavy atom perturber and sodium sulfite as deoxygenator, lambda(ex)/lambda(em) = 326/574 nm. A good linearity between the RTP intensity and the concent ration of DNS-Cl in the range 2.0 x 10(-7)-1.0 x 10(-5) mol/l was obta ined with a detection limit of 1.9 x 10(-8) mol/l. A comparative study of RTP of DNS-Cl in the presence of cyclodextrins (CDs), surfactant m icelle, organic solvent and bovine serum albumin (BSA) has also been c arried out. This fluid RTP emission system of DNS-Cl is very transpare nt and stable, and can be modulated by different organic solvents. The quenching behavior of RTP by BSA presents a satisfactory linearity be tween the concentration of BSA and I-RTR which can be used in the quan titative analysis of BSA.