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Updated: Jul 8, 2026

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores
Published on: August 19, 2013
Fluorescence quenching method for the determination of bleomycins A5 and A2 with halofluorescein dyes
Jiangtao Liu1, Zhongfang Liu, Xiaoli Hu
1School of Chemistry and Chemical Engineering, Southwest University, Beibei, People's Republic of China.
Abstract:
In weak acidic medium, the anticancer antibiotics bleomycin A5 (BLMA5) and bleomycin A2 (BLMA2) bind with halofluorescein dyes, such as erythrosin (Ery), eosin Y (EY) and eosin B (EB), to form ion-association complexes, which causes fluorescence quenching of halofluorescein dyes. The quenching values (DeltaF) are directly in proportional to the concentrations of bleomycins over the range 0.09-2.5 microg/mL. Based on this, a fluorescence quenching method for the determination of BLMA5 and BLMA2 has been developed. The dynamic range is 0.12-2.5 microg/mL for the determination of BLMA5 and 0.09-2.0 microg/mL for BLMA2, with detection limits (3sigma) of 0.04 microg/mL for BLMA5, 0.03 microg/mL for BLMA2, respectively. It has been applied to determine the two antibiotics in human serum, urine and rabbit serum samples. The recovery is in the range 90-102%. In this work, the optimum reaction conditions and the spectral characteristics of the fluorescence are investigated. The reasons for fluorescence quenching are discussed, based on the fluorescence theory.

