| pubmed-article:18167058 | pubmed:abstractText | 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. | lld:pubmed |
