ABSTRACT
Daunorubicin, doxorubicin and epirubicin react with EuIII to form complexes which exhibit analytically useful room temperature phosphorescence (RTP). The RTP features of the three complexes are similar and the RTP spectra completely overlap. However, their three phosphorescence decay rates are different, and these differences were utilized to analyse the time-resolved RTP data by Kalman filtering. Simultaneous quantification of all three complexes is demonstrated and a method is proposed for the simultaneous determination of the three anthracyclines in mixtures by RTP optosensing. The analytical errors observed are within +/- 5%.
Subject(s)
Antibiotics, Antineoplastic/analysis , Luminescence , Sensitivity and Specificity , Signal Processing, Computer-Assisted , Spectrum Analysis/methodsABSTRACT
A fibre optic potassium ion sensor has been developed based on reflectance measurements of the pH-dependent chromogenic crown ether 'Takagi reagent' immobilized on the non-ionic polymeric resin Amberlite XAD2. The sensor response is in the 1.5-100 mM range with a detection limit of 0.25 mM K+. The selectivity factor over sodium is 20. The proposed sensor works with a reproducibility of +/- 0.8% at the 5 mM K+ level. Advantageous design features include ease of construction, simplicity of use, reversibility, short response time (approximately 1 min) and an optimum working pH range (7.0-8.0) for biological fluids. This optical sensor was applied successfully to the direct determination of potassium in human serum. Aqueous potassium standards containing 0.13 M NaCl and a buffer of pH 8 were used for calibration.
