Batch injection analysis utilizing modified electrodes with tetraruthenated porphyrin films for acetaminophen quantification

Batch injection analysis (BIA) utilizing amperometric detection with glassy carbon electrodes modified with [Co(TPyP){Ru(bipy)(2)Cl}(4)](TFMS)(5) (.) H2O porphyrin films were explored for acetaminophen analysis in pharmaceutical formulations. BIA is an interesting alternative for application of electrodes modified with tetraruthenated porphyrins. This sensor exhibited sharp current response peaks, rapid washout and excellent reproducibility for BIA-amperometric quantification of acetaminophen. Also, a wide linear working range (10(-4) to 10(-6) mol L-1) as well as high sensitivity and sampling frequency rate (detection limit = 1.1 x 10(-7) mol L-1, sampling frequency = 120 injections/ h) and a small Volume of analysis (100 muL/injection) was achieved. Furthermore, the proposed method permits the direct quantification of acetaminophen in many pharmaceutical products, avoiding cumbersome processes as previous separations, solvent extraction or sample filtration. The new procedure was applied to the analysis of commercial pharmaceutical products and the results were in excellent agreement with the ones obtained by spectrophotometric method. Accordingly, this amperometric method showed to be very well suited for quality control analysis and other applications with similar requirements.