Newly developed flow-through coulometric detector with renewable working material of glassy carbon
microbeads was fabricated and its basic electrochemical parameters were studied by flow injection
analysis using potassium ferrocyanide and hydroquinone as probes. Main advantage of the detector is its
simple construction while maintaining good electrochemical parameters and high conversion degree.
Practical application of the detector was proved by the development of new HPLC and FIA method of
thymol and sulfamethizole determination in pharmaceutical preparations. Optimal determination
conditions were found and calibration dependences were measured. A value of quantification limit
0.97mmol L1 for thymol and 0.040mmol L1 for sulfamethizole were obtained. Newly developed
methods were used for determination of the studied compounds in pharmaceutical preparations. HPLC
with spectrophotometric detectionwas used as a comparative method; results from both methods were
in good agreement.