Cleaning up procedure for Captopril determination in urine samples by a nonintrusive method

This communication suggests how the S/N ratio in the electrochemical determination of Captopril in urine samples can be simply improved. The proposed method involves unselective degradation of the proteins present in urine samples by refrigerating them down to −196°C. The separation is accomplished via ultracentrifugation at room temperature in such a way that very little manipulation of the sample occurs. This physical method is a useful tool for reducing background noise due to adsorbable products and for handling the sample as little as possible.