Development of a sensitive flow-injection-chemiluminescence detection method for the determination of laevodopa

Size-dependent active effect of cadmium telluride quantum dots on luminol-potassium periodate chemiluminescence system for levodopa detection

It was found that cadmium telluride (CdTe) quantum dots (QDs) with different sizes can have a great sensitizing effect on chemiluminescence (CL) emission from luminol-potassium periodate (KIO4) system. Levodopa, a widely prescribed drug in the treatment of Parkinson's disease, could inhibit luminol-KIO4-CdTe QDs CL reaction in alkaline solution. The inhibited CL intensity was proportional to the concentration of levodopa in the range from 8.0 nM to 10.0 μM. The detection limit was 3.8 nM. This method has been successfully applied to determine levodopa in pharmaceutical preparation and human urine and plasma samples with recoveries of 94.1-105.4%. This was the first work for inhibition effect determination of levodopa using a QD-based CL method.

Flow injection-chemiluminescence determination of dopamine using potassium permanganate and formaldehyde system

A simple and sensitive flow injection-chemiluminescence method for the determination of dopamine has been proposed. The method is based on the enhancing effect of dopamine on the chemiluminescence emission generated by the reaction of potassium permanganate with formaldehyde in an acidic medium. The proposed procedure allows the determination of dopamine over the concentration range of 3.1×10(-8)-1.7×10(-5) mol/L and with a detection limit of 1.0×10(-8) mol/L. The linear regression equation was F=44.4912+1.07×10(9)(*)C (correlation coefficient, r(2)=0.9998). The relative standard deviation is 2.1% for the determination of 1.0×10(-8) mol/L dopamine (n=11). The method was successfully applied to the determination of dopamine in pharmaceutical preparation with satisfactory results. The recoveries were found in the range of 96.5-101.3%.