Flow injection-chemiluminescence determination of dopamine using potassium permanganate and formaldehyde system.
ABSTRACT 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%.
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ABSTRACT: A sensitive spectrophotometric method for the determination of dopamine was carried out without any separation steps. Bromocresol green is adsorbed on Sephadex LH-20 gel but the sorption decreases in the presence of dopamine due to ion-pair formation between bromocresol green and dopamine in solution. This attenuation was used to the microdetermination of dopamine by measurement of absorbance of the solid phase (Sephadex LH-20 gel) in a 1.0 mm cell at 625 nm. Dopamine could be determined in the concentration range of 0.4-1.6 μg mL(-1) (10-mL Sample volume) with a relative standard deviation (RSD) of 0.03% (n = 4). The detection limit was obtained, 0.26 μg mL(-1) (1.7 μM). The method was used for determination of dopamine in pharmaceutical injection sample and satisfactory result was obtained.ISRN pharmaceutics. 01/2012; 2012:216068.