Sensitive determination of synephrine by flow-injection chemiluminescence.
It was found that light emission produced by the oxidation of luminol by potassium ferricyanide in basic medium was enhanced by synephrine, an anti-obesity drug. The optimum conditions for this chemiluminescent reaction were studied in detail in a flow injection system and employed in a new, simple and rapid method for the determination of synephrine. A mechanism for this reaction is proposed, based on the chemiluminescence reaction spectra. In the optimum conditions, CL intensity is proportional to concentration of synephrine in the 0.008-1 microg/mL range. The limit of detection is 1.6 ng/mL for synephrine (3sigma), and the relative standard deviation (n = 11) is 2.6% for 0.5 microg/mL synephrine. The method was applied to the determination of synephrine in herbal products, citrus fruit and biological fluids. The recoveries were satisfactory (90-102%). The results given by the proposed method are in good agreement with those given by HPLC-UV.
Li
Qian
Q
Department of Chemistry and Chemical Engineering, Institute of Analytical Sciences, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Southwest Normal University, Beibei, Chongqing 400715, People's Republic of China.
Huang
Chengzhi
C
Huang
Yuming
Y
D002851:Chromatography, High Pressure Liquid; D005295:Ferrocyanides / Q000737:chemistry; D017022:Flow Injection Analysis / Q000379:methods*; D008163:Luminescent Measurements; D008165:Luminol / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012972:Sodium Hydroxide / Q000737:chemistry; D013578:Synephrine / Q000032:analysis*
D005295:Ferrocyanides; D012972:Sodium Hydroxide; D008165:Luminol; C031835:potassium ferrocyanide; D013578:Synephrine