Chiang Mai Journal of Science

Determination of p-Coumaric Acid by Using a Briggs-Rauscher Oscillating System

Paper Type	Contributed Paper
Title	Determination of p-Coumaric Acid by Using a Briggs-Rauscher Oscillating System
Author	Waqar Uddin, Saif Ullah, Shafiq ur Rehman, Gang Hu*, Muhammad Yasir Nawabi, Zhaohui Fang*, Saira Sardar and Rooh Ullah
Email	hugang@ustc.edu (Gang H.), fangzhaohui9097@163.com (Zhaohui F.)
Abstract:  This paper account a new technique for determination of tracing quantities of p-coumaric acid by its perturbation effects on a novel Briggs-Rauscher (BR) oscillator catalyzed by tetra-aza-macrocyclic Ni-complex [NiL](ClO4)2. Whereas, the ligand “L” in the complex is 5,7,7,12,14,14 -hexamethyl-1,4,8,11- tetraazacyclotetradeca-4,11-diene. In this novel-BR-system, not only the metal ion (Mn2+) catalyst was replaced by Ni-complex, but kept pH of the oscillator identical to the pH value of the human stomach (pH=2) as well. Experimental results indicated that the perturbation effect of p-coumaric acid is reflected in the quenching and regeneration of oscillations after a temporary interval called inhibition time (tin). Such tin of the system has directly proportional to the concentration of p-coumaric acid added. Thus linear regression curve over a concentration range from 6.50 × 10-5 mol/L to 2.25 × 10-4 mol/L of p-coumaric acid vs tin with a correlation coefficient 0.99 was achieved. The observed limit of detection (LOD) is 1.50 × 10-5 mol/L. The RSD calculated from 6 measurements of 1.0 × 10-4 mol/L of p-coumaric acid is 2.24 %. Some factors influencing the determination were also examined. The reaction perturbation mechanism has been proposed from the well-known FCA oscillatory mechanism. A brief explanation is that the p-coumaric acid reacts with intermediate species HOO• (hydroperoxyl radical) and the system was temporarily ceased. Not only this method is applicable to determine p-coumaric acid but also utilized to determine the other antioxidants as well.
Start & End Page	1207 - 1218
Received Date	2019-04-24
Revised Date
Accepted Date	2019-06-02
Full Text	Download
Keyword	Briggs-Rauscher, antioxidants, chemical oscillations, p-Coumaric acid, inhibitory effect
Volume	Vol.46 No.6 (November 2019)
DOI
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