title: Simultaneous determination of caffeine and paracetamol by square wave voltammetry at poly(4-amino-3-hydroxynaphthalene sulfonic acid)-modified glassy carbon electrode.
abstract: Poly(4-amino-3-hydroxynaphthalene sulfonic acid)-modified glassy carbon electrode (poly(AHNSA)/GCE) was prepared for simultaneous determination of caffeine and paracetamol using square-wave voltammetry. The method was used to study the effects of pH and scan rate on the voltammetric response of caffeine and paracetamol. Linear calibration curves in the range of 10-125μM were obtained for both caffeine and paracetamol in acetate buffer solution of pH 4.5 with a correlation coefficient of 0.9989 and 0.9986, respectively. The calculated detection limits (S/N=3) were 0.79μM for caffeine and 0.45μM for paracetamol. The effects of some interfering substances in the determination of caffeine and paracetamol were also studied and their interferences were found to be negligible which proved the selectivity of the modified electrode. The method was successfully applied for the quantitative determination of caffeine and paracetamol in Coca-Cola, Pepsi-Cola and tea samples.
authors.affiliation: Department of Chemistry, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia; Department of Chemistry, University of Gondar, P. O. Box 196, Gondar, Ethiopia. Electronic address: mollatef2001@gmail.com.
authors.forename: Molla
authors.initials: M
authors.lastname: Tefera
authors.affiliation: Department of Chemistry, Samara University, P. O. Box 132, Samara, Ethiopia.
authors.forename: Alemnew
authors.initials: A
authors.lastname: Geto
authors.affiliation: Department of Chemistry, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
authors.forename: Merid
authors.initials: M
authors.lastname: Tessema
authors.affiliation: Department of Chemistry, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
authors.forename: Shimelis
authors.initials: S
authors.lastname: Admassie
mesh_terms: D000082:Acetaminophen / Q000032:analysis*; D002110:Caffeine / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D009282:Naphthalenesulfonates / Q000737:chemistry
chemical_list: C576716:4-amino-3-hydroxynapthalene-2-sulfonic acid; D009282:Naphthalenesulfonates; D000082:Acetaminophen; D002110:Caffeine; D002244:Carbon
keywords: Caffeine; Coca-Cola; Paracetamol; Pepsi-Cola and tea; Poly(4-amino-3-hydroxynaphthalene sulfonic acid); Square wave voltammetry