title: Simultaneous determination of the isomers of Ponceau 4R and Amaranth using an expanded graphite paste electrode.
abstract: A sensitive and convenient electrochemical method was developed for the simultaneous determination of the isomers of Ponceau 4R and Amaranth by an expanded graphite paste electrode (EGPE). The EGPE was prepared by mixing EG with solid paraffin. Compared with flake graphite paste and carbon paste electrodes, the EGPE showed higher electrocatalytic activity towards the oxidization of Ponceau 4R and Amaranth. Under optimal experimental conditions, the EGPE exhibited wide linear responses to Ponceau 4R and Amaranth ranging from 6×10(-8) to 4×10(-6) mol/L and 8×10(-8) to 4×10(-6)mol/L, respectively, and the detection limits for Ponceau 4R and Amaranth were 2 and 36 nmol/L, respectively, at a signal-to-noise ratio of 3. The EGPE showed good reproducibility, stability and reusability. The proposed method was successfully applied in the detection of Ponceau 4R and Amaranth in grape juice samples.
authors.affiliation: School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
authors.forename: Meiling
authors.initials: M
authors.lastname: Wang
authors.affiliation: College of Biology and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310015, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Shentu
authors.affiliation: School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.
authors.forename: Wenchang
authors.initials: W
authors.lastname: Wang
authors.affiliation: School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China. Electronic address: zdchen.lab@gmail.com.
authors.forename: Zhidong
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000548:Amaranth Dye / Q000032:analysis*; D001391:Azo Compounds / Q000032:analysis*; D004396:Coloring Agents / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D009282:Naphthalenesulfonates / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D009282:Naphthalenesulfonates; D006108:Graphite; D000548:Amaranth Dye; C576297:ponceau 4R
keywords: Amaranth; Electrochemical method; Food analysis; Isomers; Ponceau 4R; Simultaneous determination