title: Simple flow injection for determination of sulfite by amperometric detection using glassy carbon electrode modified with carbon nanotubes-PDDA-gold nanoparticles.
abstract: A new approach is presented for sensitive and selective measurement of sulfite (SO3(2-)) in beverages based on a simple flow injection system with amperometric detection. In this work, the sulfite sensor was a glassy carbon electrode modified with multiwall carbon nanotubes-poly(diallyldimethylammonium chloride)-gold nanoparticles composites (CNTs-PDDA-AuNPs/GC). Electrochemical oxidation of sulfite with this electrode was first studied in 0.1M phosphate buffer (pH 7.0) using cyclic voltammetry. The results indicated that the CNTs-PDDA-AuNPs/GC electrode possesses electrocatalytic activity for the oxidation of sulfite with high sensitivity and selectivity. Sulfite was quantified using amperometric measurement with the new sensor at +0.4V vs Ag/AgCl in conjunction with flow injection. The linear working range for the quantitation of sulfite was 2-200 mg L(-1) (r(2)=0.998) with a detection limit of 0.03 mg L(-1) (3σ of blank) and an estimated precision of 1.5%.The proposed method was successfully applied to the determination of sulfite in fruit juices and wines with a sample throughput of 23 samples per hour.
authors.affiliation: Department of Chemistry and Center of Excellent for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand; Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Bangkok 10400, Thailand. Electronic address: scmaliam@ubu.ac.th.
authors.forename: Maliwan
authors.initials: M
authors.lastname: Amatatongchai
authors.affiliation: Department of Chemistry and Center of Excellent for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand.
authors.forename: Wongduan
authors.initials: W
authors.lastname: Sroysee
authors.affiliation: Department of Chemistry and Center of Excellent for Innovation in Chemistry, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand.
authors.forename: Sanoe
authors.initials: S
authors.lastname: Chairam
authors.affiliation: Flow Innovation-Research for Science and Technology Laboratories (FIRST Labs), Bangkok 10400, Thailand; Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
authors.forename: Duangjai
authors.initials: D
authors.lastname: Nacapricha
mesh_terms: D001628:Beverages / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D017022:Flow Injection Analysis / Q000295:instrumentation; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013447:Sulfites / Q000032:analysis*; D014920:Wine / Q000032:analysis
chemical_list: D037742:Nanotubes, Carbon; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D013447:Sulfites; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D002244:Carbon; D006046:Gold
keywords: Amperometry; AuNPs; CNTs; Flow injection analysis; PDDA; Sulfite