title: Sequential injection lab-on-valve system for the determination of the activity of peroxidase in vegetables.
abstract: Horseradish peroxidase (HRP) has been broadly used and investigated for many analytical purposes; it is an enzyme that catalyzes the reduction of hydrogen peroxide in the presence of a reducing compound. The objective of this work was to develop a methodology for the spectrophotometric determination of the activity of peroxidase in vegetable extracts using a flow method with a sequential injection lab-on-valve format. The developed system is based on the reaction between hydrogen peroxide (H(2)O(2)) and 2,2-azinobis(3-ethylbenzothiazoline-6)sulfonic acid (ABTS) catalyzed by the enzyme (HRP). The method presented a sample consumption of 15 microL per assay and a consumption of ABTS and H(2)O(2) of 24 microg and 12 microg per assay, respectively. It was also possible to monitor online the thermal inactivation of peroxidase at different temperature ranges.
authors.affiliation: CBQF/Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr Antonio Bernardino de Almeida, 4200-072 Porto, Portugal.
authors.forename: Susana S M P
authors.initials: SS
authors.lastname: Vidigal
authors.forename: Ildikó V
authors.initials: IV
authors.lastname: Tóth
authors.forename: António O S S
authors.initials: AO
authors.lastname: Rangel
mesh_terms: D001937:Brassica / Q000201:enzymology; D006861:Hydrogen Peroxide / Q000378:metabolism; D007700:Kinetics; D031223:Nasturtium / Q000201:enzymology; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism*; D027805:Phaseolus / Q000201:enzymology; D013053:Spectrophotometry; D018724:Spinacia oleracea / Q000201:enzymology; D014675:Vegetables / Q000201:enzymology*
chemical_list: D006861:Hydrogen Peroxide; D009195:Peroxidase