title: Application of lactate amperometric sol-gel biosensor to sequential injection determination of L-lactate.
abstract: This work describes the construction and evaluation of lactate sol-gel biosensors to accomplish the determination of lactate in pharmaceutical products. Lactate oxidase was incorporated in a porous sol-gel film placed onto a platinum-based electrode. Acid and basic catalysis were assessed. When coupled to a sequential injection system (SIA) the biosensor, based on (3-aminopropyl)trimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, deionised water, polyethylene glycol 6000 and acid catalyst, presented a range of linearity of 5x10(-5) to 5x10(-3)M. The analytical usefulness of the developed biosensor was evaluated through analysis of commercial pharmaceutical products containing lactate with a sampling rate of 40 samples h(-1). The enzyme remained active for at least 30 days, enabling about 700 determinations without sensitivity decrease.
authors.affiliation: REQUIMTE, Departamento de Química-Física, Faculdade de Farmácia, Universidade do Porto, Rua Anibal Cunha, 164, 4099-030 Porto, Portugal.
authors.forename: Sofia Piedade
authors.initials: SP
authors.lastname: Gomes
authors.forename: Martina
authors.initials: M
authors.lastname: Odlozilíková
authors.forename: M Gabriela
authors.initials: MG
authors.lastname: Almeida
authors.forename: Alberto N
authors.initials: AN
authors.lastname: Araújo
authors.forename: Cristina M C M
authors.initials: CM
authors.lastname: Couto
authors.forename: M Conceição B S M
authors.initials: MC
authors.lastname: Montenegro
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000032:analysis* / Q000737:chemistry; D005782:Gels; D007700:Kinetics; D019344:Lactic Acid / Q000032:analysis* / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000032:analysis / Q000737:chemistry; D044367:Phase Transition
chemical_list: D004800:Enzymes, Immobilized; D005782:Gels; D004364:Pharmaceutical Preparations; D019344:Lactic Acid