Determinação indireta de N-acetil-L-cisteína por injeção em fluxo empregando Ce(IV) e ferroína

Autor: Vieira Heberth Juliano, Fatibello-Filho Orlando
Jazyk: English<br />Spanish; Castilian<br />Portuguese
Rok vydání: 2005
Předmět:
Zdroj: Química Nova, Vol 28, Iss 5, Pp 797-800 (2005)
Druh dokumentu: article
ISSN: 0100-4042
1678-7064
Popis: An indirect flow injection spectrophotometric procedure is proposed for the determination of N-acetyl-L-cysteine in pharmaceutical formulations. In this system, ferroin ([Fe(II)-(fen)2]2+) in excess, with a strong absorption at 500 nm, is oxidized by cerium(IV) yielding cerium(III) and [Fe(III)-(fen)2]3+ (colorless), thus producing a baseline. When N-acetyl-L-cysteine solution is introduced into the flow injection system, it reacts with cerium(IV) increasing the analytical signal in proportion to the drug concentration. Under optimal experimental conditions, the linearity of the analytical curve for N-acetyl-L-cysteine ranged from 6.5x10-6 to 1.3x10-4 mol L-1. The detection limit was 5.0x10-6 mol L-1and recoveries between 98.0 and 106% were obtained. The sampling frequency was 60 determinations per hour and the RSD was smaller than 1.4% for 2.2x10-5 mol L-1 N-acetyl-L-cysteine.
Databáze: Directory of Open Access Journals