Enzymatic sensor coupled to a flow-injection analysis system for the determination of salicylate

✍ Scribed by M. Neumayr; G. Sontag; F. Pittner

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 514 KB
• Volume: 305
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)00501-c

✦ Synopsis

A quick and reliable enzymatic method for the direct determination of salicylate in pharmaceuticals after appropriate dilution is described. The enzyme salicylate hydroxylase was attached directly onto a platinum working electrode of a wall-jet cell coupled with a flow-injection analysis system. Therefore, the platinum electrode was oxidized, silanized and derivatized with p-tetrachloroquinone, then the enzyme was covalently bound to the quinone and afterwards crosslinked with glutardialdehyde. The enzymatic conversion of salicylate to the electrochemically detectable catechol is about 25%. It can mainly be influenced by the amount of coenzyme added and by the flow velocity. The response of the biosensor is linearly proportional to the concentration of salicylate between 7.25 PM and 4.35 mM. A high sample throughput (60 hh'l is possible, and the biosensor is stable for at least three months. The assayed samples yielded relative standard deviations between 1.7 and 4.3% and recoveries between 83 and 104%.