A screening method for trace mercury analysis using flow injection with urease inhibition and fluorescence detection

✍ Scribed by D. Narinesingh; R. Mungal; T.T. Ngo

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 493 KB
• Volume: 292
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)00032-8

✦ Synopsis

A flow-injection screening method based on urease inhibition is described for the determination of trace amounts of the heavy metal ions, mercury and silver. The method is based on the inhibitory effect that these ions have on the enzyme urease which catalyzes the conversion of urea to carbon dioxide and ammonia. The liberated ammonia is monitored fluorimetrically using o-phthalaldehyde as the fluorophore (A, = 340 nm, A, = 455 nm). A detection limit of 2 ppb can be achieved. Comparison of this flow injection method with that of the standard cold vapour atomic absorption technique for mercury determination gave a standard deviation of 0.02 and a coefficient of variation of 2%. Also one-way ANOVA shows no significant difference between these two methods.