𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Determination of urease activity by flow-injection analysis using an ammonium-selective optrode as the detector

✍ Scribed by Hong Li; Otto S. Wolfbeis

Publisher
Elsevier Science
Year
1993
Tongue
English
Weight
450 KB
Volume
276
Category
Article
ISSN
0003-2670

No coin nor oath required. For personal study only.

✦ Synopsis

Urease activity is determined by a combination of flow-injection analysis with optical sensor detection. Enzymatic hydrolysis of urea at pH 7.14 yields ammonium ions, which are determined using a fully reversible optical fibre ammonia sensor. Urea is contained in a buffered carrier stream into which urease samples of various activities are injected. The ammonium ions are measured fluorimetrically using a sensor membrane based on an ion-exchange sensing scheme using nonactin as the ion carrier. The amount of ammonium ion formed is a direct indication of the enzyme activity. The system linearly correlates with urease activity in the range l-30 U ml-', the dynamic range being between 0.3 and 30 U ml-'. The method provides an easy and rapid assay for urease activity.

📜 SIMILAR VOLUMES

Determination of β-amylase activity by a
Determination of β-amylase activity by a fluorimetric 2-p-toluidinylnaphthalene-6-sulfonate flow-injection analysis (2,6-TNS–FIA) method, using amylose and amylopectin as substrates
✍ Natalia Batlle; José V. Carbonell; José M. Sendra 📂 Article 📅 2000 🏛 John Wiley and Sons 🌐 English ⚖ 125 KB 👁 1 views

2-p-Toluidinylnaphthalene-6-sulfonate (2,6-TNS) is a compound which is barely fluorescent in pure water but whose fluorescence can be strongly enhanced if the environment becomes hydrophobic, i.e. by the addition of suitable substrates such as proteins or 1,4-␣-Dglucans. The enhancement of fluoresce