| Autor: |
Yuee Wu, Kunio Nagashima, Minori Kamaya |
| Rok vydání: |
1996 |
| Předmět: |
|
| Zdroj: |
BUNSEKI KAGAKU. 45:427-429 |
| ISSN: |
0525-1931 |
| DOI: |
10.2116/bunsekikagaku.45.427 |
| Popis: |
Sample solution (10 μl) was mixed with the urease solution (5 μl), which contained 1800 units urease and 25 ml glycerin in 100 ml, in the tip of a micro pipette. After standing for 20 min, the mixture (15 μl) was dropped on the pH test paper, and the reflection absorbance (λ=570 nm) of the test paper was measured by spectrophotometry. The pH test paper was prepared by placing 40 μl of 0.1 % (w/v) Bromophenol Red {pH 5.2(yellow)pH 7.0(red)} aq. solution (pH 5.2) onto the filter paper (5B) and drying it in a desicator for 12 h. A linear relation was obtained between the concentration of urea (5120 ngN/10 μl) and the reflection absorbance of the test paper. The detection limit (S/N=3) was 2 ngN/10μl. Reproducibility tests (n=7) showed that the relative standard deviation of the response was 5.5% for 30 ngN/10μl. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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