## Abstract A simple and rapid reversed phase highโperformance liquid chromatographic method for separation and determination of elemental sulfur in technical thiophanateโmethyl using a reversedโphase C~18~ column and methanolโwaterโtetrahydrofuran (90ย :ย 8ย :ย 2 __v/v/v__) as eluent with UV detection
High-performance liquid chromatography determination of enzyme activities in the presence of small amounts of product
โ Scribed by Mario Pace; Pierluigi Mauri; Piergiorgio Pietta; Dario Agnellini
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- English
- Weight
- 282 KB
- Volume
- 176
- Category
- Article
- ISSN
- 0003-2697
No coin nor oath required. For personal study only.
โฆ Synopsis
Enzymes can be assayed by HPLC by calculating the amount of substrate(s) left over, or product formed, through the peak area ratios with a suitable internal standard. However, sometimes the substrates used are contaminated with small amounts of products and this can lead to errors in the determination of the enzyme activity. A method for a HPLC test of such enzymes, which prevents eventual errors, uses the ratio substrate/product at time zero as internal standard and the kinetics can be followed with the aid of a simple mathematical equation. This approach was applied to the determination of the activities of papain, urokinase, NAD glycohydrolase, and pyruvate kinase samples and it was compared with the data obtained by the internal standard method, giving reproducible results in all cases.
๐ SIMILAR VOLUMES
The cytochrome P450 enzyme geraniol 10-hydroxylase plays an important role in the biosynthesis of pharmaceutically important alkaloids in Catharanthus roseus. An HPLC assay was developed for this enzyme based on the UV detection of the product 10-hydroxygeraniol after its separation from the substra
The mean values of alpha and beta-carotene of 10 fruits and vegetables from supermarkets in Cairo and Alexandria have been determined using HPLC method, and the average vitamin A activities (in retinol equivalents) calculated. Carrots, spinach and sweet potatoes were the best sources of provitamin A