Academic CentreSterol research methods in biological matrices under gas chromatography conditions mostly differ by various sample preparation techniques. A particularly labour-intensive process is the extraction of sterols from oils of vegetable origin, given their low content. The main task is to separate the sterols from the base matrix, which mainly consists of fatty acid triglycerides. Traditionally, saponification is performed for this purpose in an alkaline alcohol solution, thus separating the unsaponifiable components – sterols, macromolecular alcohols, hydrocarbons and others. Solid phase extraction is relatively efficient, saving time and reagents. In some cases, direct oil injection into the chromatographic system may be used. Simplified sample preparation allows the value of the obtained result to be wider in range. However, sometimes, depending on the nature of the sample or the result to be obtained, such a step is necessary.
- Preparation of the obtained samples for analysis
- Performing chemical analyses using the required methods
- Comparison of the obtained results with the maximum permissible concentration or indicative permissible concentration
- Preparation of results and assessment of the degree of hazard of the identified substances
ISO 12228-2:2014 Determination of individual and total sterol contents. Gas chromatographic method.
Clarus gas chromatograph with mass selective detector (GC/MS) and automatic sample introduction system.
| Compound | CAS Nr. | Compound | CAS Nr. |
|---|---|---|---|
| Cholesterol | 57-88-5 | Sitosterol | 83-46-5 |
| Cholestanol | 80-97-7 | Sitostanol | 1058-61-3 |
| Brassicasterol | 474-67-9 | ∆5-Avenasterol | 18472-36-1 |
| 24-Methylenecholesterol | − | ∆5,24-Stigmastadienol | − |
| Campesterol | 474-62-4 | ∆7-Stigmastanol | − |
| Campestanol | 476-60-2 | ∆7-Avenasterol | 23290-26-8 |
| Stigmasterol | 83-48-7 | Erythrodiol | 545-48-2 |
| ∆7-Campesterol | − | Uvaol | 545-46-0 |
| Clerosterol | 2364-23-0 | Betulin | 473-98-3 |