Cortisol
| Analyt: | Cortisol |
| Matrix: | Serum |
| Measuring Method: | GC-ID/MS |
| Standard: | Cortisol NIST 921 |
| Internal Standard: | Cortisol-d₂ |
| Sample Processing: | Samples are spiked gravimetrically with internal standard and equilibrated. They are made alkaline with aqueous KOH and extracted into dichloromethane. A "pre-clean" step is made with a Sephadex LH-20 column. Derivatisation is with acetone-HFBA and subsequent extraction into cyclohexane. |
| Measurement: | Measurement at m/z 489 and m/z 491 |