delta-7-stigmastenol standard

[Zeta]

Hi!
I´m looking for delta-7-stigmastenol standard because I´ve had some problems with the quantification of this sterol.
If someone is working in this analysis and knows if there is a comercial standard I´d like to know the supplier.

Thanks

[JGK]

The lab I manage routinely does Sterol and Tocopherol profile analyses.

We have sourced standards for Stigmasterol, beta-sitosterol, campesterol, ergosterol (provitamin D2), brassicasterol but not delta-7-stigmasterol and delta-7-avenasterol,

[Arek]

Hi,
The methods of sterol analysis known to me, assume response factors to be equal to unity, so one don't have to establish individual calibration curves and no sterol standards are needed (except IS). All that is needed is retention times of sterols and lack of interferences. This approach is quite accurate (I checked RF of stigmasterol and sitosterol and they were very close to 1). For retention time of d7-stigmasterol use oils known to have high levels of this compound, check literature data

[HW Mueller]

Arek, are you assuming that Zeta`s problems with quantitation are imagined?

[Arek]

I just suggest very simple solution stated in this topic. Maybe it will help

[AICMM]

Zeta,

Have you tried Chemservice? They synthesize many of their standards and they might be able to help you with this problem as well.

Best regards.

[MAYA]

Hi,


I know the thread is old but i am looking for same sterol standards and i can not find supplier. May be you can help me.

1. Standard solution for TLC, mix – 1.0 mg/ml cholesterol and 5.0 mg/ml betium in acetone

2. delta 7- stigmasterole, SM

3. delta 7-Avenasterol, SM

4. 24-Methylene cholesterol, SM

5. Campesterol, SM

6. delta 7-campesterol, SM

7. delta 5,23-Stigmastadienol, SM

8. Clerosterol, SM

9. delta 5-Avenasterol,SM

10. delta 2,24-Stigmastadienol, SM



Do you have idea who i can ask for this type standar materials?