Sterols from Peanut Butter on ZB-5MS

Sample Preparation Details

Part No:8B-S001-JCH
Solid Phase Extraction (SPE) procedure:Note: The solvent volumes shown below are for a 1 g bed mass. The solvent volumes will need to be adjusted for a smaller or larger bed mass.
Load:Shake and reflux 0.73 g peanut butter in 20 ml 0.5 M KOH in ethanol for 20 min at 77 °C. Cool down then add 10 ml 0.22 mg/ml betulin (istd) in chloroform and shake for 5 min. When settle, piptte and filter 3ml aliquot through BD 10 ml needless syringe screw to a Phenex 30 mm 0.45 um teflon filter and collect filtrate in a 4 ml screw cap sample vial.
Set up and condition a Strata C 18-E SPE (55 um, 70 A) on manifold, and manifold
to a vacuum pump, SPE cartridge bottom end directed into a 1/125 mm culture tube, with 5 ml methanol and 5 ml chloroform. Replaced conditioning material with a new and labeled culture tube. Pipette 1 ml filtrate onto miniscuos chloroform-SPE sorbent and elute sterolst with 15 ml 5 % methanol chloroform. Dry elutant with nitrogen and concentrate to 1 ml then pipette 200 ul aliquot to a 500 ul insert sample vial and dry it with nitrogen. Reconstitute sterols with 100 ul pyridine and derivatize with 100 ul BSTFA:TMCS; 99:1. Warm up at 70 °C for 20 min and inject.
Final Prep and Analysis: Initial Samole Unit: gram Inject: 0.5 µL on GC / Flame Ionization (FID) @ / (320 °C)


Name Spiked
Log P pKa % Rec %RSC (n=0)
1 Campesterol
2 Stigmasterol
3 b-Sitosterol
4 Betulin

Application Detail (App ID: 16513)

Part No:7HG-G010-11
Phase:5% Phenyl-Arylene 95% Dimethylpolysiloxane
Dimensions:30 meters x 0.25 mm x 0.25 µm
Oven Profile:225 °C to 330 °C @ 15 °C/min for 2 min.
Carrier Gas:Constant Flow Helium, 2.5 mL/min
Injection:Splitless :1 0.5 µL @ 320°C
Detection: Flame Ionization (FID) (320°C)
Note:Sample prep- Saponification, Solid Phase Extraction, and Derivatization.

Analyte Details

Analyte Detail not available