Development of a GC-MS/SIM method for the determination of phytosteryl esters

A gas chromatography-mass spectrometry (GC-MS) method with selected ion monitoring (SIM) was developed and validated for identification and quantitative analysis of three phytosteryl esters, i.e., campesteryl oletate, stigmasteryl oletate and β-sitosteryl oletate. The method is simple and efficient and achieved good separation of the three phytosteryl esters in 10 min without saponification and liquid-liquid extraction. A calibration curve for the three phytosteryl esters had a correlation coefficient (R²) better than 0.993. Detection limits were 0.42 mg/mL for campesteryl oletate, 0.32 mg/mL for stigmasteryl oletate and 0.80 mg/mL for β-sitosteryl oletate. The relative standard deviations (RSD) were within 5.47% for precision and stability for three edible oil samples. Recoveries were from 89.85% to 97.65% for each of the phytosteryl esters. These results suggest that the method can be used to identify and quantify the phytosteryl esters in oil samples.