Determination of phytosterols in Oryza sativa L. cultivars by liquid chromatography atmospheric chemical ionization time-of-flight mass spectrometer (LC-APCI-TOF-MS) coupled with a modified QuEChERS method

Development of analytical methods for the determination of phytosterols in whole grains is one of growing interests due to their clinical and nutritional functions in human. In this study, we examined simultaneous determination of β-sitosterol, stigmasterol and campesterol in Korean rice cultivars by liquid chromatography atmospheric chemical ionization time-of-flight mass spectrometer (LC-APCI-TOF-MS). The hulled rice samples were extracted using a modified QuEChERS and analyzed by LC-APCI-TOF-MS. The method was validated by low limit of detection (LOD) and limit of quantification (LOQ) values and high recovery values with low relative standard deviation (RSD). The highest concentration of sitosterol was detected in Hwasung and Undu rice cultivars, exhibiting approximately 195.5 and 191.7 mg/Kg, respectively. Stigmasterol and campesterol were detected at the highest level in Hwasung rice cultivar, giving the concentrations of approximately 70.0 and 53.9 mg/Kg, respectively. Sitosterol was determined to be a main phytosterol detected in the rice samples. Our data demonstrated that LC/APCI-TOF-MS coupled with QuEChERS method can be used as a simple tool for the determination of phytosterols in rice samples.