Determination of triacylglycerols of seed oil of Valeriana officinalis using a reverse-phase HPLC with two detection methods

Abstract

In the paper the method of reversed-phase HPLC with refractometric and spectrophotometric detection was used for determination of Valeriana officinalis seed oil. The assignment of peaks was made using the flax seed oil in the case of refractometric detection and Momordica charantia seed oil in the case of spectrophotometric detection based on incremental approach and the main oil acid was found to be α-eleostearic, while the oil contains only about 4% of triacylglycerols (TAG), without radicals of α-eleostearic acid. The peculiarities of triacylglycerol (TAG) retention parameters calculation in the case of refractometric detections were discussed in terms of column overloading. Mole fraction of seed oil TAGs were calculated upon peak areas (corrected areas in the case of refractometric detection): main one TAG – α-eleostearate-dilinoleate (55.0/58.1 mole %), di-α-eleostearic-linoleate (16.6 / 14.7 mole %), α-eleostearate-linoleate-oleate (11.1 / 11.3 mole %), α-eleostearate-linoleate-palmitate (7.1 / 7.4 mole %) (the data are given for refractometric and spectrophotometric methods of detection, respectively). Discrepancy between the data may be due to the presence in the oil isomeric triene acids. Fatty acid composition, calculated by both methods are close to each other: triene acid 39.2 (39.3) %, linoleic – 51.1 (50.6) %, oleic 5.9 (6.0) %, palmitic – 2.4 (3.3) % and stearic 1.4 (0.9) %.