Separation and identification of tocotrienol isomers by HPLC-MS and HPLC-NMR coupling

A crude palm-oil extract rich in vitamin E homologues was investigated by H PLC-MS and HPLC-NMR coupling. For mass spectrometry a newly introduced ioni zation technique called Coordination Ion Spray (CIS) was used. Through the addition of silver ions to the HPLC eluent, the ionization process of nonpo lar substances is facilitated. Chromatography and all coupling experiments were conducted on a C-30 column which exhibited an extraordinary shape sele ctivity and overwhelming sample-loading capability. Experiments were perfor med with pure methanol as an eluent which proved to be ideal for NMR spectr oscopy as well. as mass spectrometry, All necessary information for unambig uous structural assignment was collected within 45 min of the LC-NMR experi ment and 15 min of the LC-MS experiment. Six compounds were identified, i.e ., alpha-, beta-, gamma-, and delta-tocotrienol, alpha-tocoenol, and alpha- tocopherol.