UHPLC Determination of Nadolol in Feed with Separation by Hydrophilic Chromatographic Column

The hydrophilic chromatographic column, Waters AcQuity BEH Hilic column was used in UHPLC determination of nadolol in feed. The sample was extracted ultrasonically twice with 15, 10 mL of 1% (φ) methanol. The supernatants were combined. An aliquot of 5 mL was taken and purified by passing through MCX SPE micro-column. The column was eluted with 5 mL of mixture of 5% (φ) CH3OH and NH3 (aq.). The eluate was evaporated to dryness by N2-blowing at 40 ℃, and the residue was taken up with 1 mL of the mobile phase which is a mixture of acetonitrile, 0.5% formic acid solution, and water, mixed in the ratio of 10 to 15 to 75. An aliquot of 1.0 μL was introduced and analyzed by UHPLC. Satisfactory separation of nadolol was attained by using the Hilic column and the above mentioned mixture as mobile phase. Linear relationship between values of peak area and mass concentration of nadolol was kept in the range of 0.01-20 mg·L-1. Lower limit of determination (10S/N) found for the method was 0.01 mg·kg-1. Values of recovery found by standard addition method were ranged from 78.5% to 95.0%, with values of RSD′s (n=5) less than 8%.