Transferring Conventional LC Methods To Ultra Fast Liquid Chromatography

To develop an ultra-fast LC method for the determination of seven barbiturates from an existing LC method.

Methods
The existing method utilized a 23-minute run time to separate seven barbiturate compounds with a reversed-phase gradient using a Shim-pack VP-ODS column (4.6 x 150 mm, 4.6 um) on a conventional LC system. A UFLC method transfer program was utilized to provide suggested conditions for the ultra-fast analysis. Two ultra-fast analyses were requested from the program, one that maintained 99% resolution of the existing method, and a second that focused on reducing analysis time with 50% of the original resolution. The suggested methods were run on a UFLC system with Shim-pack XR-ODS columns (3.0 x 75 mm, 2.2 um and 3.0 x 30 mm, 2.2 um), respectively.

Results
A 4.9-minute run time was suggested for the high-resolution analysis. Resolution ranged from 89 to 103% of the original separation, with a mean value of 94%. A 0.8-minute run time was suggested for the high-speed method. Resolution ranged from 44 to 60% of the original separation, with a mean value of 50%.