It is designed for ion exchange separation followed by postcolumn ninhydrin derivatization. This instrument uses Beckman's sodium based 4 mm x 12 cm High Performance column and sodium citrate buffers. A three step pH and three step temperature gradient are used in the normal run program. Beckman's System Gold version 4.03 is the data system that was used. This standard calibration procedure is performed each time unknown samples are to be analyzed.
Instrument maintenance is performed at various intervals.
Maintenance performed before every run includes checking the pressure, column temperature, and bubble traps. Duplicates of each sample are always performed. To perform the standard analysis on the ABRF sample, the volume equivalent of 5 ug was transferred to an ampule and evaporated in a Savant Speed Vac system. The sample was frozen in liquid nitrogen and evacuated to approximately 100 mtorr. The valve was then closed and the sample was thawed to release any additional oxygen that may be dissolved in the sample.