The HPLC system consisted of a 655 A-11 pump, 655 A-71 proportioning value, 655 A-22 variable
wavelength UV monitor, 655-s processor, all of Merck Hitachi and a Readyne 7161 sample injection valve
with a 20-pl sampling loop. The separation was achieved on a 25 cm x 4,6 mmid column prepacked with
10 ~m partisil 10 pac purchased from Alltech Assoc.