Akta purifier hplc system

Akta Purifier HPLC system (Amersham Pharmacia Biotech, Piscataway, NJ, USA) and reverse phase column (Waters Spherisorb ODS 2-C18, 250 mm × 4.6 mm, 5 µm, Milford, MA, USA) were employed for quantitative analysis of reactants and products. The reaction mixture was fifteen times diluted with methanol and injected in portions of 10 μL. As mobile phase Methanol/H 2 O/H 3 PO 4 , 70-100/30-0/0.1 % (v/v), was used with a flow rate of 1 mL min -1 . Mobile phases were 70 % methanol for the determination of ascorbyl acetate and caproate, 90 % for caprate and myristate, and 100 % for stearate and oleate. Retention time of vitamin C was similar, regardless of eluent composition, and it was in range 2.3-2.5 minutes.
Retention times of ester derivatives and corresponding acids were as follows: acetate and acetic acid -3.62 and 4.65, caproate and caproic acid -3.95 and 4.86, caprate and capric acid -3.84 and 4.75, myristate and myristic acid -3.94 and 4.79, stearate and stearic acid -6.13 and 7.88, and oleate and oleic acid -3.53 and 4.54. UV detection of products and vitamin C was done at 235 nm, while fatty acids were detected at 210 nm.