Two serial connected analytical columns, a Waters Spherisorb ODS2 PEEK lined (Alltech, cat. no. 8161),100×4.6mm (5m particle size, 80Å pore diameter, 12% carbonload) connected to a reversed phase Vydac (cat. no. 201TP54) containing silica polymerically modified with C18, 250×4.6mm(5m particle size, 300Å pore diameter, 8% carbon load) were used