An ÄKTAmicro™ chromatograph(GEHealthCare,Buckingham-
shire,England)equippedwithtwoP-900pumps,anINV-907man-
ual injectora100 μL loop,aUV–visibledetector(UV-900)andUni-
corn5.11software(GEHealthCare, Buckinghamshire,England)for
data processingwereemployed.