I'm new to the techniques of HPLC and looking for some helpful advice! I'm interested in developing a method for purifying a cyanogenic glycoside. Up until now the glycoside has been running out at around 7 minutes on a 5u C18 column in a mobile phase of 98:2 - Water + 0.1% H3PO4 : 80% MeCN + 0.1% H3PO4. I have poor peak separation and want to improve this as well as extending the column retention time for the glycoside. Does anyone have any advice on potential new methods?