Chromatography Forum

Hello, it's my first time here.

I have a Shodex VG-50 4E HPLC column, which I want to use to measure epilactose, lactulose, and lactose. According to the manual, the mobile phase should consist of 75% acetonitrile, 20% methanol, and 5% water, with a column temperature of 40°C and a flow rate of 1 mL/min. However, I am not detecting the analytes, even when using standard samples.

I am working with a Jasco HPLC system equipped with an RI-4030 refractive index detector. What could be causing this issue?
In other laboratory with the same colum and same HPLC model it works well.

My first thought is that the detector might be the issue. You say that the same column and analytes in a different, but equivalent, system works. I would first try to purge the reference cell of the RID and see if that helps.