Why use smaller ID Columns and smaller Flow Rates in LC?

Modern biological research often produces large sample sets that need to be analyzed in a minimal amount of time. Additionally, target compound concentrations in these samples may be very low. When sample concentrations and volumes are small, injection onto conventional internal diameter (ID) HPLC columns of 2.1 mm, and even narrow bore 1 mm ID, often reveals a lack of sufficient detection sensitivity. This is especially the case for ESI LC-MS where the inlet system is concentration dependent. Continue reading Why use smaller ID Columns and smaller Flow Rates in LC?