High HPLC column back pressure

[Mmoneng]

Hi, everybody. I am using YMC Pro-Pack C18 column, 2.1 mmx150mm, 5um, for LC-MS work. I am currently experiencing a serious problem and in need of help from the experts in this field. I vary the flow rate from 0.2ml/min to 0.8ml/min and set the max pres to 3000psi but the system insists on giving me the message, "Maximum Pressure Exceeded". How can I solve this problem and can anyone give me an SOP of how to wash/clean this column?

Thank u
Mmoneng

[MG]

0.8 mL/min is rather high flow rate for this column, equivalent to running a 4.6x150mm at 3.8 mL/min. It is reasonable to expect that your pressure would be higher than 3000 psi. Depending on your mobile phase, you might not even be able to run at this flow rate without exceeding the maximum limits of your pump or tubing. Either raise your pressure limit up to the maximum (~ 5000 psi), or use a lower flow rate.