TQ – colombia

Record: 310

Category: Column Problem
Product:
Sample:

Question
This customer is having some problems with the column , he washed the column but the pressure is still very high , the flow rate he is working is around 0,5ml/min with a Pressure of 3000PSI, but the flow rate he needs to work should be around at 1,5ml/min for which he can’t work with the column , do you think this is the problem , can this column work under this flow rate for retention purposes ?

Sample : morphine Hydrochloride
Column :C8 de 4.6 X 250 mm
Móvil phase :0,74g hexanosulfonato sodium in 720ml of wáter and 280ml of methanol, 10ml of acetic acid .
pH =2,85

Answer
The maximum pressure for silica C8 column is 2800 PSI and the maximum flow is 1.0 mL/min.
The customer could increase the temperature (up to ~50oC) and may increase the flow rate without going over the maximum pressure.
However, I would recommend using the column at back pressure <1500 PSI. Seems like the solubility of morphine hydrochloride in water is not great. What we can assume is that it has been crystalized inside the column. What cleaning method the customer used is unknown, but if this was not done, I would recommend cleaning the column with followings: Reverse the flow. Heat the column at 50 oC. Use flow rate ~0.2 mL/min. Use hot water (~50 oC) to clean the column.     Additional Comments
follow up on 7/22

Download or Print PDF