Pulsed Splitless injection of FPD
Posted: Tue Aug 01, 2023 6:26 pm
I have noticed a coworkers method and see something that does not make sense to me. He inherited the method from previous employees. Using a 30M x 0.25mm x 0.25uF column the head pressure at idle is 44 PSI. The method has a setting for pulse pressure of 25 PSI and pulse time of 0.3 minutes. The purge time is set for 0.75 minutes. After the pulse time the method goes back up to 44 PSI head pressure.
I thought the point of pulse was to increase the pressure at injection time for a very short time to keep the sample from causing a back flash. This method does the exact opposite by lowering pressure for the splitless injection - and raising it for the remainder of the method. If there is any reason for doing this pressure drop on injection?
Thanks.
I thought the point of pulse was to increase the pressure at injection time for a very short time to keep the sample from causing a back flash. This method does the exact opposite by lowering pressure for the splitless injection - and raising it for the remainder of the method. If there is any reason for doing this pressure drop on injection?
Thanks.