Chromatography Forum

I use manual sampler in my agilent HPLC 1100. I am facing a problem with this from the last week.
As I load the sample and turned it down the programme does not start. Pumps are alright and a change I made in concentrations of solvents is responded by the pump. The problem is only in running the programme.
Can anyone help me over this?

By manual sampler do you mean you are using a manual injection valve? The system is probably waiting for the autosampler to tell it that the injection has been made. If you have a manual valve then it should have a contact closure switch which needs to be attached to the pump to tell it that the sample has been injected.

thnx for ur reply.
yes it has an injection valve which is attached to a green tubing that goes to the pump which triggers the response when smple is injected. Can you tell me how to know if there is fault in this contact and how I can fix it myself (If it is possible to fix it without the help of engineer).
Waiting for ur reply.

Connect an RS 232 cable to the 'remote out' of the pump. Try an making an injection and chemstation will not start but will wait for a signal. At the other end of the cable try touching each pin to ground, one at a time. Consult your chemstation manual for which one is ground. Touching the correct pin to ground should trigger the HPLC to start. Now you need to connect the wires from the valve to this pin. If you don't have a switch on the valve you will need one. You can buy a simple contact closure switch at a radio shack if you don't have one. You will need to have the valve handle press the contact closure switch and also hook the wires to ground and the pin of the rs232 that makes the run start. Should work. Good luck!