Chromatography Forum

Hi Folks
I've got a real old Shimadzu SIL-10A that was working fine and then during a run the retention times started shifting to later and the response went up ~30% and the injection port leaks when it is not injection
I just replaced the entire injection port/rinse port/drain assembly with another used one that was working and that didn't help..I just swapped the bypass tube and that didn't help...I might try pulling the drain capillary out of the drain tube and seeing if that helps...flow is .5 ml/min 70:30 ACN:Water, pressure has not changed at ~120 pascals which is normal for this system....no other leaks...so is this caused by bad stator/rotor or?
If I set the injector to 8ul instead of 10 the response is good so what causes an increase in response?
We swapped this unit in for a broken 10ADVP which needs valves rebuilt so are kinda stuck!
Appreciate any help!
Thanks
Eric

Normal injector maintenance is needed. Replace the injector rotary valve seal(s) and clean and inspect the remaining parts for wear, damage or corrosion (replace as needed).
Consider having the entire HPLC properly serviced before use. You will save time and money by having the system serviced before use.