Failing Initial Calibration on HP 5890

[EnvChemist]

Hello people,

I run PCBs on a HP 5890 ECD GC. For the past month or so I have had to run an initial calibration on my instrument almost every other day.

It can't be contamination from my samples because I am only running MDLs on that instrument.

I completely cleaned out my injection port, put in a new liner, septum, gold seal, syringe and replaced the weldman and gas lines but still had the same problem.

Next I changed the split ratio from 5:1 to 12:1 and changed my injection volume from 1ml to 2ml, but now I can't my initial calibration to pass.

I am almost out of ideas .... how should I proceed ?

Somebody help me !!!!

Thanks..

[Rick]

Hi!
First,why do you have change or clean injector, liner, ect....?what was your problem for change this item?

[EnvChemist]

I changed the liner and cleaned out the instrument to rule out the possibility of contamination from the instrument.

[Rick]

Hi!
Your initial calibration don't pass.....why?...give your symptoms...area count, sensitivity, tailing,no or lost of peak??

[AICMM]

How old/used are your detectors? Have you considered the possibility that they may need cleaning? That is a common problem with a local
laboratory I work with. Their 5890 ECD's will show slightly elevated standing currents and not be able to hold calibration.