Thanks for the response,
No sir, i got the new instrument so there may not be any maintenance problem.
My problem i think is the injection method or Integration method.
Is there any auto integration by software in Ezchrome?
Is there any trick in injection methods to minimize RSD?
1) The fact that the new tool - does not mean there are no problems.
In addition, persistence of some supplies is negligible. Septa maintains no more than 1000 injections, and recommend it to change even at one-hundredth, not waiting for when it gets dirty or her needle pierce through-hole
2) What is injection method ? Liquid handmake (RSD about 10% to 1 mkl), Liquid autosampler (RSD about 1,5% to 1 mkl) , Automatically headspace (RSD about 2% from unpolar low boiling liquid in water , to 10% from vary polar high boiling liquide in water) , handmake headspace (RSD more 10%).
If you use Automatical static Headspace as 1888
a) One flack - only one injection.
b) Liqud volume in headspace flack should be the same
c) Heat time need more 15 min.
d) T in transfer line and loop should be > boil temperature of probe analising components
Toluene boil in 110C - transfer line need 120 C
I think that all this is done, and here the problem can not be.
3) What problem in Integration ?I don,t job by Ezchrome , but think that all this is done, and here the problem can not be also. Peak of methanol and toluene full separate , and in good chromatography metod - vary simmetry and have small tailing factor (0.9-1.5).
Problem may be only in vary small concentration , around limit of sencivity - the noise peak (jump) summed whith peak . But in subtancies limit of sencivity isnt critical - its 0,1-1 ppm on methanol and about 0.5 ppm on toluene (FID , SP 1:10). This is less than the requirements of WHO is a thousand times, so even a 10% deviation in this case is irrelevant.
(!) May be problem in
calculate if you do not take into account the true mass of the samples.
In this case, the error in the hitch is summed with the other errors.
For electrified substances attempt
to take a sample of the eye usually leads to very large variant of mass.
The same problem may be, if
you do an analysis of packaged products, without weighing it.
A well-tuned machine by pouring into bottles has precision of about 5%, well-tuned machine for pressing pellets/ tablets - about 3%. On the production line (in farmaceutical factory) there may be several, and each mistakes.In addition, the production always acts the human factor - the working-apparatchik may be inexperienced (not to sleep, go to the binge) and the proper setup will not have to say.