Bent manual GC needle

[ashrestha]

Hi friends,

I have 2 questions:

First is :

I am using SRI GC. I manually inject my samples to GC. Recently the syringe I have been using got bent while pushing it in one of the vials.
I am concerned that it might create some error in my data. Could anyone please tell me if its gonna effect my data ?

Second Question is:
I am doing a time series analysis. I analyse for different gas concentration on interval of 24 hours. So how often do I need to re calibrate my machine ?


I will appreciate suggestions

Thanks
Anil

[Consumer Products Guy]

Hi friends,
First is :

I am using SRI GC. I manually inject my samples to GC. Recently the syringe I have been using got bent while pushing it in one of the vials.
I am concerned that it might create some error in my data. Could anyone please tell me if its gonna effect my data ?

Do you only have 1 syringe ????? If so, that's sad. As to error, are your repeat injections reproducible? That should answer your question.

One should support the needle to minimize chance of bending.

[Don_Hilton]

How often to recalibrate? How much data are you willing to lose when you find out the instrument is out of calibration?

You need to run a chek standard - at least - every now and again to be sure your instrument is reading correctly. If I do not calibrate the method often, I like to at least run a high, low,and meedium level standard as check samples periodically to be sure the instrument is not drifting in sensitivity and is remaining linear in response. In some analyses, you can run continuing calibration standards rather than check samples. In other analyses, you have specific times when a full calibration must be run - times like after a change to the instrument or a check standard falling outside of specified tolerance.

The control of a method depends on the variability of the method and what you are going o do with the data. Data used in a project that is scoping out a possibility requires a lot less control than data being used to take an offender to court or a method used to monitor a process in which an error can result in loss of human life.

[Don_Hilton]

And on the bend in a needle - if you can pull it between your fingers and it comes failry straight, you are probably OK (run a check standard). If it has a sharp kink in it - it's done. Even if it delivers correctly, expect it to tear up the septum.