Chromatographic method - Iso 17025 accreditation - Water Matrixes

Hello all!

Our laboratory here in Brazil is passing through an Iso 17025 accreditation, and i’m responsible for validating gas chromatographic methods.

We analyze water, all types of it : purified, underground, treated, etc…
I’m basing our method on EPA methods, such like 8260C.:slight_smile:
The principal analysis is volatile organic compounds with GC/MS and Head-space

My doubt: When i’ll quantify after the analysis, i’ll use my primary curve ( I’ve made a calibration curve adding the standards into purified and clean water ). So, do i have to make a calibration curve for each matrix ( different types of water)???:rolleyes:

Another specific question: When i’m using the surrogates and istd’s… I’ll have to make a calibration curve for them? and then spike to the standards to calculate the recovery right? But, as far as i know, surrogates have to be applied after the sample preparation and before the analysis ( is that correct? ), so… what happens if i have an auto-sampler??? :mad:

Thanks to everybody!