GC-MS Flashcards
How does GC-MS work?
It works in 2 parts. The Gas Chromatograph GC and the Mass Spectrometer MS. The GC separates the sample into its individual components and the MS detects those components and creates a spectrum that we then compare to a known reference material
What does the GC-MS instrument look like?
It looks like a box with 2 parts. It also has a needle that injects samples into the first box
How do you know your instrument was working properly the day you ran the sample?
We have 2 checks that run daily and before use we verify that those checks were performed and passed.
How do you know your sample of the instrument wasn’t contaminated?
We run a blank that we prepare with the sample before every sample to ensure that nothing is in the instrument before the sample is ran
What is retention time?
It is the amount of time that the substance spends in the GC
Does the GC-MS only test for specific substances?
No the GC-MS tests for a wide variety of substances by separating samples into its individual parts and then the MS detects those separate parts
What types of quality controls are used for GC-MS?
We have daily, weekly, and biannual maintenances that need to be performed. All samples must have a blank ran before the sample to ensure no carryover and we require 2 positive samplings to identify a substance.
What is carryover?
Carryover is when a previous sample is still in the column and enters into the next sample
How do you know that there wasn’t carryover from a previous sample?
We run a blank before every sample and look for any peaks that could indicate carryover from a previous sample. There was no carryover in the blank before this sample was analyzed which tells me that the sample I reported was not carryover. We also require 2 positive samplings to identify a sample
