Acrylonitrile analysis method

Question

Dear Sir/Madam, 
 I hope this message finds you well. 
 We are currently attempting to analyze acrylonitrile (m/z 53, 52, 51) using the Perkin Turbo Matrix 40 HS, 6890N GC, and 5975 MSD. 
 While we have successfully detected substances such as vinyl chloride and bromoform, we are encountering difficulties with acrylonitrile, as no peaks are appearing. 
 Even when diluting the sample in a solvent and injecting it directly, rather than using the headspace method, we are still unable to obtain satisfactory results. 
 Could this issue be related to the MSD? 
 For your reference, we are using a VF-624MS column (30 m &times; 0.32 mm &times; 1.8 &mu;m). 
 We would greatly appreciate any advice or guidance you could provide on this matter. 
 Thank you for your assistance.

paulsalverda · Accepted Answer

Column flow 3 is too high for a GCMS system. Column flow 0.8 to 1.4 ml/min is the optimal range. If you don't have the proper sized column, do you have any other columns at all? Using the proper connector you could connect two columns together to make one longer one and get the proper column flow and inlet pressure. 
 Splitless mode is not used with headspace or purge & trap systems. It is used with liquid injections. Purge flow to split vent is typically 50 to 75 ml/min at 0.8 minutes, but that time is related to the actual column flow. Then set gas saver on at 20 ml/min at 2.00 minutes. Setting purge flow to split vent at 15 ml/min at 0.00 minutes is the same as running split. 
 You are running in SIM mode, which only looks at specific ions and not all of the ions that are being created in the ion source. Please edit your method to SCAN mode, 35-500 amu, N=2, and Gain=1, save it as a new method name, and run it once. If the solvent peak is there then you need to adjust your methodology so that the solvent peak elutes completely before the peaks of interest. 
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Acrylonitrile analysis method

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