Hello,
I am doing linearity test of 1-Dodecanethiol on GC by prepping 6 standard solutions from 10 to 35 ppm in DCM (adding BSTFS as a derivatizing agent). 1-Dodecanethiol peak comes sharp initially but after few hours, it starts decreasing and meanwhile another unknown peak starts appearing, gradually. RT of first peak is 7.5 elutes at around 225C and RT of unknown peak is 8.5 min (Column oven temp profile - 30C/min, 10C/min to 35C, 1 min hold, 40C/min to 200C, 15C/min to 350C) . In my first trial, second peak started appearing after 10 hours of making standards and in my second trial, it started appearing after 5 hours of making standards. Do anyone have experience of working with 1-Dodecanethiol? What should I do to get 0.99 R-square value in the linearity test? I used Agilent DB-1HT column on Shimadzu GC.
Thank you in advance!
Falguni
Please look at the following below links which may help you in your analysis:
https://www.nwmissouri.edu/naturalsciences/sds/0-9/1-Dodecanethiol.pdf
http://datasheets.scbt.com/sc-255824.pdf
Thanks
I looked it up in PubChem (Google) "Lauryl mercaptan"
I hope the attached file is interactive.
Thank you all for your answers!
If the Thiol is oxidizing and forming disulfide, how do I overcome to this issue? Make up gas is Helium and I am prepping solution in Glovebox (air-free). What could be the possible reason, that the oxidation reaction is taking place?
Hello,
In my standard solutions (10,15,20,25,30,35 ppm), the second peak starts appear from 25 ppm.
Today I did an experiment. I kept all standard solutions air free and loaded individuals on the instrument right before starting run. I did get the same result as I got in the previous run in which I loaded all standards together on instrument (second peak appears from 25 ppm standard injection).
Then I ran 15 ppm standard which I kept in GC vial in air, I did not get the second peak, same as the previous run.
Can anyone help me to figure out that what is going on here. I make stock solution of 1000 ppm (25mg in 25mL) in DCM by adding 0.7mL of of BSTFA and dilute it further to make series of standard solutions.
Thanks,
Falguni
- Badges
- Science topic
- Similar topics
- Analytical Chemistry
- Column