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- Posts: 27
- Joined: Tue Apr 16, 2013 9:51 am
Dear all!
I have to analyze chloroform in air. I need about 1 ug/m3 detection limit.
I have an 5890 GC with ECD detector. We are trying out Porapak N tubes with methanol desorption (i cant use CS2 with this type of ECD). For recovery i injected directed 50 ul 20 ug/ml THM mix into the glass wool in the tubes and used pump for 30 min on the other side to dry it out.
After this i put everything ( wool too) into a 5 ml vial with cap i added 4 ml methanol and and sonicated it for 10 min. After this i divided it in 2 2 ml vial capped it then i measured it with GC-ECD.
I got 4-500 ng/tube for chloroform and 1000-1200 ng for other 3 compounds (CHCL2Br, CHCLBr2, CHBr3).
If anybody had to measure same before, any advice or recovery rates can tell pls? I tryied to search for desorption efficiency in literature but i wasnt able to find any ( pleny for TD and for CS2 but for methanol not too much.
Thanks for helping me!
Erdno
I have to analyze chloroform in air. I need about 1 ug/m3 detection limit.
I have an 5890 GC with ECD detector. We are trying out Porapak N tubes with methanol desorption (i cant use CS2 with this type of ECD). For recovery i injected directed 50 ul 20 ug/ml THM mix into the glass wool in the tubes and used pump for 30 min on the other side to dry it out.
After this i put everything ( wool too) into a 5 ml vial with cap i added 4 ml methanol and and sonicated it for 10 min. After this i divided it in 2 2 ml vial capped it then i measured it with GC-ECD.
I got 4-500 ng/tube for chloroform and 1000-1200 ng for other 3 compounds (CHCL2Br, CHCLBr2, CHBr3).
If anybody had to measure same before, any advice or recovery rates can tell pls? I tryied to search for desorption efficiency in literature but i wasnt able to find any ( pleny for TD and for CS2 but for methanol not too much.
Thanks for helping me!
Erdno
