By Anonymous on Friday, September 27, 2002 - 03:14 pm:
Hi,
I wonder if it is possible to identify Br- ion by ESI-MS. Thanks for the comments.
By Kostas Petritis on Friday, September 27, 2002 - 06:25 pm:
Theoretically yes, in negative ion mode, but the chemical noise at this mass to charge ratio is so high that you won't have any sensitivity.
As Br- can not be further fragment you can not use MS-MS for this. I think that ion chromatography is the best way to go for this type of analysis.
By Anonymous on Friday, October 4, 2002 - 01:05 pm:
IC-MS using an AS11 column with hydroxide eluent and an ASRS-ultra suppressor coupled to MSQ mass spec with negative elecrospray interface works great. The suppressor removes the background so there is no chemical noise. I prefer to use 2-mm format but 4-mm works well too. The masses for selected ion monitoring (SIM) are 79 and 81 due to the isotopic abundance of Br. Detection limits are in the parts-per-trillion. Dionex sells all of this stuff.