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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: jtmeow on March 25, 2008, 08:22:27 PM

Title: cold vapor AAS
Post by: jtmeow on March 25, 2008, 08:22:27 PM

Hello,

First off, I am a graduate student in wildlife biology = chemically clueless.  I am working out methods to determine total mercury content from otter fur.  I am currently familiarizing myself with AAS techniques.  Apparently, mercury must by analysed using cold vapor AAS.  There is a Perkin Elmer Aanalyst 400 at my university.  I have read up on this instrument on line (to the best of my understanding) but still have questions.  Can the "cold vapor" technique be used with most flame AA instruments, or is a different instrument used? 

Thanks,
jtmeow

Title: Re: cold vapor AAS
Post by: Arkcon on March 25, 2008, 08:33:39 PM

Unfortunately, yes, the cold vapor AAS is a specialized instrument just for mercury determination.  Mercury has too low of a vapor pressure to be analyzed by flame AAS, you simply lose too much to account for, even with the standards.  As I recall, even the sensitivity and accuracy of ICP is not the best for traces levels of mercury.