Hi Giovanni

HPLC with ICPMS detection may be an option in your case. Check the work of Joerg Feldmann in Aberdeen. His group (and others) have done a lot on method development in this direction.

Hope this helps

Thanks for the answer, I will try the work of prof. Joerg Feldmann but are looking for a rapid screening test to test my enzyme.

Typically, Arsenic concentrations have been determined by an acid digestion and 'hot' vapor (Sodium Borohydride reduction to generate Arsine gas) atomic absorption spectrometry (AAS) like environmental samples.

Thanks for the answes

IC coupled to ICP-MS or ICP-OES are about your only choices. You'll get speciation of the monomethyl, dimethyl and the two inorganic forms of arsenic. If you run it out a bit you'll pick up the ethyl arsenics, if they are present.

Run time is pretty short, on the order of 7-10 minutes per injection. Sensitivity is exceptional.

Thank you, I propose that to my boss :)

Dear Giovanni,

You may like to consider the use of ion chromatography, using a conductivity detector.

As dimethylarsinic acid and monomethylarsonic acid in particular, are anions, they and some other arsenic species may be detected using an anion column, such as Hamilton PRP-X100, 150 x 4.1 mm, with a 4mM Phthalic acid, pH 4.2 mobile phase.

A cation column may be used to detect and measure the cation forms of arsenic.

Kind regards,

Ade Kujore

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Cold vapor AAS is a relatively inexpensive method and can be quite sensitive.