Ramiro and Johan,
I looked for analytical results for Ag in algae reference materials in my
database and came up with the following paper:
Hany A. Amer, Peter Ostapczuk and Hendrik Emons, Quality assurance in
measuring the elemental composition of the alga Fucus vesiculosus, J.
Environ. Monit., 1999, 1, 97-102.
Dr. Michael Sperling
European Virtual Institute for Speciation Analysis
48149 Münster, Germany
Tel.: +49 251 980 2680
Fax: +49 251 980 2681
EMail: [log in to unmask]
Von: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's).
[mailto:[log in to unmask]] Im Auftrag von Johan Schijf
Gesendet: Montag, 19. September 2011 15:43
An: [log in to unmask]
Betreff: Re: Ag CRM
now that I am back in my office I was able to do some more digging, but came
up empty. The IRRM standard BCR-279 (Ulva lactuca, a green marine macroalga)
has no values for Ag at all. IAEA used to have the standard IAEA-140/TM
(Fucus sp., a brown marine macroalga) which had an information value for Ag
of 78 ppb (based on dry weight), however it looks like that material is no
longer available. They now supply the standard IAEA-413 (Chlorella sp., a
green freshwater microalga) but this again has no values for Ag.
The best thing might be to pick an algae standard that is suitable for you
(Chlorella might be closest) and then see if there are any Ag values
reported in the literature. They would not be certified values, but it might
help to get you started. Alternatively, you could go with a non-algae plant
standard that has certified Ag values. Spinach leaves are somewhat similar
to algae in composition, but their Ag values would likely be very different
since they take it up from soil, not directly from the water. Algae
(especially macroalgae) also tend to be high in phytoliths (i.e. Si), which
can make the digestion more challenging. Ulva contains about 20,000 ppm Si
which usually leaves me with a layer of 'sand' in my digests. This will
probably be less of a problem for microalgae like Pseudokirchneriella
because they have less need to be structurally rigid.
I'll keep an eye out and let you know if I find anything.
"[...] more than half the banana genome is shared with humans (a fact more
evident among some of my acquaintances than others)" - Sir Robert May
Dr. Johan Schijf
Assistant Professor, Aquatic Environmental Geochemistry
UMCES/Chesapeake Biological Laboratory
P.O. Box 38, 1 Williams Street
Solomons, MD 20688-0038
Tel. (410) 326-7387 (office) 7392 (lab)
Fax (410) 326-7341
e-mail: [log in to unmask] Manuel Ramiro Dias Pastorinho
<[log in to unmask]>:
> Thanks Daniel and Johan for the feedbacks, they are much appreciated!
> we are conducting investigation in the Ag transference (bulk and
> nanoparticled) in a simulated freshwater food chain and we are using
> Pseudokirchneriella subcapitata (formerly known as Selenastrum
> capricornutum) as producer.
> That is why I was so surprised by the relative absence of CRMs for
> Ag, especially since the nanoparticles are kind of a hot topic at
> the moment.