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Subject: Compost Teas: 24 hour, EM, IM, BD & fermented plant extracts

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  • From: Graeme Gerrard <ggerrard AT resonant.com.au>
  • To: compostteas AT lists.ibiblio.org
  • Subject: [Compostteas] chromatography
  • Date: Sun, 14 Jul 2002 18:05:29 +1000

Hi All,
There are several chemicals that are used in BD for chromatography, as a developer. Silver nitrate is perhaps the least harmful (others are iron sulphate and gold chloride, for example). The MSDS on silver nitrate doesn't indicate it is particularly nasty. The sodium hydroxide (caustic soda) is much more of a worry!

The procedure is very simple, but you need to be very careful and precise when doing chromatography to get good results. If it proves useful though, it may be an excellent technique people can use for testing their own tea quality. You could try the method you suggest (with Whatman #1s), but you may not see much at all.
(I am using Pfeiffer's method, as outlined in "Chromatography Applied to Quality Testing" 1984, Bio-Dynamic Literature, Wyoming, USA.) But it is essentially the same as methods used by other BD chroma makers.

I'd love to do some testing of teas but I am in the midst of moving to a new property (south coast of New South Wales) and will have no time in the next little while.
I know that there is a European researcher coming to the BD conference in NSW next month to talk on chromatography and sensitive crystalization and to later run some courses. Contact the BDFGAA <http://www.biodynamics.net.au/> for more info.
Coffee filter papers? Best used for making coffee!



For use of chromatography in BD quality testing check out:
<http://www.resonant.com.au/chromatography>

The chroma tests in BD testing requires the use of silver nitrate to fix or develop the colors. I don't think that is a reasonable thing for most grower's to
have to use. The basic idea is good, having to use a nasty chemical to develop the chroma is not primo. Could we avoid using silver nitrate in this method?

What Kirk suggested to me was putting a drop of the tea on a paper towel. Using Whatman filter paper #1 would be better, because the quality of the paper is more
uniform. Let the drop spread out from the center of the filter disk. The smaller molecules move more rapidly out from that center drop. The pattern that
develops might be indicative of the tea quality.

We would have to do some testing to see if this would actually be indicative of good tea. So, who wants to work on this with me?

Elaine Ingham
Soil Foodweb Inc.



--__--__--

Message: 5
From: "Jeff Lowenfels" <jeff AT gardener.com>
To: "Soil Foodweb, Inc." <info AT soilfoodweb.com>,
<compostteas AT lists.ibiblio.org>
Subject: Re: [Compostteas] Re: Chromatography
Date: Fri, 12 Jul 2002 17:50:48 -0800

Doctor E,

I am in. How do you want to do it?

In fact, why don't we all try it when we send in our next few samples. It
shouldn't take us long to get some idea
if this is going to work.

How do you want to standardize this? Wouldn't it be easier to simply start
out using coffee filters (half in jest and half serious)

--
Graeme Gerrard
Resonant Multimedia
PO Box 39 Bega NSW 2550
ph:(02) 6494 4376 mob. 0414 396 754
ggerrard AT resonant.com.au




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