charla berens
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Joined: Mon Sep 03, 2007 5:48 pm

Inexpensive lead content test or method?

Postby charla berens » Mon Sep 03, 2007 5:54 pm

Does anyone know of an inexpensive way to test herbs for their lead content? Thanks for your help!

Posts: 1055
Joined: Mon Oct 16, 2006 11:47 am

Postby MelissaB » Mon Sep 03, 2007 6:49 pm

Is it important that you know how much lead, or will the presence/absence of lead work for your experiment? I found this site (note: I know nothing about this website other than Google pulled it up, and ScienceBuddies does not endorse any online stores) via Google, and it has swabs that turn colors if there's lead in dust: I would suggest drying the herbs and then crumbling them up into dust, then using the swabs.

I pulled several similar products up--one where you can test your child's toys to see if there's lead on their surfaces, for example. You may want to look around at the different products; just put 'test for lead' into Google and you'll get tons of hits.

Former Expert
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Joined: Mon Aug 29, 2005 10:02 am

Postby geoffbruton » Thu Sep 06, 2007 8:42 am

Hi Charla,

As Melissa said, one of the issues you will need to decide upon is whether you are interested in the presence only of lead (termed qualitative analysis), or the amount of lead present (termed quantitative analysis) in the herbs.

Whilst there are several different types of test kits available on the market, you need to appreciate how the test kit works - some of the kits are not specific for lead, and so may give you a false positive.

The basic principle involves dissolution of the lead in a weak acid, followed by the analytical technique of choice.

There are a variety of different analytical techniques available for the quantitative and qualitative analysis of materials suspected to contain lead. However, some of the more elegant instrumental techniques would most likely be both unavailable through your school and also prohibitively expensive.

A colorimetric test would probably be the least expensive and easiest to set up.

Please research any terms that I have used that are unfamiliar to you. After that, please let us know what your objective is, and what you were able to find yourself using literature sources and the internet.

Good luck!
Geoff Bruton
Firearm & Toolmark Section
Ventura County Sheriff's Department
Forensic Sciences Laboratory

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