-
Test for Metallic Salts
Hey, been out of the real chemistry for a long time so pardon my beginner question:
I am importing natural herbs and other ingredients from overseas. The claim ius tht they are “organic” and “all-natural” ie 100% pure.
What chemical tests can I do on the ingredients (indigo leaf powder for hair, henna powder) to ensure that
1) no metallic salts are added
2) they are truly organicThe place has certifications but I want to be SURE.
-
10 Replies
-
As far as 2) goes, there is no test for “organic”. The only thing you can do is trust suppliers documentation.
-
Indian Standard IS 7159:1984 lists a number of test methods for henna powder, including testing for adulterants and extraneous sand - it may very well be helpful for your purposes
flame atomic absorption spectrocopy is most rigorous way to test for metals, but there are many qualitative methods too; for instance, certain dyes (methylthymol blue, xylenol orange, eriochrome black T) change colour in the presence of metal ions
-
What are you using the natural herbs for? What benefit are they providing?
If there is a quantifiable benefit, you could conduct a test to see if they meet your requirements. If there isn’t a quantifiable test…well that’s probably a problem.
-
Thanks Bill_Toge fir the info. I guess the ISB (insian stndards bureau has all that info for exporters..)
Perry, I am using it for an all natural hair colour.
Here’s the thing:
I used that test that they do in salons, the “compatibility test” ammonia + 40volume hydrogen peroxide mixed in henna powder and waited for a reaction (it is supposed to remain inert if no metallic salts are present) I bought a sample of EVERY local providers’ natural organic henna powder and they ALL reacted.,.. so I grew suspicious of the test…Any ideas?
Thanks
-
@Khadijah the standard is available to anyone who pays for it, e.g. here
regarding the ‘compatibility test’: the mixture will become coloured if there are oxidative dye precursors (e.g. PPD, resorcinol) present
in my experience these are the most common additives/adulterants in ‘natural’ henna powder, and can be detected by the thin-layer chromatography method described in the standard
if you can get a sample of pure lawsone (the active colourant in henna; systematic name 2-hydroxy-1,4-naphthoquinone, CAS # 83-72-7), make a 1% solution of it in water and test that solution under the same conditions, you’ll know for sure whether or not the ‘compatibility test’ is valid
-
I poured a teaspoon of the henna powder into the ammonia + 40volume hydrogen peroxide mix and got a highly exothermic reaction… for every sample for evey single natural brand i tried… don’t know what to make of tht.
as for HPLC, back in the day i ued to work in a chromatog lab on campus so I coulda run samples there but now I cant find a place that wants to charge me less thn $1000 o=per test. Can’t exactly afford that right now.,.. Is there way to get HPLC testing for less?
-
I don’t understand why you should get an exothermic reaction from ground-up dried plant leaves. It’s cellulose, right? Try the same experiment with some other type of ground dried plant leaves. Tea, for instance. Do you still get a reaction?
-
you don’t need to use HPLC; if you’ve got a mercury-vapour UV lamp, any organic adulterants will be visible on a thin-layer chromatography plate
if you have pure henna, the only substances visible on the plate should be lawsone (Rf = 0.4) and chlorophyll (coincident with the solvent front)
-
I don’t understand why you should get an exothermic reaction from ground-up dried plant leaves. It’s cellulose, right? Try the same experiment with some other type of ground dried plant leaves. Tea, for instance. Do you still get a reaction?
I know! and I got the test from EVERY single brand. Ok I will try soe tea and maybe some cinnamon bark.
What is the exothermic reaction indicating?
-
@Bill_Toge
I obtained a copy of the Indian Standard IS 7159:1984-thank-you for the suggestion! I am having difficulty obtaining specific results reports from the Bureau for batches tested from suppliers.
Any idea who else would hold copies of the batch test reports done under IS 7159:1984
Log in to reply.