Home Cosmetic Science Talk Formulating General Science Test for Metallic Salts

  • Test for Metallic Salts

    Posted by Khadijah on March 6, 2018 at 2:52 am

    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 organic

    The place has certifications but I want to be SURE.

    Khadijah replied 6 years ago 5 Members · 10 Replies
  • 10 Replies
  • gld010

    Member
    March 6, 2018 at 4:20 pm

    As far as 2) goes, there is no test for “organic”. The only thing you can do is trust suppliers documentation.

  • bill_toge

    Member
    March 6, 2018 at 7:01 pm

    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

  • oldperry

    Member
    March 6, 2018 at 8:33 pm

    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.

  • Khadijah

    Member
    March 8, 2018 at 5:36 pm

    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

  • bill_toge

    Member
    March 9, 2018 at 8:55 pm

    @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

  • Khadijah

    Member
    March 10, 2018 at 3:30 am

    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?

  • belassi

    Member
    March 10, 2018 at 9:12 pm

    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?

  • bill_toge

    Member
    March 11, 2018 at 4:14 pm

    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)

  • Khadijah

    Member
    March 12, 2018 at 6:47 am

    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?

  • Khadijah

    Member
    March 12, 2018 at 6:53 am

    @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

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