Chelator question

In a shampoo formula, sodium gluconate is called for but I don’t have any. Would I be able to use tetrasodium glutamate diacetate instead? Or is there another chelating agent you recommend?

Comments

  • PhilGeisPhilGeis Member, Professional formulator
    Gluconate isn't much of a chelator - use NaEDTA
  • PaprikPaprik Member
    Yeah, tetrasodium glutamate diacetate is a good chelator. And @MarkBroussard uses it. Typical usage rate is 0.2 to 0.3%.

    But as mentioned by Phil, NaEDTA's are good option too. 
  • @Paprik does terrasodium glutamate diacetate have any incompatibilities with other ingredients that you know of?
  • francisafrancisa Member
    @PhilGeis and @Paprik I used Disodium edta and found it quite difficult to dissolve in my water phase. Why is that? 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @francisa

    You should be perfectly fine using GLDA to replace Sodium Gluconate.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • PhilGeisPhilGeis Member, Professional formulator
    what is your pH?
  • francisafrancisa Member
    @PhilGeis I didn’t take the pH of my water phase. If it’s too low will that affect the solubility of the Disodium edta? 
  • Good morning @francisa
    Does your disodium edta dissolve in water? Have you tried dissolving it before the other ingredients?
    Lab Assistant to a Cosmetic Formulator.
  • It will take a little while to go in but it will. Are you using more than 0.10%?
  • francisafrancisa Member
    @KimberlyLars yes I am using more than .10% 
    could that be the issue?
  • francisafrancisa Member
    @Adamnfineman I have not tried dissolving it in water first. Good idea. 
  • PharmaPharma Member, Pharmacist
    edited May 11
    EDTA becomes increasingly less soluble at low pH (and vice versa); GLDA's solubility is less pH sensitive. However, you use it at a low concentration and the main issue you'll see is the slow speed at which they dissolve (you're unlikely hitting solubility limits). To speed up dissolution, use a smaller amount of water with a higher pH to make a concentrated stock solution. Some shampoo ingredients come at high pH, maybe use these to dissolve the chelates (especially if you make products for your personal use) :wink: .
    BTW EDTA is often more effective (stronger binding at lower pH) whilst GLDA is better for nature in several regards.
  • GraillotionGraillotion Member
    edited May 12
    Pharma said:
    EDTA becomes increasingly less soluble at low pH (and vice versa); GLDA's solubility is less pH sensitive. However, you use it at a low concentration and the main issue you'll see is the slow speed at which they dissolve (you're unlikely hitting solubility limits). To speed up dissolution, use a smaller amount of water with a higher pH to make a concentrated stock solution. 
    GLDA sold by the USA re-packers is almost always coming in a liquid solution, so for the small timers...GLDA...is NO SWEAT.

    TSGD (Tetrasodium Glutamate Diacetate) | MakingCosmetics

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  • francisafrancisa Member
    @Pharma thank you so much for such a thorough answer. I think I’m going to try using the GLDA.
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