Chromatography Forum

Newspaper posted that some of commercail shampoo availble in the local market are carcogenic. I look about this issue in the internet and found that the material may be 1,4-dioxane. I bought those shampoo and would like to test it. I thought it could be done by headspace technology. Any body work with this case before?

Hi

Not with dioxane in shampoo but in pharmaceuticals and used headspace then.
You have an intresting sample matrix so I would suggest that you use standard addition to quantify dioxane.

Personally I would likely start with adding 0,5000-1,0000g of a sample directly to a HS vial and add 1-4,0ml of water and compare with a pure water based standard.

Dioxane has a bp of around 100°C if recalling right so a headspace temperature of 60-70°C would likely be a good start.

Use headspace GCMS, we've done that here. Dioxane at trace levels is present whenever ethoxylated materials are used, sucha s most nonionic surfactants. Suppliers use vacuum stripping to keep the dioxane levels low in their raw materials, but some always remains.

Am I wrong, or is dioxane wickedly hard to get out of water for headspace? K value of 1618 according to table in Restek guide. Is there a better solvent to use for this application?

Best regards.

Am I wrong, or is dioxane wickedly hard to get out of water for headspace? K value of 1618 according to table in Restek guide. Is there a better solvent to use for this application?

Best regards.

Hi

Possibly, however digged in the archive while I was roamining it for something else and found an old method for dioxane:

In short: a DB-624 column (30m*0,32mm* 1,8um ) split ratio about 10. HS oven at 60°C. Sample/std vials (10ml) all contained 1g of sodiumsulfat (hmm a bit over the top i think to get a salt out effect). The std solution in std vial was 5ml containing a total of 10ug dioxane.

Not the nicest/biggest peaks if recalling right but clearly visible.