Sodium Lauryl Sulfate Extraction from Lotion

[shemesh199]

Hi all,

I would like to ask your knowledge and ideas on how to best extract Sodium Lauryl Sulfate (SLS) from various lotion and ointments. I have been using (pentane:ethyl acetate:ethanol 1.5:1:1) as an extraction buffer with pretty good recoveries. But I am considering to do a more simple approach such as a standard ethyl acetate wash, not sure if the pentane and ethanol need to be in the mix to pull out the surfactant. Our analysis method is HPLC-MS-MS.

Are there any other approaches or somebody with experience in this. For all that do not know SLS is an anionic surfactant, it is a 12 carbon tail attached to head sulfate group.

I would appreciate any comments, tips, or tricks.

Many Thanks

[Consumer Products Guy]

It's not that clear to me whether you are trying to analyze for the SLS, or are just trying to remove it from your matrix.

I'm experienced with SLS and other consumer products stuff (Duh !!!) but need clarification if I'm to offer assistance.

[shemesh199]

I am analyzing the content in ointment. I need to perform a suitable sample prep to shoot it, it seems I need to extract it and analyze content via LC-MS-MS.

Thanks again.

[shemesh199]

I am analyzing for SLS itself.

[Consumer Products Guy]

I am analyzing for SLS itself.

Why not just titrate with standardized cationic like in ASTM Method D 3049-75?

You can precipitate anionic with Ba+2.

Much easier than hydrolyzing with acid/heat and extracting out the fatty alcohol from the SLS.

You do know that SLS typically also contains C14 and C16, and often some C10?

[shemesh199]

Actually I have been performing a simple extraction using pentane ethyl acetate and methanol