Chromatography Forum

HI,

is there any method (apart from the conventional titrimetry) for determining the SLS content in a drug? 'coz though the regular titrimetric method is easy to carry out ...i don't think its accurate....is there a possibility of using lc method(i mean just asking)

Lc is problematic because "SLS" is actually a mixture of isomers and chain lengths.

Just out of curiosity, why do you think the standard titrimetric method is inaccurate?

the sls content in the drug is generally very less, the concentration of benzethonium chloride used is around 0.1mM and the colour change at the end point is not very clear.....there's a scope for manual errors. i'm confused whether theres a batch to batch variation in the drug or is it an analytical error!! (is it possible to have a potentiometric method for it? i mean i know it is possible but then we would need a surfactant electrode right)

Anuradha,

SLS is fairly straightforward to characterize and quantitate by way of several different methods. You find more about this separation using a column designed for separating surfactants from Dionex at the following link (sodium dodecyl sulfate, the main component in SLS is analyte 6 in the chromatogram): http://www1.dionex.com/en-us/columns_ac ... 25924.html If you are really working with a mixture rather than a pure compound, you will need to obtain a standard for each of the components (normally there are only four components: the C10, C12, C14 and C16 sulfates and all can be purchased as pure materials from Fluka).

thanks a lot for the info