Determination of water content in hair samples by Karl Fischer Titration

A good way to evaluate the moisturising performance of a shampoo or a conditioner is to determine the water content of the hair before and after treatment with the relevant product.

Historically the analysis of water in hair was not only time consuming but very inaccurate. However, with a technique developed by Metrohm, analysis times are shorter and the reproducibility of results is significantly better. Using the 774 Oven Sample Processor in conjunction with the 831 KF Coulometer analysis times are typically 3-5 minutes and RSDs on results are less than 1 per cent, and more importantly for the hair donor, sample sizes are very tiny. Manual sample preparation is reduced to a minimum, just weigh, crimp and analyse. The sample is introduced into an oven where the water evolved is titrated in the KF coulometric cell.

The refined methodology of the 774 Oven Sample Processor brings decisive advantages:

• Strictly reproducible analysis conditions for all samples
• No contamination of the oven, consequently there is no carryover and memory effects
• Improved water release as the carrier gas passes directly through the sample
• Considerable savings in time and money, e.g. less reagent costs, no more acid and solvent extraction.