I hope this is going in the right section of the forum.

On Sherlock's website, The Science of Deduction, there is a reference to Analysis of Perfumes. Now I have done a bit of research and have managed to find out the following:

Firstly, this is a direct reference to the original stories where in The Hiund of the Baskervilles Sherlock Holmes states, 'There are seventy-five perfumes, which it is very necessary that a criminal expert should be able to distinguish from each other, and cases have more than once within my own experience depended upon their prompt recognition.'

Secondly, in the series Sherlock, he uses his knowledge of perfumes to tell that Donovan has been staying overnight with Anderson.

Thirdly, Staffordshire University in the UK actually has research going on at the moment on the analysis of perfumes and deodorants specifically for forensic use. There are also other websites with perfume analysis especially related to sick-building syndrome. It would also appear that gas  chromatography-mass spectrometry are difficult to use to get good analysis because perfumes' ingredients are so complex.

Finally, there is a book entitled Perfume: The Story of a Murderer by Patrick Suskind, which I thought was a weird coincidence.