LIBS elemental analysis of human nails with metal sample holder contamination

[Avery_quinn]

Hi, I'm trying to use LIBS technique to figure out elemental analysis of human nails. But every time i run the experiment, i get the emission line of metal instead. The sample holder is indeed made up of metal. What should I do to overcome this problem?

Since i have small size sample, I'm using focusing lens with fl 15cm to focus the laser but there's no spark. Should i stop using lens? or should i use lens with different fl? Thanx!

 

[Hyo X]

Ive never used LiBS but try
-increasing your sample volume
-having the laser focus only on the sample
-run a baseline with no sample and subtract this baseline signal from the sample measurement

 

[Avery_quinn]

thank you for your advice.