A nozzle for easy introduction
Sample introduction for analytical chemists is about to become a lot easier, thanks to a group of German scientists and their new nebuliser.
Peter Walzel's group at Dortmund University has developed a pneumatic nebuliser, the miniaturised pneumatic extension nozzle (PEN), for sample introduction in inductively coupled plasma optical emission spectrometry (ICP-OES)
Nebulisers make the fine aerosols needed to get samples into the plasma in ICP systems. Pneumatic versions are the most commonly used.
Walzel's group claims that its PEN can greatly enhance detection limits compared to classical pneumatic nebulisers. This is because the PEN produces higher numbers of droplets that are the right size to make it into the plasma.
Walzel and his colleagues studied the droplets being formed under different conditions and with different nozzle geometries. By using the nozzle diameter as a linear size scale, they came up with a model for predicting the mean droplet diameter, and so be able to change the nozzle size to get the best results for a given sample.
The team emphasises the many other advantages offered by their PEN design over commonly used nebulisers; it is easy to clean, is robust and the risk of it becoming blocked is low. As well as this it can be adapted to various ICP instruments. Developing its studies further, the team intends to modify the nebuliser for use with flame atomic absorption spectrometry.
S Groom et al, J. Anal. At. Spectrom., 2005 (DOI: 10.1039/b410772c)