Recently Baginski and Meinhard have shown that when high-solids matrices were aspirated into an ICP torch via a Meinhard concentric nebulizer, plasma instability, and ultimately plasma failure, resulted from salt deposits in the sample delivery tube of the torch, rather than in the nebulizer. They have compared the performance of the commonly used type A and B nebulizers with a new type C model, which has a recessed capillary tip, by continuously aspirating an aqueous solution containing 410 g/L hydrated aluminum sulphate until the plasma failed. Examination of the torch and nebulizer after plasma failure revealed the cause of failure to be blockage of the delivery tube rather than the nebulizer. Furthermore it was shown that if the new type C nebulizer was used, the plasma operated for a much longer period before failure. In no cases did the authors observe blockage of nebulizers while in use.
David G. Cobbold, "Comments on the Analysis of High-Solids Matrices Using the Meinhard Concentric Nebulizer in ICP Atomic Emission Spectroscopy," Appl. Spectrosc. 40, 1242-1244 (1986)