Optimization of hydraulic high pressure nebulization; droplet size distribution of the aerosol and efficiency of the nebulization.

Hydraulic high pressure nebulization (HHPN) is the most effective and advan ced sample introduction technique in atomic spectroscopy. One of the most c rucial element in this technique is the Pt/Ir plate with a 10-30 mu m hole and as the most important technical modification, this plate was substitute d with a diamond plate having higher mechanical and chemical resistance. To make the handling and changing more easily, the diamond inlet was fixed in to a threaded titanium socket. Sample introduction parameters of hydraulic high pressure nebulization were studied using this diamond inlet for severa l organic solvents and aqueous mixtures used as eluent in high pressure chr omatography. A fast and accurate method was developed to measure the sample introduction efficiency of high pressure nebulization. The drop size distr ibution of the aerosol was studied by a cascade impactor using different pa rameters. The optimal sample introduction parameters were determined by con sidering the nebulization efficiency, drop size distribution data as well a s the analytical signals measured by a flame atomic absorption spectrometer . The most effective impact bead turned to be a small glass sphere with the o ptimal distance of 15-17 mm from the outlet hole of the nebulizer. There is an optimal sample introduction rate for the most effective nebulization in case of every nozzle diameter. Organic solvents used for extraction or as chromatographic eluents in atomi c spectroscopy usually have good nebulization efficiency. In case of 10 mu m nozzle diameter the nebulization efficiency is 85%, 87% and 90% for aceto nitrile, methanol and MIBK, respectively. This fact can be explained with t he unusually small drop diameter of the organic aerosols.