High-temperature hydraulic high-pressure nebulization: A recent nebulization principle for sample introduction

High-temperature hydraulic high-pressure nebulization (HT-HHPN) is a recent development in the field of high-efficiency nebulization techniques in atomic spectrometry. Typically in HHPN, the liquid to be nebulized is forced through a highly turbulent hydraulic nozzle of diameter less than or equal to 20 mu m by means of an HPLC pump at a pressure of > 20 MPa (200 bar); in this study the liquid was heated to temperatures up to 300 degrees C. The residence time of the liquid inside the critical part of the nozzle is less than 100 ns. The nebulization effect is based on the shock waves of the hydraulic high-pressure nebulization and on the spontaneous vaporization of part of the liquid precisely defined by temperature. In contrast to thermospray techniques, the vaporization takes place only outside the HT-HHPN nebulizer. Saturated salt solutions may be nebulized directly. In FAAS, the aerosol yield is approximately 80% and thus surpasses all conventional nebulization systems. With desolvation, HT-HHPN is compatible with ICP-AES, resulting in about 10-fold improved detection limits.