Comparison of droplet-size distribution and matrix effects in flame atomic absorption spectrometry applying hydraulic high-pressure/perfomance nebulization and pneumatic nebulization

Abstract

The solution to be analysed is forced through a very fine nozzle (20 μm) under a pressure of 100–400 bar (10–40 MPa) using a liquid chromatographic pump, resulting in an aerosol for sample introduction in atomic absorption spectrometry (AAS). Compared with pneumatic nebulization, the hydraulic high-pressure/performance nebulization (HHPN) causes an essentially smaller proportion of large droplets (> 16 μm): HHPN, 1%; standard flame AAS nebulization, 7%; inductively coupled plasma nebulization, 34%. The smaller droplets of the HHPN aerosol lead to higher sensitivity (2-fold in signal height, 5–6-fold in signal area) and to lower matrix interferences (better evaporation of smaller droplets in the spectroscopic source).