Abstract Sapphire is presented as a high temperature and corrosion resistant material of an optical tube of an atomizer for volatile species of Ag generated by the reaction with NaBH4. The modular atomizer design was employed which allowed to carry out the measurements in two modes: (i) on-line atomization and (ii) in situ collection (directly in the optical tube) by means of excess of O2 over H2 in the carrier gas during the trapping step and vice versa in the volatilization step. In comparison with quartz atomizers, the sapphire tube atomizer provides a significantly increased atomizer lifetime as well as substantially improved repeatability of the Ag in situ collection signals shapes. In situ collection of Ag in the sapphire tube atomizer was highly efficient (> 90%). Limit of detection in the on-line atomization mode and in situ collection mode, respectively, was 1.2 ng ml− 1 and 0.15 ng ml− 1.