Octadecyl immobilized surface for precipitate collection with a renewable microcolumn in a lab-on-valve coupled to an electrothermal atomic absorption spectrometer for ultratrace cadmium determination.

摘要: Octadecyl immobilized surface was, for the first time, proved to be a superb precipitate-collecting medium. Surface charge effect was assumed dominate adsorption of cadmium hydroxide precipitate, facilitated by electrostatic interaction between negatively charged C18 bead and positively clusters. Residual silanol groups on C18-immobilized silica did not contribute precipitate adsorption. A novel procedure ultratrace preconcentration proposed incorporating renewable microcolumn in lab-on-valve system. Cd(OH)2 adsorbed onto surface, which afterward eluted with 20 μL nitric acid (1%) quantified detection electrothermal atomic absorption spectrometry. An enrichment factor 28 limit 1.7 ng L-1, along sampling frequency 13 h-1 were obtained sample consumption 600 within concentration range 0.01−0.2 μg achieving precision 2.1...