Selection of Conditions for the Dynamic Sorption Preconcentration of a 1,1-Dimethylhydrazine Derivative (4-Nitrobenzaldehyde N,N-Dimethylhydrazone) on Hydrophobized Silica

The type of mass transfer in the sorption of 4-nitrobenzaldehyde N,N-dimethylhydrazone (BDH) on silica chemically modified with hexadecyl groups was determined using the linear model of sorption dynamics, and distribution and mass transfer coefficients of hydrazone were calculated. Optimal conditions of the dynamic sorption preconcentration and desorption of BDH and its subsequent determination by reversed-phase high-performance liquid chromatography were proposed. The detection limit of the compound for preconcentration from a sample of 100 mL was 1 μg/L.