Preparation of hollow porous molecularly imprinted polymers and their applications to solid-phase extraction of triazines in soil samples

Abstract

Porous polymers have aroused increasing interest due to their controllable hole(s) structure in favor of mass transfer. In this work, three types of porous molecularly imprinted polymers (MIPs) using atrazine as template, namely single-hole hollow molecularly imprinted polymers (s-HMIPs), multihole hollow molecularly imprinted polymers (m-HMIPs) and porous solid molecularly imprinted polymers (ps-MIPs), were prepared, and applied as solid-phase extraction (SPE) sorbent for selective preconcentration and specific recognition of triazines in soil samples. For porous MIPs, most of the binding cavities were located in the proximity of the surface, which remarkably facilitated template removal and mass transfer. The resultant atrazine imprinted porous polymers of s-HMIPs and m-HMIPs exhibited more than triple imprinting capacity for triazines compared to the ps-MIPs, while they were all greatly superior to that of the non-imprinted polymers (NIPs). Accordingly, the s-HMIPs employed as SPE sorbent presented much higher extraction efficiency for several triazines based on the large specific surface area and high adsorption capacity in comparison with the commercial C₁₈ column. The validated method was also successfully applied to soil sample analysis, and satisfactory recoveries were attained, such as 73.5–102.0% with the precision of 1.17–4.24% for five triazines at 10 μg L⁻¹. The s-HMIPs-SPE proves to be a highly-effective cleanup and enrichment method for simultaneous separation and sensitive determination of triazines in complicated samples.