Solid-phase extraction disk based on multiwalled carbon nanotubes for the enrichment of targeted pesticides from aqueous samples

Abstract

A sensitive method for the determination of six varying polarity pesticides (imidacloprid, acetamiprid, carbendazim, simazine, linuron, and tebufenozide) based on a solid-phase extraction disk with multiwalled nanotubes is proposed.A dispersion of multiwalled nanotubes in a surfactant aqueous solution (Triton X-100) was used for the preparation of the solid-phase extraction disk. The effect of surfactant on the functional groups of multiwalled nanotubes was examined by applying temperature-programmed desorption. It was found that this treatment increased the amount of oxygen groups of treated multiwalled nanotubes comparing with untreated ones. The factors that may influence the adsorption and recovery such as the kind and volume of eluent, volume, flow rate and pH of sample were investigated and optimized. Under the optimized conditions, the maximal enrichment factors for low polar pesticides are ranging from 4000 to 4985 and for more polar are 2250 and 2750. The linear range of calibration curves was 10-500 ng/L with correlation coefficient higher than 0.9960, and the detection limit was 6.2-23.7 ng/L. Finally optimized method was applied for determination trace level of five out of six pesticides in tap and river water samples with good recovery.

Determination of polyhalogenated carbazoles in waters at low nanogram‐per‐liter concentrations with solid‐phase disk extraction

“…Furthermore, SPDE can perform direct extraction of water samples in the field, which greatly reduces the sample storage space and increases the sample stability [30]. In recent years, SPDE with different sorbent phases has been widely used in water analysis for rapid enrichment of polar and nonpolar pollutants [31][32][33][34]. C 18 disk was the preferred sorbent phase for many types of priority-controlled pollutants in environmental water [35].…”