Molecularly imprinted polymers for dispersive solid‐phase extraction of phenolic compounds in aqueous samples coupled with capillary electrophoresis

Abstract

A simple and sensitive method for the simultaneous determination of seven phenolic compounds in aqueous samples was developed by dispersive solid-phase extraction (DSPE) coupled with capillary electrophoresis (CE), namely phenol, 4-chlorophenol (4-CP), pentachlorophenol (PCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,4-dichlorophenol (2,4-DCP), 2-chlorophenol (2-CP) and 2,6-dichlorophenol (2,6-DCP). Molecularly imprinted polymers (MIPs) prepared by precipitation polymerization with 2,4,6-trichlorophenol (2,4,6-TCP) as template were used as DSPE sorbents to selectively adsorb the phenols. Various parameters affecting the extraction efficiency were evaluated and excellent CE separation was achieved within 13.5 min by using 15 mmol/L borate buffer containing 15% (v/v) methanol at pH = 9.8. Under the optimized conditions, good linearity was obtained in the range of 2-200 g/L for phenol, 2,4-DCP and 2,6-DCP, 2-300 g/L for 4-CP and 2-CP, 1.5-150 g/L for PCP, and 2-400 g/L for 2,4,6-TCP, with the correlation coefficient (R 2 ) higher than 0.9938. Limits of detection and limits of quantification were in the range of 0.18-0.44 g/L and 0.59-1.45 g/L, respectively. The developed MIPs-DSPE-CE method was also successfully applied to determine the seven phenolic compounds in lake, tap, seawater and tannery wastewater. The average recoveries at three different spiked levels ranged from 70.75 to 106.7% with the relative standard deviations of 1.15-6.28%.

Dispersive liquid–liquid microextraction of five chlorophenols in water samples followed by determination using capillary electrophoresis

“…The LOQs of our study (1.01–2.43) are lower than that of DLLME‐MEEKC (4.50–10.20) . Although our LODs and LOQs are higher than that of MIPs‐DSPE and MIPs‐SPE methods, they require synthetic materials and thereby the processes are complicated and time/reagents‐consuming . Higher EFs are obtained in DLLME‐GC and DLLME‐HPLC ; however, more organic reagents and higher analysis costs are needed than our method.…”

“…Many analytical approaches have been used for the trace‐level analysis of CPs, and CE , GC , and HPLC are of more practical interest. For GC analysis, CPs usually require to derive with suitable derivatization reagents to increase their volatility before injection into GC.…”

“…Various pretreatment and preconcentration procedures for CPs have been utilized, mainly including SPE , solid‐phase microextraction (SPME) , cloud point extraction (CPE) , liquid–liquid–liquid microextraction , and hollow fiber supported liquid–liquid–liquid membrane microextraction , dispersive liquid–liquid microextraction (DLLME) . In DLLME, the amount of extractant used is small, and the contact area between the extractant and the sample solution is maximized by the dispersant, so high enrichment factors (EFs) can be obtained.…”

“…Molecularly imprinted magnetic nanoparticle (Fe 3 O 4 @MIP)‐based extraction coupled with CE has been developed to determine trace CPs . Our group has developed dispersive solid‐phase extraction (DSPE) along with CE for CPs analysis . These studies provide higher analysis efficiency than other methods, but the preparation of molecularly imprinted polymers (MIPs) and SPE procedure is relatively labor‐intensive and time/reagents‐consuming.…”

A graphene oxide surface–molecularly imprinted polymer as a dispersive solid-phase extraction adsorbent for the determination of cefadroxil in water samples

“…Dispersive solid-phase extraction (DSPE) is based on SPE methodology, but the sorbent is added directly to the sample solution, followed by centrifugation aer extraction. 10,11 Compared with conventional SPE methods, 12 the main advantage of DSPE is the effective increase in active surface area between the analytes and sorbent. Thus, a novel molecularly imprinted polymer (MIPs) with a graphene oxide (GO)-functionalized surface was synthesized as an adsorbent for coupling with DSPE to preconcentrate cefadroxil (FAD).…”