Solid-phase microextraction using octadecyl-bonded silica immobilized on the surface of a rotating disk: Determination of hexachlorobenzene in water

• Published in: Analytica chimica acta Vol. 743; pp. 75 - 79
• Main Authors: Cañas, Alejandro, Richter, Pablo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 19.09.2012; Elsevier
• Subjects: Analytical chemistry; C18; Chemistry; Exact sciences and technology; Hexachlorobenzene; Microextraction; Pesticide; Polydimethylsiloxane; Rotating disk; Microextraction; C18; Pesticide; Polydimethylsiloxane; Hexachlorobenzene; Rotating disk; Performance evaluation; C; Immobilization; Time; Silica; Chemical enrichment; Accuracy; Sample preparation; Detection limit; Extraction; Diffusion; Solvent; Elution; Sample; Use; Pesticides; Method; Tap water; Solid phase microextraction; Sorption; Volume; Dichloromethane; Transfer
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2012.07.019

[Display omitted] ► We implemented a C18 sorptive phase on a rotating disk for microextraction of pollutants. ► The rotating disk can be stirred at high velocities without damaging the phase. ► The disk configuration is easily fabricated in the laboratory. ► The equilibrium time achieved in C18 is similar than in PDMS. ► The analyte elution in C18 was faster than in PDMS. Solid-phase microextraction of hexachlorobenzene from water was implemented for the first time on a rotating disk coated with an octadecyl-bonded silica (C18) sorptive phase. The results indicate that the sorption performance of this phase for the model analyte selected is similar to that observed using a rotating disk containing PDMS. In both cases, equilibrium is achieved within approximately 120min for samples volumes of 50mL and decreases to 20–30min when the sample volume is decreased to 10mL. The comparable behavior observed for the sorption of HCB in both phases is consistent with a similar rate-determining step for extraction, which suggests that the overall mass transfer of analyte is not limited by internal diffusion into the phase but by diffusion into the aqueous stagnant layer. The main advantage in the use of the C18 phase is that the elution of the analyte was achieved in 15min compared with 45min for PDMS because, in the case of C18, dichloromethane can be used as the eluting solvent. The detection limit of the method was 0.08μgL−1 HCB for a tap-water sample. The mean recovery for the analyte was 84±2% and 85±3% for the C18 and PDMS phases, respectively, which indicates good accuracy and precision of the method.