Solid phase extraction to enhance sensitivity when headspace-gas chromatography-ion mobility spectrometer is used: determination of phenol in environmental samples

Abstract

Ion mobility spectrometry (IMS) provides quick and reliable responses when applied in the environmental field. However, when headspace (HS) is used as the sample introduction system, in some cases there may be a need to preconcentrate analyte if it is presented at low concentrations due to the low efficiency of HS. Herein, we discuss the parameters that affect the HS and the potential of combining solid phase extraction (SPE) and HS-IMS to improve the sensitivity of the method. The determination of phenol when it is presented in water or soil samples was selected as a case study and a limit of detection of 0.94 μg mL⁻¹ and 0.14 μg mL⁻¹ was obtained when direct analysis by HS-IMS was used. This methodology, which was developed based on SPE prior to HS-IMS analysis, was suitable for the detection of phenol at 0.05 μg mL⁻¹ when 15 mL of water sample was passed through an HLB 60 mg SPE cartridge and eluted with 1 mL of dichloromethane. The HS-IMS analysis of the eluent in which phenol was present was carried out without any interference from the solvent.