Optimizing Determination of Trace Phthalate Esters in Groundwater by Solid Phase Extraction-Gas Chromatography

Solid phase extraction (SPE) coupled with gas chromatography was used to determine trace phthalate esters in groundwater samples. Several important experimental parameters affecting the extraction efficiency and recovery, such as the type of extraction solvent, sample volume, mass of sorbent in the SPE cartridge and elution solvent volume were studied. Results showed that 0.5 L sample, 750 mg C₁₈ sorbent and 6 mL mixed-solvent (methylene chloride and acetone) as elution solution were the best conditions for SPE. Limits of detection (LODs) of the method with standard solution were 22 ng/L ~ 341 ng/L under full scan acquisition mode. The optimized method was successfully applied to determine trace phthalate esters in the groundwater in Wuhan City, Hubei Province. DIBP, DBP and DEHP were the dominant PAEs species in groundwater samples. The concentrations of DIBP, DBP and DEHP were ranged from zero to 237.8, 1023.8 and 481.0 ng/L, respectively. DHP and DCP was occasionally detected in some samples, however, their concentrations were very low. DBP and DEHP have become broad pollutants in the groundwater of Wuhan city.