Determination of trace leaching phthalate esters in water by magnetic solid phase extraction based on magnetic multi-walled carbon nanotubes followed by GC-MS/MS

A magnetic solid phase extraction method coupled to gas chromatography-tandem mass spectrometry was proposed for the determination of phthalate esters at trace levels in drinking water. The magnetic multi-walled carbon nanotubes were prepared and applied as sorbents for magnetic solid phase extraction. The major factors affecting the recovery efficiency, such as the amount of magnetic multi-walled carbon nanotubes, pH of the water sample, desorption conditions and extracting time were carefully investigated. The recovery of these compounds was in the range of 86.6-100.2% with a relative standard deviation (RSD) value of less than 10%. Good linearities (r > 0.9993) were obtained. The limits of detection for phthalate esters were in the range of 0.009-0.032 mu g L-1. The results show that the developed method is suitable for the monitoring of trace phthalate esters in drinking water samples.