Determination of pentachlorophenol and its sodium salt residue in eggs using d -SPE method coupled with UPLC-MS/MS

A method, improved d-SPE extration couple with ultra performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS), was developed for the determination of pentachlorophenol and its sodium salt residue in eggs. The sodium pentachlorophenol in the eggs was converted firstly into pentachlorophenol under acidic conditions, extracted by 1.5% (v/v) acetic acid/acetonitril, and the extraction solution was purified finally by disperse solid phase extraction. The composition of dispersive sorbents was optimized based on the recoveries and matrix effects. The recoveries at fortification levels of 0.5, 5 and 50.0 μg/kg in eggs ranged from 72.2% to 89.8% with the relative standard deviations of 0.2%~0.8%. The limits of quantification (LOQ) was 0.5 μg/kg. Market samples were quantified, and PCP residues were found, but all the detection levels were below the method LOQ. We demonstrated that UPLC – MS/MS in combination with modified d-SPE can be used to routinely monitor PCP residues in egg samples.