Analytical Method Of Dioxin In Serum By High Resolution Gas Chromatography-high Resolution Mass Spectrometry

Objective: To establish a high sensitivity and high throughput detection method ofdioxin， through comparison of different analytical methods of dioxin in serum.Method: Six pretreatment methods were compared, including Soxhletextraction-FMS(Fluid Management Systems) cleanup method, ASE(AcceleratedSolvent Extraction)-FMS cleanup method, H2SO4-Hexane-FMS cleanup method,(NH4)2SO4-Ethanol-Hexane-FMS cleanup method, C18SPE(Solid Phase Extraction)-FMS cleanup method, C18SPE-SPE cleanup method. After pretreatment, sampleswere detected by HRGC-HRMS (High Resolution Gas Chromatography-HighResolution Mass Spectrometry) with a PTV injector using an isotope-dilution method.The results of quantitative internal standard recoveries, matrix standard additionrecoveries and method blank were compared and the best method was chosen.Results: ASE-FMS cleanup method was selected as the optimum pretreatment method.The concentration range was0.5ng/mL-200ng/mL,2.5ng/mL-1000ng/mL and5ng/mL-2000ng/mL for TCDD/Fs, PeCDD/Fs-HpCDD/Fs and OCDD/Fs seperately,with the limits of detections of0.01pg/mL-0.06pg/mL. The quantitative internalstandard recovery was at38.0%-84.3%with the matrix standard addition recovery at84.1%-96.6%. No blank values were detected except1234678-HpCDD and OCDD.The optimum experimental conditions were as follows:2mL serum was freeze-driedand extracted by Hexane:Dichloromethane(1:1). Then, the solution was concentratedand cleaned by Fluid Management Systems through silica, aluminam and carboncolumns. Finally, the solution was concentrated to20μL and detected byHRGC-HRMS with the injection volume of10μL through the PTV injector. Theinjection of PTV increased the sample volume and improved the sensitivity of themethod.Conclusion: ASE-FMS cleanup method was chosen as the best pretreatment methodand PTV-HRGC-HRMS with isotope-dilution method was used to detect the sample. Because of the simplicity, high recovery rates and sensitivity of this method, it can beused to determine the concentration of dioxin in human serum.