Method development for the simultaneous determination of 2378‐substituted PCDD/Fs and non‐2378‐substituted TCDD in ash sample

Abstract A method was developed and validated in this study for the simultaneous determination of toxic 2378‐substituted PCDD/Fs and non‐2378‐substituted TCDD in ash samples, utilizing high‐resolution gas chromatography coupled with high‐resolution mass spectrometry (HRGC/HRMS). Selected ion monitoring (SIM) mode at a resolution of higher than 10 000‐full width at haft maximum (FWHM) (10% valley) was used for qualification and quantification of target analytes. The ash sample was pre‐treated with 1 M HCl solution and extracted with toluene using an accelerated solvent extraction technique (ASE). The extract was cleaned up on a multilayer silica gel column and an activated carbon column. The validated analytical procedure was confirmed by analysis of the ash sample in the interlaboratory proficiency test program (PT program). This method established the detection limit of PCDD/PCDF ranging from 0.1 to 1.0 ng/kg, recovery from 67% to 81%, and the relative standard deviation of replicate experiments was less than 10%. The analytical method that met the requirements for detection limit, accuracy and repeatability was applied to determine PCDD/PCDF content in some ash samples collected from copper recycling craft villages in northern Vietnam.