Determination of Dioxin in Waste Printed Circuit Boards by Accelerated Solvent Extraction and Soxhelt Extraction / 分析化学

ABSTRACT

Waste printed circuit boards(W-PCBs) were multiple smashed and separated, then passed through a 60-mesh screen, treated with hydrochloric acid (2 mol/L), ultrapure water and dehydrated with acetone successively.The filter residue and filter paper were filled into the extraction pool, or inserted into Soxhlet Extraction tube parceled with new filter paper.After addition of 5 μL of internal standard substance, the filter residue above was respectively extracted by Soxhlet Extraction (SE) method or Accelerated Solvent Extraction (ASE) method, cleaned with multi-layer silica gel column and activated-charcoal column to obtained the dioxins samples.The samples were analyzed by isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS).The effects of SE and ASE method and number of chlorines atoms on recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs were investigated, and the accuracy and precision of the two extraction methods were compared.The results show that, the recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs using ASE method is 54.3%-113.0%, and that of SE is 28.3%-77.7%, and the Toxic Equivalent Quangtity (TEQ) in W-PCBs is 0.075 ng/kg (TEQ) and 0.266 ng/kg (TEQ) using ASE and SE method respectively.Under the premise that accuracy and precision meet with the international standard, ASE is simple, rapid, solvent-free and accurate.