Simultaneous determination of polychlorinated biphenyls and polycyclic aromatic hydrocarbons in waste oils by gas chromatography- mass spectrometry- ion trapAuthor(s): Anil Narayanrao Mahindrakar, Subhash Chandra, L.P.Shinde
A capillary gas chromatographic mass spectrometry with ion trap was applied for the simultaneous determination of nine polychlorinated biphenyl (PCB) congeners and sixteen polycyclic aromatic hydrocarbons (PAHs) in waste oils (used hydraulic oils, automotive oil, machine oil, cutting oil and transformer oil). The optimized procedure involves solvent extraction using dimethyl sulfoxide (DMSO) in first step and mixture of ethyl acetate and hexane in second step. Extraction efficiencywasmonitored by using pyrened10 as surrogate standard. The separation of PCBs and PAHs was done in VF-5MS(30mx 0.25mmx0.25µm) capillary column and analysed on GC-MS using selective ion monitoring (SIM) mode. The method was calibrated using phenanthrene-d10 as an internal standard.Correlation coefficients ranged from0.9993 to 0.9999 for PCBs and 0.9941 to 0.9995 for PAHs.Recoveries of PCBs and PAHs are over 87.0 %and 70.0%respectively. The average concentration of total PAH in all waste oil samples was 1997.8 mg kg-1. The trends of the concentrations of the total PAH found in present study were machine oil > automotive oil > transformer oil > cutting oil > hydraulic oil. The average percentage of total PAH based on the ringswas 78.32%(2 ring), 8.26%(3 ring), 6.74%(4 ring), 4.80%(5 ring) and 1.56%(6 ring).