Highly Sensitive Detection Method of Dibenzyl Disulfide in Insulating Oil

Highly sensitive detection method of dibenzyl disulfide (DBDS) in insulation oil was realized using solid phase microextraction (SPME) with, MWCNT/ PANI nanocomposite coating adsorbent followed by gas chromatography equipped with a ECD spectrometry (GC-ECD). An aniline-based polymer was electrochemically prepared and applied as a new fiber coating for solid phase microextraction (SPME) of of dibenzyl disulfide (DBDS) in insulation oil. The polyaniline (PANI) film was directly electrodeposited on the platinum wire surface in sulfuric acid solution using cyclic voltammetry (CV) technique[1]. The efficiency of new coating was investigated using a laboratory-made SPME device and gas chromatography with electron capture detection for the extraction of dibenzyl disulfide from oil samples. The scanning electron microscopy (SEM) images showed the homogeneity and the porous surface structure of the film. The results obtained proved the ability of this polymer as a suitable SPME fiber coating for trapping the dibenzyl disulfide. The parameters effective On SPME of DBDS (i.e., extraction temperature, extraction time, desorption temperature, desorption time, salt concentration, and stirring rate) were investigated and optimized by one-variable-at-a-time method. Under optimized conditions (extraction temperature, 55 ± 1 °C; extraction time, 35 min; desorption temperature, 260 °C; ; salt concentration, 10% w/v; and stirring rate, 1200 rpm), the limits of detection (LODs) were found in the range of 0.001-0.1 μg L-1, acceptable linear range with correlation coefficients ranging from 0.9878 , the repeatability and fiber-to-fiber reproducibility were in the range 4.7% and 9.4%, respectively.