Js. Yang et al., Effect of solvent on extraction of polychlorinated biphenyls and polychlorinated dibenzodioxins from charcoal, J LIQ CHR R, 24(15), 2001, pp. 2293-2302
The effect of solvent on the extraction of two polychlorinated biphenyls (P
CBs) and five polychlorinated dibenzodioxins (PCDDs) from charcoal is inves
tigated and the variations in recoveries of these analytes are explained. T
he extraction is performed using chromatographic elution, ultrasound-assist
ed extraction (UAE) of probe- and bath-type, supercritical fluid extraction
(SFE), and enhanced-fluidity liquid extraction (EFLE). In each of the extr
action methods used, only the use of isopropanol-toluene mixtures shows hig
her recoveries than the use of toluene alone.
Higher recoveries are obtained using EFLE, compared with other extraction m
ethods, even though the same amount, i.e., 30mL, of extraction solvent is u
sed, because higher temperature is applied under higher pressure. After eac
h extraction, chromatographic interferences are removed through a multilaye
r silica gel column clean-up. The quantification of PCBs and PCDDs is perfo
rmed using HPLC-UV.