Study On The Solid-Phase Extraction For Water POPs By Two Kinds Of New Materials

Solid-phase extraction (SPE)is the most common technique for environmentalwater sample pretreatment. Various types of solid-phase extraction sorbents includingC18\C8 silica, polar LC-CN, and LC-NH₂ have been used. Gas chromatography(GC) the highly sensi tive electron-capture detection (ECD) is an importantanalytical technique to determination the pesticides residues in environmentalwaters. In this study, the applicability of multiwalled carbon nanotubes(MWNTs) andActive Carbon-Calcium hydroxide(ACCH) as packing adsorbents was investigated toextract Organochlorine Pesticides (OCPs)and polychlorinated biphenyl(PCBs) inwater.Due to larger internal surface, We can learn that MWNTs have very strongadsorption to dioxin removal. The accuracy of the proposed method was tested byrecovery measurements on spiked samples, and good recoveries results 61.5～138.8%were obtained. And the relative standard deviation was from11.9 to 22.6%. Thedetection limit of this method is range from0.156 ng/mL to 0.487ng/mL for differentOCPs and PCBs..The adsorptive potential of ACCH for solid-phase extraction of OCPs and PCBs inwater was investigated for the first time. The accuracy of the proposed method wastested by recovery measurements on spiked samples, and good recoveries results45.9～109.3%were obtained compared with liquid-liquid extraction method. And therelative standard deviation was from 0.053 to 0.255 (%). The detection limit of thismethod is range from 0.053ng/mL to 0.255 ng/mL for different OCPs and PCBs.Parameters influencing the extraction efficiency, such as volume of the samplesolution, pH of the sample, solid-phase extraction adsorbent amount and the eluentsolution and eluent volume were examined. Comparative studies showed that MWNTsand ACCH were at least as effective as C₁₈silica SPE cartridge and Liquid-liquidextraction (LLE) to mostly inerest compound in water.