Li Quanlong, Wang Xuefeng, Yuan Dongxing
State Key Laboratory of Marine Environmental Science, Environmental Science Research Center, Xiamen University, Xiamen, 361005, PR China.
J Environ Monit. 2009 Feb;11(2):439-44. doi: 10.1039/b816271a. Epub 2008 Dec 24.
The development of new sorbents, which are able to trap polar compounds, is a growing research field in solid-phase extraction (SPE). In this study, multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) were oxidized in air at 600 degrees C and 500 degrees C, respectively, for 2 h. MWCNTs, SWCNTs, air oxidized MWCNTs (OMWCNTs) and SWCNTs (OSWCNTs) (200 mg of each) were packed in SPE cartridges. The four cartridges obtained, together with a commercial Oasis HLB cartridge, were used to extract six polar organophosphorous pesticides (OPPs), i.e., dichlorvos, methamidophos, acephate, omethoate, monocrotophos and dimethoate, from an aqueous sample. The results showed that the oxidation process significantly enhanced the adsorption abilities of both SWCNTs and MWCNTs for polar OPPs. A comparative study indicated that OSWCNTs were more effective than Oasis HLB for the extraction of methamidophos and acephate and as effective as Oasis HLB for the other four OPPs from aqueous samples. When 100 mL of a natural sample was spiked with OPPs and extracted with OSWCNTs, the recoveries of five of the six polar OPPs (methamidophos excepted) ranged from 79.1 to 101.9%. The detection limits of the method based on OSWCNTs was found to be 0.07-0.12 microg L(-1).
能够捕集极性化合物的新型吸附剂的开发是固相萃取（SPE）领域中一个不断发展的研究方向。在本研究中，多壁碳纳米管（MWCNTs）和单壁碳纳米管（SWCNTs）分别在600℃和500℃的空气中氧化2小时。将MWCNTs、SWCNTs、空气氧化的MWCNTs（OMWCNTs）和SWCNTs（OSWCNTs）（各200mg）装填到SPE小柱中。所得到的这4个小柱，连同一个商用的Oasis HLB小柱，用于从水样中萃取6种极性有机磷农药（OPPs），即敌敌畏、甲胺磷、乙酰甲胺磷、氧乐果、久效磷和乐果。结果表明，氧化过程显著提高了SWCNTs和MWCNTs对极性OPPs的吸附能力。一项对比研究表明，对于水样中甲胺磷和乙酰甲胺磷的萃取，OSWCNTs比Oasis HLB更有效，而对于其他4种OPPs，OSWCNTs与Oasis HLB的效果相当。当向100mL天然样品中加入OPPs并用OSWCNTs萃取时，6种极性OPPs中的5种（除甲胺磷外）的回收率在79.1%至101.9%之间。基于OSWCNTs的该方法的检测限为0.07 - 0.12μg L⁻¹。
