“…In order to seek more effective, environmental friendly, and economic enrichment materials for the application of on-line SPE analysis, many scholars pay attention on the development of new materials, including amino column [65] , hydrosulfonyl column [66] , copper isonicotinate coordination polymer [67] , -cyclodextrin silica gel [68] , polymer columns [69,70] , immunoaffinity column [71,72] , expanded graphite [73] , multi-walled carbon nanotube [74] , and some application even use cotton [75] and cigarette filter [76,77] for on-line adsorption of organic pollutants and perfect results could be obtained. The properties of these new adsorbents are low cost, easy producibility, some of which can be used repeatedly.…”