A new solid-phase extraction disk based on a sheet of single-walled carbon nanotubes

Abstract

A new kind of solid-phase extraction disk based on a sheet of single-walled carbon nanotubes (SWCNTs) is developed in this study. The properties of such disks are tested, and different disks showed satisfactory reproducibility. One liter of aqueous solution can pass through the disk within 10-100 min while still allowing good recoveries. Two disks (DD-disk) can be stacked to enrich phthalate esters, bisphenol A (BPA), 4-n-nonylphenol (4-NP), 4-tert-octylphenol (4-OP) and chlorophenols from various volumes of solution. The results show that SWCNT disks have high extraction ability for all analytes. The SWCNT disk can extract polar chlorophenols more efficiently than a C 18 disk from water solution. Unlike the activated carbon disk, analytes adsorbed by the new disks can be eluted completely with 8-15 mL of methanol or acetonitrile. Finally, the DD-disk system is used to pretreat 1000-mL real-world water samples spiked with BPA, 4-OP and 4-NP. Detection limits of 7, 25, and 38 ng L −1 for BPA, 4-OP, and 4-NP, respectively, were achieved under optimized conditions. The advantages of this new disk include its strong adsorption ability, its high flow rate and its easy preparation.

Surfactant-modified flowerlike layered double hydroxide-coated magnetic nanoparticles for preconcentration of phthalate esters from environmental water samples

“…Recently, due to their large adsorption area and high speed of equilibrium, nanomaterials have attracted attention for preconcentration [1][2][3]. However, there are several limitations, such as large backpressure and long sample loading time when they are packed into cartridges.…”

Occurrence of residual water within disk-based solid-phase extraction and its effect on GC-MS measurement of organic extracts of environmental samples

“…Therefore, it is not surprising that the needed gas volume for the drying process depends on the used SPE disk types in addition to the volume flow. For a drying time of 30 min, the total gas volume for the Varian SPEC C 18 SPE disk amounts to 102 L and for Bakerbond Speedisk Extraction Disk C 18 only to 56 L. In practice, the needed gas volumes are considerably smaller, because the drying time amounts only to a few minutes (3-7 min [17,[29][30][31][32][33][34][35]) in most published methods.…”

Nanomaterial and their applications in Environmental sample preparation techniques: A Review

“…Since then, different types of CNTs, including non-functionalized or modified MWCNTs, and SWCNTs, were used as packing materials for preconcentration of phenolic compounds, pesticides, pharmaceuticals, inorganic ions and organometallic compounds in food, in environmental samples, or in biofluids, which were summarized in the review papers 33,34 . The excellent features of CNTs make them ideal sorbents in different microconcentrators or micro-sorbent traps, which were reviewed by Hussain and Mitra…”

“…The fiber materials used in CNTs-SPME can be fused silica, hollow fiber, stainless steel, gold or platinum wire to acquire special properties 29,33,34 . After oxidation under extreme conditions, CNTs possess hydroxyl, carboxyl and carbonyl groups on their surface and show exceptional adsorption efficiency for metal removal when the solution pH is higher than the isoelectric point of the oxidized CNTs.…”