Development of magnetic multiwalled carbon nanotubes as solid‐phase extraction technique for the determination of p‐hydroxybenzoates in beverage

Abstract

In this work, magnetic multiwalled carbon nanotubes were synthesized through a facile hydrothermal process, and then successfully used as magnetic solid-phase extraction sorbents for the determination of p-hydroxybenzoates in beverage. The prepared magnetic multiwalled carbon nanotubes presented both satisfactory superparamagnetism and strong capacity of absorption, with magnetic Fe(3)O(4) beads of 200 nm average diameters decorated at either ends of the tubes. The hybrid nanocomposites showed a high efficiency in the extraction and enrichment of p-hydroxybenzoates via π-π stacking of targeted molecules onto the polyaromatic composed surface of multiwalled carbon nanotubes, which entitled them promising magnetic solid-phase extraction sorbents for p-hydroxybenzoates at trace level from complex drink samples. By using an external magnetic field, p-hydroxybenzoates adsorbed on magnetic multiwalled carbon nanotubes could be rapidly isolated in only 30 s, and subsequently analyzed by liquid chromatography-diode array detector after elution with organic solvents. Extraction conditions such as eluting solvent, the amounts of magnetic sorbents added, pH values, adsorption and desorption time were investigated and optimized to achieve the best effect. Method validations including linearity, detection limit, and precision were also studied. The linearities were in the wide range of 0.05-500 μg/mL with correlation coefficients higher than 0.9983 for all p-hydroxybenzoates. The limits of detection were less than 20 ng/mL. Acceptable RSDs were achieved within 5-8% for all analytes. The results indicated that the proposed method based on magnetic multiwalled carbon nanotubes as magnetic solid-phase extraction absorbents was rapid, efficient, and convenient for the analysis of the targeted compounds of p-hydroxybenzoates in beverage sample.

Magnetic solid-phase extraction using carbon nanotubes as sorbents: A review

“…In 2010, Morales-Cid et al [45] reported PAHs have been preconcentrated from several food samples, such as edible oils [90] and grilled meat [58], using magnetic-MWCNTs prepared by co-precipitation of iron salts and subsequent magnetite particle aggregation on the nanotube surface as the sorption material. In both cases, detection was carried out by gas chromatography mass spectrometry (GC-MS) and good LODs (0.10-0.88 and 0.035-010 ng g -1 , respectively) and acceptable inter-and intra-day precision (<9% and <13.9%) were achieved bearing Other applications of M-SPE with strategies similar to those described above have been reported for the determination of other organic compounds in environmental and food samples, including para-hydroxybenzoates [61], linear alkylbenzene sulfonates [105] (from C 10 to C 13 ) and 4-nonylphenol [106] (See Table 3 for details). can be seen from the data in Table 3 that this strategy represents the best approach to achieve the fast analysis of numerous analytes per sample with good precision and accuracy and with excellent sensitivity.…”

“…Scanning electron microscopy Morphological analysis, aggregation state [116] Transmission electron microscopy Morphological analysis of internal structure, aggregation state [46] X-ray diffraction Morphological analysis of bulk samples [55] Spectroscopic techniques Raman spectroscopy Purity, diameter distribution, functionalization [40] Infrared spectroscopy and Fourier transform infrared spectroscopy Functionalization by attaching functional groups to the sidewall [52] X-ray photoelectron spectroscopy and Energy dispersive spectroscopy Elemental composition, functionalization by attaching functional groups to the sidewall [54] Thermal techniques Thermogravimetric analysis Purity and presence of by-products, quality control of synthesis and manufacture processes [47] Magnetic techniques Vibrating sample magnetometry Magnetic properties [53] Alternating gradient magnetometry Magnetic properties [46] Superconducting quantum interference device Magnetic properties [61] M A N U S C R I P T…”

“…In addition, in the case of M-SPE, the magnetic properties of the M-CNTs can be studied and, in most of cases, this involves the use of vibrating sample magnetometry. Moreover, instruments such as the alternating gradient magnetometer[46] and superconducting quantum interference devices[61] have also been employed for the magnetic-characterization of M-CNTs. A summary of the different techniques used to characterize M-CNT composites is provided inTable 1along with the appropriate references.…”

Aminosilanized magnetic carbon microspheres for the magnetic solid‐phase extraction of bisphenol A, bisphenol AF, and tetrabromobisphenol A from environmental water samples

“…Moreover, the dispersion extraction mode can increase the overall extraction efficiency , and most magnetic adsorbents can be recycled and reused . The advantages of the rapidity, simplicity, and reduced cost, labor, and time render MSPE a prospective method for sample preparation .…”

Magnetic graphene oxide modified by imidazole‐based ionic liquids for the magnetic‐based solid‐phase extraction of polysaccharides from brown alga

“…Moreover, the efficient contact area between the sorbents and analytes increases largely due to the dispersive extraction mode, and the majority of magnetic sorbents can be recycled and reused easily . Therefore, MSPE has comprehensive advantages for simplifying the process and saving time and labor, which indicates its bright application prospect for sample preparation .…”