Polymer monolithic column containing embedded graphene oxide sheets for sensitive determination of carbamate insecticides by HPLC

Abstract

We describe a new kind of polymer monolithic column for polymer monolith microextraction (PMME) of carbamate insecticide (methomyl, carbofuran and pirimicarb) residues from water samples. The monolith was prepared inside the tip of a micropipette via thermally initiated free-radical polymerization of methacrylic acid as the monomer, ethylene glycol dimethacrylate as the crosslinker, and graphene oxide (GO) dispersed in the mixed porogens (1-propanol and 1,4-butanediol). The resulting monolith was characterized by scanning electron microscopy and IR spectrometry. The effects of sample flow rate, sample volume, sample pH, desorption solvent and flow rate on PMME were optimized. Compared to a monolith without GO, the new monolith displays higher enrichment capacity, and is reusable and stable. Following extraction, the three carbamates were quantified by HPLC. The limits of detection (for S/N=3) for the three carbamates are in the range of 0.3-0.7 μg L −1 , and the intra-and inter-day precisions are <5.7 %. The new monolith was successfully applied for the determination of the insecticides in various (spiked) environmental water samples, with recoveries in the range from 78.9 to 103.4 %.

Fabrication of boron‐rich multiple monolithic fibers for the solid‐phase microextraction of carbamate pesticide residues in complex samples

“…Besides, the sensitivity obtained in this work is better than that obtained by other methods with the same kind of detector . It also can be seen from the comparison that the recoveries obtained in the present study are comparable with other mentioned methods . The comparison well demonstrates the proposed VPED/MMF‐SPME‐HPLC‐DAD method possesses some merits such as convenient operation, satisfactory sensitivity and eco‐friendliness, in the analysis of CPs.…”

“…However, the LODs achieved in the present method are lower than that achieved on SPE-HPLC-MS/MS [27] and LLME-MEKC-MS/MS [33]. Besides, the sensitivity obtained in this work is better than that obtained by other methods with the same kind of detector [21][22][23][24][28][29][30][31][32]. It also can be seen from the comparison that the recoveries obtained in the present study are comparable with other mentioned methods [21][22][23][24][25][26][27][28][29][30][31][32][33].…”

“…As shown, the consumption of organic solvent in the proposed method is at the same level as that used in micro-SPE (μ-SPE)-HPLC-UV [21], stir bar sorptive extraction-HPLC-UV [22], ultrasound-assisted surfactant enhanced mulsification microextraction-HPLC-UV [23], and less than other methods [24][25][26][27][28][29][30][31][32][33]. The consumed sample volume in the proposed method is slightly higher than that used it some reported methods [21][22][23][24]27,29,30,32,33], but far lower than that consumed in SPE-HPLC-MS/MS [25], SPE-HPLC-MS [26] and SPE-HPLC-UV [3]. Typically, for the determination of CPs, better sensitivity can be achieved when high sensitivity detector such as MS is used [25,26].…”

Solid-phase extraction of phytosterols from rapeseed oil deodorizer distillates with magnetic graphene oxide nanocomposite

“…Cui et al (2018) developed a composite monolith based on GO to determine ß-sitosterol in food samples. In the same vein, GO sheets were embedded in polymer monolithic columns by Jin et al [29] to determine carbamate insecticides through HPLC analysis. Also, magnetic graphene nanocomposite was considered as an adsorbent for the extraction of vitamin D2 and vitamin D3 from milk samples [30].…”