Using Graphene And Its Composite As Spe Materials For Determination Of Residues In Aquatic Products

Graphene is a monolayer of carbon atoms densely packed into a two-dimensional honeycomb crystal lattice. Graphene has a large surface area and special π-π structure, which makes it possible to be a superior solid phase extraction (SPE) sorbent for purification of complex sample matrix. A series of problems have happened in aquatic products industry in recent years due to the environment pollution and drug abuse. The problem of residues in aquatic products has already become export restriction factor. At the same time, a large number of pesticide and veterinary drug abuse would seriously harm to human health. Therefore, a rapid, sensitive and highly selective method for determination of residues in fish tissues is required. In this study, the methods for determination of sulfonamides (SAs) and carbamates in fish products were developed. Samples were enriched by SPE using graphene as sorbent and quantified by ultra-high-performance liquid chromatography coupled with electro-spray ionization tandem mass spectrometry.1. The methods of the synthesis of graphite oxide (GO), graphene and platinum-graphene (Pt-G) were discussed. The synthetic graphene and its composite were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), fourier transform infrared spectroscopy (FTIR) and energy dispersive X-Ray spectroscopy (EDX). The characterization results demonstrate that graphene and its composite have been successfully prepared and can be applied to SPE procedures.2. A sensitive method for simultaneous determination of13SAs using graphene-based solid phase extraction coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. Graphene was used as SPE material and SPE parameters were optimized. The recovery of SAs extracted by graphene-based SPE was higher compared with other traditional materials at the same optimized condition. The matrix effect experiment illustrated the advantages of graphene as purified material. Method validation proved the feasibility of the developed nanoparticles for the quantitation of the investigated analytes at trace levels obtaining lower limit of detection values in the0.034～0.268μg/kg range. Average recoveries of individual sulfonamide were between76.2to94.7%. A good precision with coefficients of variations always lower than6.8%was obtained. This work not only proposes a useful method for fish sample pretreatment, but also reveals great potentials of graphene as an excellent sorbent material in analytical processes.3. The method of rapid determination of10carbamate pesticides in fish using Pt-G-based SPE coupled with UPLC-MS/MS was developed. Pt-G was used as SPE sorbent. The method using matrix-matched calibration as working calibration and the estimated LODs and LOQs were in the low μg/kg level varied from0.074～0.416μg/kg and0.247～1.386μg/kg, respectively. It was proved that samples purified by Pt-G could meet the detection requirement of mass spectrometry through matrix effect study. At the same time, the method also greatly shortened the time and reduced the dosage of organic reagents. This proposed method has successfully revealed the great potentials of Pt-G as an excellent SPE sorbent, and can be applicable to determine other analytes in foodstuffs.