RETRACTED: Rapid and effective sample cleanup based on graphene oxide-encapsulated core–shell magnetic microspheres for determination of fifteen trace environmental phenols in seafood by liquid chromatography–tandem mass spectrometry
Authors: Mi-Cong Jin
Hao-Yu Shen
Xiao-Hong Chen
Sheng-Dong Pan
Mei-Qiang Cai
Xiao-Ping Li
Yong-Gang Zhao
Journal: Analytica Chimica Acta (2016)
Discipline: CHEMISTRY
Keywords: Cleanup mechanisms; Environmental phenols; Graphene oxide-encapsulated core–shell magnetic microspheres; Magnetic solid-phase extraction; Seafood samples.
Affiliations: Key Laboratory of Health Risk Appraisal for Trace Toxic Chemicals of Zhejiang Province, Ningbo Municipal Center for Disease Control and Prevention, Ningbo, Zhejiang 315010, China; Ningbo Key Laboratory of Poison Research and Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China., Ningbo Institute of Technology, Zhejiang University, Ningbo, Zhejiang 315100, China., School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China., Key Laboratory of Health Risk Appraisal for Trace Toxic Chemicals of Zhejiang Province, Ningbo Municipal Center for Disease Control and Prevention, Ningbo, Zhejiang 315010, China; Ningbo Key Laboratory of Poison Research and Control, Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, China. Electronic address: .

Abstract:  In this study, graphene oxide-encapsulated core-shell magnetic microspheres (GOE-CS-MM) were fabricated by a self-assemble approach between positive charged poly(diallyldimethylammonium) chloride (PDDA)-modified Fe3O4@SiO2 and negative charged GO sheets via electrostatic interaction. The as-prepared GOE-CS-MM was carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer analysis (VSM), and X-ray photoelectron spectroscopy (XPS), and was used as a cleanup adsorbent in magnetic solid-phase extraction (MSPE) for determination of 15 trace-level environmental phenols in seafood coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). The obtained results showed that the GOE-CS-MM exhibited excellent cleanup efficiency and could availably reduce the matrix effect. The cleanup mechanisms were investigated and referred to π-π stacking interaction and hydrogen bond between GOE-CS-MM and impurities in the extracts. Moreover, the extraction and cleanup conditions of GOE-CS-MM toward phenols were optimized in detail. Under the optimized conditions, the limits of detection (LODs) were found to be 0.003-0.06 μg kg(-1), and satisfactory recovery values of 84.8-103.1% were obtained for the tested seafood samples. It was confirmed that the developed method is simple, fast, sensitive, and accurate for the determination of 15 trace environmental phenols in seafood samples. 

Retracted: Yes

PubPeer comments:
  Fig. 4. SEM images of (c) Fe3O4@SiO2 The three microspheres all show similar features, as if they were rotated versions of a single image. ![file] See also Fig 3(f) ( core-shell MD-CS-MMIP ) in [another paper by the same authors] : ![] UPDATE: I am inclined to believe that the original appearance of the  nipple nanosphere was  Fig. 1. SEM images of ... (b) GO-Fe3O4 , from [Pan et al. (2014)] . ![file] , 
  Fig. 7. Fluorescence spectra of GOE-CS-MM adsorbed with different amounts of astaxanthin . ![] Please compare with  Fig. 8 ...(c) fluorescence spectra of T-MMIP adsorbed with different amounts of MCs (initial MCs concentrations of 0, 1.0 mg L1, 2.0 mg L1, 5.0 mg L1 and 10 mg L1, respectively) from [Pan et al. (2015)] (here shown at upper right): ![file] Please also compare with Top left:  5 ... (c) fluorescence spectroscopy of: (i) GO-Fe3O4@P (ii~v) GO-Fe3O4@P adsorbed with different amount of 2,4,6-TCP (initial 2,4,6-TCP concentrations at 10 mg L, 100 mg L, 200 mg L, and 500 mg L, respectively) from [Chen et al (2014)] and Top right:  Fig. 5 ... (f) fluorescence spectra of (1) MGO@MIP, (2) PCP, (3)u2013(6) MGO@MIP adsorbed with different amounts of PCP (initial PCP concentrations of 10 mg L1, 100 mg L1, 500 mg L1, and 800 mg L1, respectively) , from [Pan et al. (2014)] . ![] Those two families of spectra are remarkably similar, after a horizontal flip. Superimposed at lower right. , 
 Twitter points to the following RETRACTION NOTICE: https: www.sciencedirect.com science article pii S0003267016302719?via%3Dihub , 
 #3 This article has been retracted at the request of the Editor after the corresponding author pointed the Editor to comments from an anonymous reader. The article reports electron micrographs of different preparations while showing identical images as used in previous publications by the same authors. The particles in Figure 4C (SEM image of Fe3O4@SiO2) are identical to each other and the corresponding author confirmed that these have been copy-pasted. In addition, these particles have previously been communicated as different substances in Figure 1B from Pan et al., J. Mater. Chem. A, 2015,3, 23042-23052 (DOI: 10.1039 C5TA05840F) and Figure 3F from Pan et al., Anal. Methods, 2017,9, 5281-5292 (DOI: 10.1039 C7AY01444A). Furthermore, the curves in Figure 7, especially the baseline, shows a remarkable similarity to Fig. 8 from Pan et al., J. Mater. Chem. A, 2015,3, 23042-23052 (DOI: 10.1039 C5TA05840F) and Fig. 5F from Pan et al., J. Mater. Chem. A, 2014,2, 15345-15356 (DOI: 10.1039 c4ta02600d). The manipulation of images and data in this way is a serious offense to the integrity of the scientific community and casts doubts on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. ,