Facile synthesis of magnetic molybdenum disulfide@graphene nanocomposite with amphiphilic properties and its application in solid-phase extraction for a wide polarity of insecticides in wolfberry samples

A novel magnetic molybdenum disulfide@graphene (Fe3O4/MoS2@G) nanocomposite with amphiphilic properties was prepared by co-mixing solvothermal methods. To testify the feasibility of Fe3O4/MoS2@G as the sorbent in sample preparation, it was employed for the magnetic solid phase extraction (MSPE) of ten pyrethroids, three triazoles and two acaricide pyridaben and picoxystrobin in emulsified aqueous solution. The dichloromethane was used as extractant to form an emulsified aqueous solution. Then, the Fe3O4/MoS2@G sorbent with amphiphilic properties was used to retrieve 15 wide polarity insecticides from dichloromethane in MSPE procedures. Currently proposed method has more advantages lies in that expecting to cover different polar pesticides, strengthening the capacity of enrichment and purifying the target analytes. The π-π interaction between the hydrophilic and hydrophobicity moieties of Fe3O4/MoS2@G and the aromatic rings of the target analytes was responsible for the efficient sorption. Thus, a reliable, convenient, and efficient method for the analysis of 15 insecticides with a wide polarity in wolfberry samples was established by coupling Fe3O4/MoS2@G nanocomposite MSPE with gas chromatography-mass spectrometry (GC-MS) analysis. The obtained linearity of this method ranged from 1 to 5000 ng mL -1 for 15 analytes, with determination coefficients (R2)≥0.9907. The limits of detection (LODs) for 15 insecticides were from 0.1 to 5.0 ng g -1. The recoveries of 15 insecticides for spiked wolfberry samples were from 71.41% to 110.53%, and RSDs was less than 14.8%.