Release Time:2019-07-01  Hits:

Indexed by: Journal Article

Date of Publication: 2019-08-15

Journal: FOOD CHEMISTRY

Included Journals: EI、SCIE、PubMed

Volume: 289

Page Number: 701-707

ISSN: 0308-8146

Key Words: Magnetic solid phase extraction; High resolution mass spectrometry; Sulfonamides; Sample preparation; Carbon nanotubes

Abstract: A simple modification method was developed for the functionalization of amino terminated carbon nanotubes (CNT-NH2) by using isocyanates as modifiers via the nucleophilic addition reaction. Two types of functionalized magnetic carbon nanotubes (MCNT) were prepared through deposition of magnetic nanoparticles on CNT-NH2 and modification with different isocyanates. p-Tolyl-functionalized MCNT (Tol-MCNT) with better adsorption performance were selected as adsorbent for magnetic solid phase extraction (MSPE), which could extract sulfonamides (SAs) from various milk samples with a enrichment factor of about 30 after optimization. By combining the MSPE with liquid chromatography-high resolution mass spectrometry (LC-HRMS), a new method was developed. Both skimmed and whole milk samples of three brands were analyzed with this method, and 4 SAs including sulfadiazine, sulfisomidine, sulfamethazine and sulfameter were detected with the concentration from unquantifiable to 72 ng/L, which were all well below the maximum residue limits in milk according to the regulations of China and EU.