Multifunctionalized magnetic mesoporous silica as an efficient mixed-mode sorbent for extraction of phenoxy carboxylic acid herbicides from water samples followed by liquid chromatography-mass spectrometry in tandem

•An octyl and amino functionalized Naa kumagnetic mesoporous silica (mOAS) was prepared.•The mOAS was used as adsorbents of MSPE for selective extraction of PCAs.•PCAs could be captured through mixed-mod RP/WAX interaction mechanisms.•The proposed method was coupled with UHPLC-MS/MS.•A detection method of 8 PCAs in water samples was proposed with good performance.