Keggin-type heteropoly compounds supported on montmorillonite clays offering strong option for efficient solid-phase microextraction coating

Keggin-type heteropoly compounds supported on montmorillonite clays were prepared and used as a highly porous fiber coating material for solid-phase microextraction (SPME). The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample solutions in combination with gas chromatography–mass spectrometry (GC–MS). A one at-the-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time. In optimum conditions, the repeatability for one fiber (n = 3), expressed as relative standard deviation (R.S.D.%), was between 5.1% and 8.4% for the test compounds. The detection limits for the studied compounds were between 0.02 and 0.05 pg mL−1. The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber, and high relative recovery in comparison to conventional methods of analysis.