In situ-floating organic dispersive solid-phase extraction based on putrescine as a new adsorbent for the extraction of ions from crude oil prior to ICP-MS

Abstract

ABSTRACT Quantification of ions in complex matrices like crude oil is an outstanding issue because of the high complexity of the sample. Herein, a facile, reliable, and precise floating dispersive solid-phase extraction procedure was introduced for the extraction of several ions (B, Ca, Cd, Cu, Cr, Ag, Fe, Mn, Ni, Na, Ba, Mg, Al, Si, Sn, Ti, Mo, V, Pb, Zn, P, and K) in which the need for adding complexing agent for the extraction of ions, centrifugation for separation of adsorbent, and shaker to enhance the contact area of the sample solution with absorbent was eliminated. These advantages were provided by using putrescine as the absorbent for the extraction of the analytes. To reach this goal, a proper amount of putrescine was dissolved in ethanol and injected into a diluted crude oil solution. During this step, putrescine formed stable complexes with the ions and extracted them from the solution and collected on top of the solution easily. The floated phase was collected by a spatula, and the extracted ions were determined by inductively coupled plasma mass spectrometry. Validation parameters of this method showed that low limits of detection (0.003–3.62 ng g−1) and quantification (0.009–12.0 ng g−1), broad linear range (12.0–80,000 ng g−1), acceptable relative standard deviation (≤5.3%) for intra- and inter-day precisions and high extraction recovery (72–90%) were the features of the method. The method was successful in the determination of the analytes in real crude oil samples.