In this work, the development of a "green" sample preparation procedure for the analysis of inorganic fertilizers based on ultrasound-assisted extraction using an ultrasonic bath is described. Samples (70 mg) were sonicated for 5 min in the presence of 2 mL of 50% (v/v) HNO3 inside glass tubes. The determination of copper, lead and cadmium in the extracts were carried out by flame atomic absorption spectrometry (FAAS). It is also demonstrated the possibility of using of a vortex shaker as a mechanical agitation source to perform the metal extraction. The proposed extraction procedure using an ultrasonic bath or a vortex shaker is simple and versatile, and minimizes waste generation due to the employment of reduced volumes of acid and sample, contributing for the development of a clean analytical method.
fertilizer; ultrasound; vortex; metals; extraction
