Evaluation and speciation of cobalt, copper, and zinc in saline soil by microwave-assisted single extraction

摘要

The present research assessed the chemical fractionation of Cobalt (Co), Copper (Cu), and Zinc (Zn), detected in saline soil samples of Hyderabad Pakistan. The partitioning of Co, Cu, and Zn in soil samples was carried by single-step extraction using microwave irradiation energy. The validity of the methods was confirmed using the same operating conditions applied and checked as in BCR sequential extraction fractionation using certified reference material BCR-701 and the standard method of addition (recoveries 96%-102%). Atomic absorption spectrometry was used to test extractable Co, Cu, and Zn contents obtained by the comparative method. Using compromised microwave conditions steps 1-3 of the sequential extraction (excluding hydrogen peroxide digestion in step 3) could be accomplished with an ultrasonic bath between 15 and 30 min, whereas 60-120 s were needed for microwave single-extraction (MSE). The total concentrations of Co, Cu, and Zn extractable metals produced by three separate extractions ranged from 1.02-3.30, 5.02-9.95, and 3.97-8.01 μg/g respectively. Consequently, the use of single-step extraction with the aid of microwave and ultrasound energy to reduce the time required for single-step extraction based on the BCR sequential extraction method. However, with the aid of developed single-step extraction methods, the obtained results were comparable to those values obtained from BCR sequential extraction method. For further study, the MSE can be frequently used to know the metal-bound intensity with a different chemical fraction on environmental solid samples.