A Comparative Study on Mineral Contents of Soybean by Two Methods of Digestion Using ICP-OES Technique: A Risk Assessment Study

In recent years, the contamination of food with heavy metals has received much attention. Plants can absorb metal pollutants through contaminated water, soil, and air.

In the current study, accumulation of minerals in three types of soybeans was investigated by wet and dry digestion methods using ICP-OES technique. Thereafter, the metals' health risk was assessed by estimated daily intake, toxic hazard quotient (THQ), and hazard index (HI) values.

According to the results, the concentrations of Cr, Se, Ca, Fe, Mo, Mn, and Mg in soybean seeds were 0.034-170.88 mg/kg, 0.21-243.79 mg//kg, 2.50-33.37 mg/kg, 0.05-0.86 mg/kg, 0.071-203.57 mg/kg, 0-0.47 mg/kg, and 2.69-19.31 mg/kg, respectively. The ashing method had a better performance in determining Ca, Fe, Mo, Mn, and Mg concentrations than the wet digestion method. The THQ rates were below 1 for the three varieties of each mineral element, but the HI values of variety 2 and variety 3 were higher than 1 in both methods.

Furthermore, continuous monitoring of the soybeans' mineral and heavy metal contents seems necessary.