The garden plot with the composted soil was planted with maize and spinach. Throughout the cultivation phase until harvest, no further soil amendments or fertilizers were applied to the plants; instead, deionized water was utilized for irrigation. The plants (Figure ) were ready for harvesting after 40 days of development. Using a knife, each plant was carefully picked, and the different parts were combined. The plant samples were then rinsed in deionized water to get rid of any remaining dirt or dust particles. After being cleaned, the plant samples were put into black plastic bags, secured tightly, and labelled with identification information. The Multi-User Laboratory, Chemistry Department, Ahmadu Bello University, Zaria, received these samples after that to do additional analysis. The plant samples were dehydrated in an oven set to 40°C as soon as they arrived at the lab. The samples were dried, ground into a fine powder, and then placed in previously cleaned plastic bottles to be examined for heavy metals. .