Laser-induced breakdown spectroscopy (LIBS) has emerged as a potent device for studying the interaction of laser beams with materials and has gained significant interest in recent years. This technique allows for fast and contactless analysis of almost any type of material, making it highly versatile and adaptable to diverse analytical problems. Fruits are one of the most commonly produced agricultural products, resulting high level of waste from the juice processing industry. The outer layer of the fruit peel is used in a variety of commercial applications such as food, soft drinks, candy flavors, and as a biomass energy source and adsorbent material. In this study, we observed Carbon (C), Iron (Fe), Magnesium (Mg), Vanadium (V), Calcium (Ca) and Lead (Pb) as trace elements in all samples. We analyzed the data of some emission lines such as C-I (193.09 nm), Mg-II (279.55 nm), Fe-II (229.28 nm), and Mg-II (280.27 nm). Additionally,  we have determined the density of electrons in the orange peel sample which is varied from 4.45×10¹⁷ cm^-3 to 5.90×10¹⁷ cm^-3 with an energy variant from 80 mJ to 190 mJ. However, it is well-known that the value of electron number density (N_e) in the surrounding area of the target sample was at a minimum and increased with increasing energy. We estimated the weight percentage of each element present in the orange sample peel using the CF-LIBS method and found that iron (Fe) has the highest concentration.

Keywords: Laser-induced breakdown spectroscopy (LIBS), analytical problems, CF-LIBS method