Table 1. Weight Percentages of Elements Present in Sugarcane Waste Ash and Silica Nanoparticle Samples Determined by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP–OES).

elements	SWA (wt %)	SiO2NPs (wt %)
aSiO2	88.68	99.08
Al2O3	1.026	0.997
Fe2O3	1.688	0.363
TiO2	0.686	0.063
(PO4)3–	0.013	0.013
NiO	0.012	0.012
CaO	0.117
K	0.262
MgO	0.288
MnO	0.021
Na	0.013

^aSiO₂ was determined by gravimetric analyses. Only metals and oxide metals were determined. The analytical technique has 1.0% of error.