ASSESSMENT OF FLUORIDE AND HEAVY METAL LEVELS IN SELECTED TOOTHPASTE BRANDS IN NIGERIA

This study investigated the fluoride concentration, moisture content, pH, and heavy metal composition of selected toothpaste brands available in the Nigerian market, comprising seven locally manufactured and seven imported brands. A total of fourteen samples were analyzed to determine fluoride levels using Ultraviolet-Visible spectrophotometry (Jenway 7310) and heavy metal concentrations (Zn, Mn, Cu, Fe, Cd, Pb, Cr) using Atomic Absorption Spectrophotometry (Buck 235). Moisture content and pH were determined by standard gravimetric and potentiometric methods, respectively. The results showed that fluoride concentrations ranged from 1212.50 mg/kg (S12) to 1787.50 mg/kg (S7). While most adult formulations fell within the WHO-recommended range for adult toothpaste (1000–1500 mg/kg), several pediatric formulations exceeded the 1000 mg/kg limit for children’s toothpaste. Moisture content varied from 29.87% (S11) to 70.49% (S7), with higher values observed in gel-based and pediatric formulations. The pH of the samples ranged from 6.30 (S12) to 7.99 (S1), with most samples falling within the neutral to slightly alkaline range considered safe for oral use. Heavy metal analysis revealed that cadmium (Cd) and lead (Pb) were not detected in any sample. Zinc (Zn) concentrations ranged from 0.28 mg/kg (S5) to 10.34 mg/kg (S1), with three brands showing relatively high Zn levels. Copper (Cu) was detected in all samples, with values between 0.24 mg/kg (S9) and 3.02 mg/kg (S1). Iron (Fe) levels ranged from 1.94 mg/kg (S1) to 6.29 mg/kg (S7), and chromium (Cr) ranged from 0.12 mg/kg (S1) to 1.41 mg/kg (S14). Manganese (Mn) was detected only in S7 at 0.22 mg/kg.