Overview
Sani and colleagues bought four chocolate brands in Hadejia, dried and digested them, and measured lead, cadmium, chromium and nickel by flame atomic absorption. Table 1 reports one value per brand and metal, labeled in mg/g. The authors conclude that all samples exceed WHO values for lead, cadmium and chromium.
Key numbers
- Lead 0.05 to 0.17 “mg/g”, cadmium 0.03 to 0.05 “mg/g”, chromium 0.28 to 0.65 “mg/g”, nickel 0.06 to 0.10 “mg/g” (Table 1, p. 1543).
- Taken at face value, the lead unit means 50 to 170 mg/kg, which is implausible for chocolate; the true unit cannot be determined from the paper.
Methods (brief)
Samples were oven-dried at 70 °C, ground, and about 1.5 g was digested on a hot plate in nitric acid and hydrogen peroxide, then read by flame atomic absorption. A reagent blank was run; no detection limits, reference materials or recoveries are reported.
Evidence Fitness
Very weak: four products, one supermarket, no quality control, and a unit label that cannot be reconciled with plausible chocolate levels. All findings carry an integrity flag and no converted value. Chocolate is a proxy for chocolate pudding and chocolate nut candy, which are not linked.