Overview
Bakare-Odunola and Mustapha bought 20 zobo (a sweetened roselle calyx drink) and 20 kunnu zaki (a cereal drink) samples in Samaru-Zaria and measured iron, lead, zinc and copper by flame AAS. Chromium, manganese, silver, mercury and bismuth were tested only qualitatively and were absent in all samples. Results are per litre of drink.
Key numbers
- Zobo lead: 0.54 to 1.28 mg/L in detected samples, mean 0.84 ± 0.29 mg/L (Tables 3 and 5).
- Kunnu zaki lead: mean 2.54 ± 6.29 mg/L (Table 5), inflated by one sample printed as 27 mg/L (Kz2, Table 4) that conflicts with the stated range of 0.80 to 1.55 mg/L.
- Kunnu zaki iron mean 23.34 ± 3.3 mg/L; zobo iron 3.54 ± 2.19 mg/L (Table 5).
Methods (brief)
100 mL of each drink was evaporated, digested with nitric, perchloric and hydrofluoric acids, extracted with APDC into MIBK and read by flame AAS. No detection limit, reference material or recovery is reported. Mercury was not quantified instrumentally.
Evidence Fitness
Forty market samples from one town, with no sampling dates, detection limits or quality control. The Kz2 lead value is probably a typing error and is flagged. Lead near 1 mg/L in both drinks is high and comes from a flame method with no validation data. Zobo is a roselle calyx drink and is a proxy for cranberry-juice-cocktail, fruit-ice-pop and fruit-juice-ready-drinks; those pages are not linked. Cadmium and arsenic were not measured.