Evaluation of some heavy metal contaminants in biscuits, fruit drinks, concentrates, candy, milk products and carbonated drinks sold in Ibadan, Nigeria

Overview

Adegbola and colleagues measured calcium, chromium, copper, iron, lead, and cadmium in 34 snack, drink, candy, biscuit, concentrate, and milk-product samples sold in Ibadan, Nigeria. The samples were cold-digested with hydrochloric acid and nitric acid and analyzed by flame atomic absorption spectrophotometry. The paper reports coded sample IDs rather than public brand names in its tables; this page keeps the occurrence data at the product-group level. Chromium is reported as total chromium (Cr) only, with no hexavalent chromium (Cr-VI) speciation.

Key numbers

Sample-group ranges from Tables 1-4:

Additional source-reported values:

• Sample counts: 12 sweet and milk-sweet brands, 6 biscuit brands, 11 fruit and flavoured concentrate brands, and 5 liquid drink types.
• The abstract states that calcium and iron were present in all samples, while chromium, copper, lead, and cadmium were not detected in some samples.
• The abstract states that calcium had higher concentration than other heavy metals in all samples.
• The discussion states that cadmium concentrations did not exceed 1.5 mg/kg and lead concentrations did not exceed 2.5 mg/kg, citing CAC (2003).
• Table 4 reports one juice/milk-shake lead value as 1.21±1.04 mg/L; this is the highest lead (Pb) value printed in the source.

Methods (brief)

The authors collected popular brands of sweets, biscuits, fruit and flavoured concentrates, and liquid drinks sold in Ibadan, Nigeria. Solid samples were ground with a porcelain mortar and pestle; 5 g of each solid sample or 5 mL of each liquid sample was treated with 10 mL concentrated hydrochloric acid and 10 mL nitric acid for 18 hours in a fume cupboard. Digests were filtered, made up to 100 mL with distilled water, and analyzed for calcium, chromium, copper, iron, lead, and cadmium using a Perkin Elmer A Analyst 200 flame atomic absorption spectrophotometer with an air-acetylene flame. The paper reports total chromium only and does not describe arsenic, mercury, or chromium speciation.

Implications

This source contributes Nigeria-market occurrence evidence for Pb, cadmium (Cd), total Cr, Cu, Fe, and Ca across multiple snack and beverage categories frequently consumed by children. Its strongest routing value is broad product-surface coverage: biscuits/snack products, fruit-flavoured beverages and concentrates, carbonated drinks, and milk-product beverages. The mixed matrix set should stay grouped by product family during later extraction, and total Cr cannot be used as Cr-VI evidence.

Related evidence

• Beverages
• Fruit Juice
• Milk and Dairy
• Snacks Crackers Biscuits — REDIRECT (Cat 7 sub-variant of Snacks, general)
• Category 5: Beverages
• Fruit Juices, Non-Apple
• Soft Drinks/Carbonated Beverages
• Milk and Dairy
• Lead
• Cadmium
• Chromium
• Copper
• Iron

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git.