Adegbola et al. 2015 — Metals in snacks and drinks sold in Ibadan, Nigeria

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 Cr only, with no 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 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, 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.

Wiki pages this source may touch

• 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 (HMTc Category 24 master)
• Lead
• Cadmium
• Chromium
• Copper
• Iron

Verification notes

• PDF text extracted with pdftotext -layout; the extracted text contained the title page, DOI, abstract, methods, Tables 1-4, discussion, conclusion, and references.
• DOI verified from the first page as 10.4314/ijbcs.v9i3.47; DOI, raw-handle, and cite-key checks found no existing source page before creation.
• Table ranges were checked against Tables 1-4. Units are preserved as printed (mg/l in Table 1 and mg/L in Tables 2-4); no unit conversions were performed.
• Speciation: chromium is total Cr only. The source does not report Cr-VI, arsenic, mercury, or methylmercury.
• Brand firewall: the text states that popular brands were sampled, but the tables use coded sample IDs. This page reports product-group ranges only and does not attach public brand names to values.
• Calcium was measured and is included in frontmatter as Ca, but the taxonomy snapshot does not list a metals/calcium page, so no calcium wiki-link is added.
• Frontmatter product and ingredient slugs were checked against docs/gpt-collaboration/taxonomy-snapshot.md; no new product or ingredient slug was invented.
• Source-internal sample-count discrepancy: the abstract and methods narrative state 12+6+11+5=34 brands, but the four tables show 12+6+12+5=35 rows (Table 3 lists C1-C12 = 12 milk-candy and fruit-concentrate samples, while the methods describe 11 fruit-and-flavoured concentrate brands). This page follows the source’s stated total (34) and reports the per-table n from the table rows; the source itself is internally inconsistent on the total.
• Source-internal discussion-text inconsistency (noted, not propagated): the discussion text states “Highest lead concentration was found in sample A2 (0.39±0.052 mg/kg)” but Table 1 shows A1=0.90±0.069 is the highest Pb in sweets. This page uses the table values, not the discussion-text claim. The CAC (2003) compliance statements quoted from the discussion remain accurate to the source’s wording (the CAC permissible-limit claims do not depend on which sample was the maximum).
• 2026-06-09 audit (autonomous): REVISE verdict. Numerical fidelity ✅ across all four tables; methods ✅; speciation ✅; brand firewall ✅; HMTc firewall ✅. The audit’s only ❌/⚠️ concerns were the source-internal sample-count discrepancy (added to verification notes here) and a flag on matrices: vocabulary. The matrices flag was a false positive: per existing wiki convention matrices: is a free-form descriptive vocabulary listing the physical sample types in the source, not a closed slug list like products: or ingredients:, and product/matrix overlap (e.g., carbonated-drinks matrix vs soft-drinks-carbonated-beverages product) is expected — the two vocabularies serve different purposes (what was sampled vs HMTc routing).

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.