Overview
Omosigho, Balogun, Ataikiru, and Obetta measured pH, moisture/volatile content, and five metals in five toothpaste products purchased in Warri, Delta State, Nigeria. Cadmium, copper, zinc, manganese, and lead were detected in every coded toothpaste sample. The paper is directly routeable to the toothpaste product page as small-sample market occurrence evidence, with the coded sample design preserving product-category signal without brand-level publication in the wiki.
Key numbers
The authors report that samples M, N, and O were local toothpastes, while samples P and Q were foreign toothpastes. They do not publish product names in the concentration table.
| Sample | pH | Moisture and volatile content |
|---|---|---|
| M | 6.64 | 3.4% |
| N | 6.64 | 3.2% |
| O | 6.87 | 4.2% |
| P | 7.03 | 3.1% |
| Q | 6.59 | 7.4% |
Table 2 reports metal concentrations in mg/kg:
| Metal | Sample M | Sample N | Sample O | Sample P | Sample Q | Source-reported range |
|---|---|---|---|---|---|---|
| cadmium (Cd) | 2.470 | 2.952 | 2.727 | 2.791 | 2.663 | 2.470-2.952 |
| Cu | 0.866 | 1.123 | 5.165 | 0.096 | 0.802 | 0.096-5.165 |
| Zn | 24.164 | 14.912 | 14.552 | 14.013 | 12.396 | 12.396-24.164 |
| Mn | 2.278 | 2.438 | 2.117 | 3.402 | 1.700 | 1.700-3.402 |
| lead (Pb) | 5.642 | 6.113 | 5.715 | 5.582 | 4.917 | 4.917-6.113 |
Table 3 compares those values with source-reported reference values: cadmium (Cd) 2 mg/kg, Cu 0.603 mg/kg, Zn 14-30 mg/kg, Mn 2-5 mg/kg, and lead (Pb) 10 mg/kg. On that comparison, all five Cd values exceed the cited Cd value, most Cu values exceed the cited Cu value, and all Pb values are below the cited Pb value.
Methods (brief)
The study purchased five toothpaste products from Edjeba market in Warri, Delta State. For metal analysis, 1 g of dried toothpaste was digested with a perchloric acid, nitric acid, and sulfuric acid mixture in a 2:2:1 ratio, heated, treated with 4 M hydrochloric acid, filtered, and diluted to 100 cm3 with deionized water. The selected metals were determined by atomic absorption spectrometry.
The paper reports total metals only. It does not report chromium, arsenic, mercury, or metal speciation. It does not provide analytical LOD or LOQ values.
Implications
Certification: Direct occurrence evidence for total Pb and Cd in toothpaste products sold in Nigeria, but the sample size is small and product identities are coded.
Courses: Useful for showing how routine oral-care products can contain measurable total metals and why coded market sampling needs careful interpretation.
App: Supports a toothpaste category note that a small Nigerian market sample detected Cd, Pb, Cu, Zn, and Mn in every tested product.
Related evidence
Update history
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