Overview
Coulibaly and colleagues digested seven clays eaten in Côte d’Ivoire in simulated gastric (pH 2.5) and small intestine (pH 7) fluids and measured the released elements by ICP-MS. The green Anyama clay released more elements than the kaolinitic Bingerville clays. Lead, cobalt, nickel and uranium releases were near zero, while aluminum, copper and zinc were released in larger amounts.
Key numbers
- Lead in gastric extracts: 0.01 mg/L for the Anyama clay (AVA) and one Bingerville clay (LVF); ”-” for all other extracts (Table 5).
- Aluminum: 5.20 mg/L (AVA, gastric) rising to 20.40 mg/L in the intestinal phase (Table 5).
- Copper: up to 1.69 mg/L (LRF, gastric) (Table 5).
Methods (brief)
One gram of clay was shaken in 100 mL of a pepsin-based gastric fluid at 37 °C for 1 h, then adjusted to pH 7 with bile salts and pancreatin for 2 h, following a modified Cave et al. (2003) protocol. Filtered extracts were analyzed by ICP-MS. No detection limits or QA are reported.
Evidence Fitness
Bioaccessibility data only: values are mg/L in extracts, not concentrations in the clay, and total metal contents are not reported, so the study cannot be compared with occurrence bands. Some table columns are misaligned and ”-” cells are undefined. The DOI is not printed in the PDF. Useful as context on how little lead is released from these clays; it is not evidence for cosmetic-clay.