Overview
This method-development paper also reports direct Pb occurrence results for 20 commercial infant formula samples. Four of 20 samples were positive for Pb, with SPE-CE and ETAAS results compared on the same positive samples.
Key numbers
Lead occurrence in positive infant formula samples (Table 5; ug/kg):
| Anonymized positive sample | SPE-CE Pb | ETAAS Pb |
|---|---|---|
| 1 | 10.26 (RSD 1.47%) | 11.19 (RSD 1.74%) |
| 2 | 13.21 (RSD 0.90%) | 13.77 (RSD 1.14%) |
| 3 | 27.73 (RSD 1.50%) | 28.43 (RSD 2.21%) |
| 4 | 42.59 (RSD 1.51%) | 44.00 (RSD 1.94%) |
Source-reported summary and method performance:
- Four of 20 commercial infant formula samples were positive for Pb.
- The abstract reports positive-sample Pb concentrations ranging from 10 to 43 ug/kg.
- The proposed SPE-CE method had an LOD of 0.5 ug/L and LOQ of 1.5 ug/L.
- Intra- and inter-day repeatability were less than 5% RSD.
- Recovery was 104% (RSD 3.5%) at 5 ug/L and 99% (RSD 2.7%) at 15 ug/L.
- ANOVA found no significant difference between SPE-CE and ETAAS results (alpha=0.05).
Methods (brief)
The paper synthesized a Pb(II)-imprinted polymer using methacrylic acid and 4-vinylpyridine functional monomers with ethylene glycol dimethacrylate as cross-linker. Infant formula was reconstituted as instructed by the manufacturer (4.5 g in 30 mL water), protein was precipitated with 2% acetic acid, and the supernatant was passed through an imprinted-polymer SPE cartridge before capillary electrophoresis. Positive samples were cross-checked by electrothermal AAS after nitric acid/hydrogen peroxide microwave digestion using a CEM MARS 6 system. The capillary-electrophoresis system was a Beckman Coulter P/ACE 5500-DAD; ETAAS used an Agilent/Varian 240FS AA spectrophotometer with GTA 120 graphite tube atomizer.
Implications
Standards work: This source contributes direct Pb occurrence evidence for commercial infant formula, but the product matrix is tied to a method-validation study and only the four positive samples are numerically tabulated.
Courses: Useful for showing why method-validation papers can still contain usable occurrence values when real commercial samples are analyzed and positive results are reported.
App: Provides Pb occurrence fields for positive infant formula samples. The source does not support product-brand comparison.
Microbiome: Not addressed.
Wiki pages this source may touch
- Lead
- Infant Formula Powder
- Infant Formula Powder
- Infant Formula, Powder (Non-Soy)
- Commission Regulation (EC) No 1881/2006 setting maximum levels for certain contaminants in foodstuffs
Verification notes
- Fresh auto-fetch ingest 2026-05-19 from the gap-driven infant-formula wishlist. The wishlist target metal was Ca because the paper discussed Ca as an interferent, but the usable occurrence endpoint is Pb.
- Strict brand firewall: the paper reports only anonymized positive sample numbers in the result table. This page does not name or rank commercial brands.
- The “10 to 43 ug/kg” range in the abstract is reconciled with Table 5 values of 10.26-42.59 ug/kg by preserving the exact Table 5 values and noting the abstract’s rounded range.
- Methods vendor/equipment names are retained under Part 12 Exception 2.
Update history
This page has no substantive edit history yet. Future revisions will be recorded here once the change lands in git.