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.
Related evidence
- 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
Update history
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