Alemu, Adanech (2008) Levels of Essential and Toxic Metals in Commercial Powdered Infant Formulas. Masters thesis, Addis Ababa University.
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PDF (Levels of Essential and Toxic Metals in Commercial Powdered Infant Formulas)
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Abstract
Samples of infant formulas were collected from different supermarkets. After preparation of samples, different digestion procedures were tested by varying reagent volumes, digestion time, temperature and amount of the sample to develop a procedure that consumes less regent volumes, short digestion time, low temperature of digestion and smaller mass of the sample. The optimal procedure required 4:00 hours and consumed 3mL HNO3 and 2 mL HClO4 to completely digest 0.5 g of powdered infant formula samples. The accuracy of the optimized procedure was evaluated by analyzing the digest of the spiked samples with standard solution. Recoveries of the spiked samples varied from 91.33 % to 115.0 % for infant formula samples. Concentrations of essential and toxic metals in the samples were analyzed by flame atomic absorption spectrometer (FAAS) employing a four point external calibration curve. The observed average metals concentrations were (mean ± SD, µg/g and N = 9): Ca (2138.21 ± 13.35), Mg (274.70 ± 4.55), Fe (62.72 ± 1.22), Zn (32.53 ± 2.35), Cu (2.73 ± 0.10), Mn (0.65 ± 0.02) in NAN; Ca (2331.08 ± 20.67), Mg (310.58 ± 2.87), Fe (75.70 ± 2.55), Zn (42.98 ± 1.35), Cu (3.68 ± 0.30), Mn (0.84 ± 0.05) in S-26; Ca (2294.15 ± 19.85), Mg (295.24 ± 3.27), Fe (76.49 ± 1.77), Zn (42.21 ± 0.57), Cu (3.07 ± 0.27), Mn (1.01 ± 0.023) in Bebelac; Ca (2445.47 ± 24.49), Mg (298.35 ± 3.35), Fe (65.28 ± 4.09), Zn (39.41 ± 0.78), Cu (2.86 ± 0.15), Mn (0.56 ± 0.01) in Guigoz. This study showed that the metal contents of infant formulas vary with brands. The toxic metals (Pb and Cd) were not quantified in all brands of infant formulas, which were below the method detection limit. The daily intakes of the essential metals were calculated by using the feeding tables specified by the manufacturers of the various brands. The results were compared with recommended dietary allowances (RDA) and dietary reference intakes (DRI) for use in North America. The average daily intakes of most metals in powdered infant formulas were comparable with the recommended values, but showed lower or higher than the recommended values for some metals. The levels of metals in infant formulas are comparable with that of the manufacturers and literature values.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Infant formulas, Flame atomic absorption spectrometer (FAAS), Essential metals, Toxic metals |
| Subjects: | Q Science > QD Chemistry R Medicine > RJ Pediatrics R Medicine > RJ Pediatrics > RJ101 Child Health. Child health services |
| Divisions: | Africana |
| Depositing User: | Selom Ghislain |
| Date Deposited: | 18 Jun 2018 12:07 |
| Last Modified: | 18 Jun 2018 12:07 |
| URI: | http://thesisbank.jhia.ac.ke/id/eprint/4426 |
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