Levels of Essential and Toxic Metals in Commercial Powdered Infant Formulas
No Thumbnail Available
Date
2008-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
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 3
mL 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.
xi
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.
Key words: Infant formulas, Flame atomic absorption spectrometer (FAAS), Essential
metals, Toxic metals
Description
Keywords
Infant formulas; Flame atomic absorption spectrometer (FAAS); Essential Metals; Toxic metals