A simple and fast ultrasound-assisted procedure for the determination of iron and zinc in infant formulas
is presented. The analytical determinations were carried out by flame atomic absorption spectrometry.
Multivariate experiments were performed for optimization; in addition, a comparative study was carried
out using two ultrasonic devices. A method using an ultrasonic bath was selected because several samples
can be prepared simultaneously, and there is less contamination risk. Analytical precision (sr(%)) was
3.3% and 4.1% for iron and zinc, respectively. Trueness was assessed using a reference material and by
comparison of the results obtained analyzing commercial samples using a reference method. The results
were statistically equivalent to the certified values and in good agreement with those obtained using the
reference method. The proposed method can be easily implemented in laboratories for routine analysis
with the advantage of being rapid and in agreement with green chemistry.