Multielemental Method for Maternal Breast Milk Analysis by Inductively Coupled Plasma – Atomic Emission Spectrometry (ICP-AES) and Acid Digestion

Abstract

Maternal breast milk is the basic food for newborns since it contains various nutrients that are essential for their development. Different factors can affect the concentration of metal ions in human breast milk, which raises concerns about their levels in cases of exclusive breastfeeding. Therefore, the development of sensitive methods for the elemental assessment of maternal breast milk is of high importance. In this study, a simple and rapid method was developed for the determination of 14 metals and trace elements by inductively coupled plasma – atomic emission spectrometry (ICP − AES) in samples collected from volunteer lactating mothers at different stages of breastfeeding. Samples were subjected to acid digestion in a high pressurize closed-vessel system combined with heating. The reported method showed good repeatability (relative standard deviation < 4.0%), linearity (r > 0.9996), and accuracy (recovery values > 83.0%). Following its validation, the developed protocol was used for the screening of metals in 21 breast milk samples. The concentration values for Cu, Zn, Fe, Ca, Mg, and Al were 0.824 ± 0.08 mg kg⁻¹, 1.02 ± 1.02 mg kg⁻¹, 0.648 ± 0.2 mg kg⁻¹, 176.8 ± 45.9 mg kg⁻¹, 20.8 ± 5.5 mg kg⁻¹ and 0.103 ± 0.08 mg kg⁻¹, respectively. Ba, Cd, Mn, B, Co, Ag, Bi, and Cr were not detected in the samples.

Keywords:

• Acid digestion
• heavy metals
• human milk
• inductively coupled plasma – atomic emission spectrometry (ICP-AES)
• trace elements

Declaration of interest

The authors declare that they have no competing interests.