Determination of trace elements in Brazilian human milk by quadrupole inductively coupled plasma mass spectrometry and microwave-assisted digestion

A fast procedure to determine Al-27, Cr-53, Mn-55, Fe-57, Ni-60, Cu-65, Zn-64, Zn-66, Se-78, Se-82, Cd-112, Cd-114, Pb-206, Pb-208, Ba-138, V-51, Co-59, and As-75 in Brazilian human milk by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) is proposed. Mature and colostrum human milk samples were mineralized using closed-pressurized and high-performance microwave (MW) oven digestion. Aqueous calibration was performed with an r(2) higher than 0.99 for all isotopes investigated. A reference material, Infant Formula (NIST SRM 1846), was analyzed to test the accuracy of the proposed methodology. In addition, recovery assays were carried out to check the interference effects. Recoveries ranged between 80.8% and 110.9%. The precision of the method, expressed as a relative standard deviation (RSD), was better than 3.4% for all analytes investigated. Precision and accuracy of the method show that it is useful for the intended purpose.