A method for quantification of arsenic, cadmium, mercury, and lead in pineapple using inductively coupled plasma-mass spectrometry (ICP-MS) was developed, validated, and used to test the homogeneity and stability of in-house reference materials.The method was tested at the regulation levels given by the Food and Agriculture Organization of the United Nations (FAO, 100 µg kg -1 ).The mineralization conditions of the samples, in a microwave oven, were improved throughout the study of HNO 3 and H 2 O 2 concentrations, sample weight, time, and temperatures.The calibration was made by a gravimetric standard addition method with internal standard correction.The validation parameters were accuracy (trueness as recovery, between 97-112%, and precision as repeatability, below 12%), limits of detection (As 14.2, Cd 1.5, Hg 21.9, and Pb 5.4 µg kg -1 measured in pineapple), linearity and selectivity.The in-house material was lyophilized or dried in an oven.The best way to dry it was by the oven process because it has the lowest uncertainty.