Cupric fungicides are widely applied in grain production to prevent low productivity and organoleptic

changes. However, the ingestion of these compounds poses significant health risks to humans and

animals when exposed to the oral route of absorption. In this work, we evaluate the applicability of

nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) for

copper quantification in different grains using isotope dilution (ID) analysis. Commercial and certified

organic samples of beans and peanuts are studied to evaluate the potential contribution of the fungicide

Although inductively coupled plasma mass spectrometry (ICP-MS) is widely applied for trace element

analysis, the use of argon as a plasma gas can lead to polyatomic isobaric interferences— such as

40Ar23Na overlapping with 63Cu— that affect accuracy and traceability. MICAP-MS offers an alternative

by using nitrogen as the plasma gas, which reduces operational costs and eliminates argon-related

interferences. The determination of copper is performed by using external calibration and ID analysis

for comparison, and interference from residual carbon is also evaluated. After instrumental

optimization, the developed method is applied to grain samples to understand copper levels in organic

and non-organic food samples.