Fast and simultaneous determination of zinc and iron using HR-CS GF-AAS in vegetables and plant material

Due to the high nutritional importance of zinc and iron, accurate methods for their determination in foodstuffs are required. Here, we present a routine-ready method for their co-determination by means of high-resolution continuum source graphite-furnace atomic absorption spectrometry. As the technique allows for monitoring a narrow spectral interval, adjacent secondary lines of Zn (307.588 nm) and Fe (307.572 nm) can be measured simultaneously in a single firing. The analysis is therefore fast (under 2 min) and its sensitivity corresponds to common concentrations of the elements in foodstuffs. The accuracy of the method was verified by means of reference materials and also by comparison with an independent technique. Analysis of a large set of vegetable samples proved the applicability of the method in a routine laboratory setting. The vegetables for analysis were obtained from both markets and local gardeners. The results indicate higher contents of zinc and iron in homegrown vegetables compared to store-bought ones.