Determination of trace elements in djenkol bean using neutron activation analysis technique

Abstract

Djenkol (Archidendron pauciflorum) is a typical plant that grows in Southeast Asia, including Indonesia. Djenkol bean is widely consumed both as a vegetable and as a medicinal plant. In addition to the compound content, the trace element content in it is also interesting to be studied. Trace elements play an important role in the biological system, and some of them are needed by the human body in a certain amount of intake. In this study, djenkol bean was taken from 3 regions where the level of production was high and as a comparison of geographical origin, namely Pandeglang (Banten), Cianjur (West Java), and Magelang (Central Java). Each djenkol bean was cleaned from the rind and boiled at temperature above 80⁰C until cooked. The trace element content in the sample was determined using a neutron activation analysis (NAA) technique with comparative method. NAA is one of the most sensitive nuclear analysis techniques for determining multi-element content in materials. The analysis shows that djenkol bean contained with means in mg/kg: Mn (109) > Na (89) > Rb (24) > Fe (22) > Zn (10) > Br (7) > Ba (4) > Cr (0.5) > Co (0.03). Based on the distribution of elemental concentrations from the three regions, the coefficient of Pearson correlation is r>0.88, P<0.005, indicating the difference in geographical origin does not significantly affect the concentration of all elements in djenkol bean. Djenkol bean contains Mn as an essential trace element with fairly high concentration. Besides, the content of heavy metals (such as Cr and Co) can also be determined, and the value is still below the allowable limit value.