Studies on bioaccessibility of elements were carried out by in-vitro gastrointestinal digestion simulation method combined with neutron activation analysis (NAA) using NH₄HCO₃ as an alternate base to commonly used base of NaHCO₃. The effect of two bases namely NaHCO₃ and NH₄HCO₃ on the bioaccessibility of the elements namely Br, Fe, K, La, Na, Rb, Sm and Zn from wheat seeds, fresh wheatgrass and commercial wheatgrass tablet was investigated. The bioaccessible concentrations of the elements were determined by neutron activation analysis (NAA). The bioaccessible concentrations of samples digested using NH₄HCO₃ were found to be higher by 10–15% for most of the elements than that observed using NaHCO₃. In the case of fresh wheatgrass, the differences were as high as 50%. The present study indicated that NH₄HCO₃ can be used as a base instead of NaHCO₃ in in-vitro gastrointestinal digestion simulation method.