Application of neutron activation analysis in environmental studies

In this paper the ability of NAA in environmental researches is investigated. 71 samples of sediment from all over the Zayandehrood (River) in Isfahan province (Along 300 km) is collected and analysed and by INAA method. Because of variety of particles size in samples they sieved by two different mesh sieves (0.125 mm<Particle size<0.250 mm). From each collected portion, three samples were chose (each ∼ 120 mg) for different stages of analysis. Through three different stages of analysis 43 elements were analysed using 12 standard references materials. According to statistical counting errors, all elements can be classified in three groups. a)The elements with error less than 10% include Al,Ba,Ca,Ce,Co,Cr,Dy,Eu,Fe,Hf,K,La,Lu,Mg,Na,Rb,Sc,Sm,Ta,Th,Y,V,Zn (24 elements). b) The elements with error between 10% to 50% include As,Au,Cl,Cs,Nd,Ni,Sb,Sr,Tb,Ti,Tm,Yb,Zr (13 elements). c) The elements with error more than 50% include Ag,Cu,Ga,Hg,In,W (6 elements). Referring to above classification it can be concluded that in analysis of river sediment, NAA is an ideal method for analysis of 24 elements of first group. Concerning 13 elements of second group, because of ease, and low cost, this method is acceptable. But it is not acceptable for analysis of third group compared to the other methods of analysis