Quantitative evaluation of trace elements in sediments of the tamsui river via instrumental neutron activation analysis

The present study examined concentrations of trace elements in the sediments collected from 31 locations along the banks of Tamsui River by instrumental neutron activation analysis. The Tamsui River is famous for containing a unique area of naturally preserved mangrove in northern Taiwan. It is also the second longest river among the 3major rivers in Taiwan. Atotal of 11 nuclides, includingMg, Al, Ti,Mn, Na, Sc, As, Br, La, Fe and Cs, were identified. The categories and measurements of nuclides detected were interpreted according to the sampling locations or chemical attributes characteristics. Adimensionless index (CI) was introduced to explore the quantitative correlation among the detected nuclides. Asmaller CI corresponded to a stronger correlation between a pair of nuclides, such that the correlation between the nuclides can be interpreted through a series of quantified indices. The minimum detectable concentration (MDC) for As-76 was fluctuated around 0.67 ±0.09 μg/g due to the variations of background counts in various gamma spectra.