Determination of certified values for Co, Cr, and Zn in lake sediment CRM (KRISS 109-05-002) using the INAA method

The standard calibrator–instrumental neutron activation analysis method was used to characterize the mass fractions of Co, Cr, and Zn in a lake sediment certified reference material (CRM) developed by the Korea Research Institute of Standards and Science. The method was validated for each element and sediment matrix, and the CRM analysis was repeated to ensure reproducibility and address potential matrix interferences. To verify measurement reliability, quality control samples were also assessed. For lake sediment samples with a small Zn peak and dominant adjacent peaks of Eu and Sc, sequential measurements were performed to obtain accurate Zn concentrations. The optimal measurement timing was when the Sc peak sufficiently decayed and the intensity of the Zn peak remained larger than that of Eu. Moreover, an appropriate fitting program capable of deconvoluting complex peak regions is necessary.