Preparation of In-House Calibration Standard Solutions for Mn, Co and Their Assay Using Nuclear Analytical Techniques

Calibration is the primary step in most of the instrumental analytical techniques. Separate calibration standard solutions of Mn, Co were prepared by dissolution of MnSO 4 ·H 2 O and Co metal in HNO 3 media. Neutron activation analysis and energy-dispersive X-ray fluorescence spectrometry were used for assay, homogeneity and stability assessments of these solutions. During the whole preparation, assessment processes, all care was taken to maintain an unbroken chain of comparisons, to establish the traceability of the present solutions to NIST reference standard solutions. The role of appropriate concentration range for multi-point calibration procedures was explicit by closely monitoring the intercept and slope of the least square curve. Accuracies of the measurements for different concentration ranges were compared in terms of the % error in the final calculated concentrations for quality control standards. Atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry were used to assess the impurity profiles in the in-house calibration standard solutions. The values of Co and Mn were assigned according to ISO Guide 80:2014 guidelines.