Reply to query related to “Study of uranium contamination of ground water in Punjab state in India using X-ray fluorescence technique”

Abstract

The queries made by Rathore in the preceding Letter to Editor (J Radioanal Nucl Chem, 2013) regarding the “Studies of ground water contamination in Punjab state in India using X-ray fluorescence technique” by Alrakabi et al. (J Radioanal Nucl Chem 294:221–227, 2012. doi: 10.1007/s10967-011-1585-x), are responded. The points raised by Rathore are important in case of sensitive analytical techniques, where only a small fraction (~few hundred μL of water) of the water sample collected in the container is effectively used as analyte. The biasing due to chemical speciation and physical escape of element of interest becomes significant in such rapid techniques if the ionic species of interest in the analyte are not stabilised using suitable additives. In the reported study based on X-ray fluorescence technique, the analyte used for elemental analysis was obtained by drying about 500–1000 mL of water sample. Adequate precautions were taken to minimize possibility of element of interest to escape or adhere to the bottle surface or lost as residue. The onsite acidification of collected water sample to pH 1 with reagent-grade nitric acid for sample preservation is not a pre-requisite in the procedure followed. The contribution of particulate matter to the reported concentrations of uranium was estimated to be insignificant. Also, the query related to effect of co-precipitation of uranium with formation of CaF₂ is found to be inconsequential. The comment made by Rathore (J Radioanal Nucl Chem, 2013) stating that ‘proceeding further in the measurement of uranium is a waste of time and has no meaning and results and discussion have no meaning too’ is extraneous.