Factors affecting total dissolved solids concentration of γ-ray-irradiated aqueous hexamethylenetetramine solution: A dosimetric study

• Total dissolved solid (TDS) meter was used to follow up some effects of γ-ray radiation on aqueous hexamethylenetetramine (HMTA) solutions.
• Factors affecting the TDS concentration of γ-radiated of HMTA solutions were studied.
• TDS meter–HMTA aqueous solution could be considered as a promising candidate for γ-ray radiation dosimetry specially in medical and biological fields.

A new γ-ray-radiation dosimetric system (TDS-HMTA), comprising a 'total dissolved solids (TDS)' meter and 0.02 M aqueous hexamethylenetetramine (HMTA) solution, is introduced for medical and biological applications. Gamma-ray radiolysis of aqueous HTMA solutions increases the concentrations (ppm) of TDS, which is measured by the TDS meter. The effects of HMTA concentration, absorbed radiation dose, absorbed dose rate, and storage time on the TDS concentration of irradiated HMTA solutions were studied. It was found that 0.02 M aqueous HMTA solution yields the highest sensitivity to γ-ray-radiation according to TDS concentration measurements. The effect of absorbed radiation dose was studied in the range 1.64–435.5 kGy. The TDS concentration increases linearly up to the maximum of the studied absorbed radiation dose range (R2 = 0.9965). The overall coefficient of variation (CV %) associated with TDS concentration measurements of 0.02 M HMTA solution as a function of absorbed dose was found to be 0.732%. The effect of dose rate on the TDS concentration was studied in the range 0.33–3.31 kGy/h. It was found, also, that the TDS concentration is relatively stable over a storage period of 144 h after irradiation with different doses. The tissue equivalency of 0.02 M aqueous HMTA solutions allow it to be used for radiation dose measurement during sterilization in human tissue banks. Therefore, this system (TDS–HMTA) could be considered as a promising candidate for γ-ray radiation dosimetry in technical, medical and research fields.