Nuclide [5]. The permitted activity concentration of 226 Ra in drinking water according to Serbian legislation is 0.49 Bq/L [6]. The international guidance level for naturally occurring 226 Ra content in drinking water is set to 1 Bq/L, based on the Planet Health Organization [7]. 226 Ra may be detected straight via its -particle or -ray emission. Another way is indirect measurement in the activity of its progenies where radioactive equilibrium is required: -particles (emitted from 222 Rn, 218 Po, 214 Po), -particles (emitted from 214 Pb, 214 Bi) and -ray emitters (again 214 Pb, 214 Bi) enable indirect determination of 226 Ra [8]. The EPA (Environmental Protection Agency) has approved 17 procedures for 226 Ra evaluation in drinking water [9]. Seven from the approved strategies use a radiochemical/precipitation methodology to measure the total soluble alpha-emitting radioisotopes of radium, namely, 223 Ra, 224 Ra and 226 Ra; ten from the methods use a radon-emanation methodology which is certain to 226 Ra. The radiochemical techniques do not normally give an precise measurement of 226 Ra content material when other radium emitters are present, but might be made use of for the screening in the samples [9]. There have already been couple of current attempts in the literature to evaluate and evaluate many analytical methodologies for radium determination [102]. One study [10] evaluated gamma spectrometry, liquid scintillation counting (LSC) and alpha spectrometry for radium measurements in environmental samples, concluding that -spectrometry coupled with chemical separation offered maximal sensitivity having a detection limit of 0.1 mBq/L (roughly two orders of magnitude decrease than low-background HPGe -spectrometry and LSC strategies). For monitoring purposes in water samples, -particle spectrometry was determined because the most appropriate approach for 226 Ra measurements [12]. The newest study [11] determined that LSC spectrometry coupled with extractive methods and alphabeta discrimination provides one of the most precise, speedy and fairly simple determination of 226 Ra activity. This paper presents an exploration on the Cherenkov counting strategy on an LS counter, a strategy which has not been widely used for radium determination so far. The positive aspects of Cherenkov counting more than frequent LSC strategies are: reduce background count-rates and consequently reduced detection limits, non-usage of costly, environmentally unfriendly LS cocktails, and, consequently, simpler sample preparation with environmentally friendly disposal [13,14]. It has been documented that Cherenkov counting may be made use of for detection of GS-626510 Epigenetic Reader Domain difficult beta-emitting radionuclides via LSC, but its counting efficiency is sensitive to color quench, and is determined by the emitted -energy, the sample volume and its concentration, the kind of counting vial, rthe efractive index and also the variety of photocathode [15]. The motivation for the experiments presented in this paper was the lack of exhaustive information inside the literature regarding the optimization of LS counters and also the reliability of Cherenkov radiation detection for the goal of 226 Ra activity measurements. The uniqueness of this analysis lies within the truth that scientific literature didn’t Compound 48/80 Purity & Documentation introduce precise information on detection limits and methods for its reduction in the case of 226 Ra measurement through Cherenkov counting. Hence, this paper provides a novel, in depth analysis of Cherenkov counting by way of LS counter: a step-by-step optimization from the Quantulus 1220TM detector with an eva.