An easy method for Ra-226 determination in river waters by liquid-scintillation counting

Abstract

226Ra activity concentration in river water was determined using a low background liquid scintillation counter. Radium was extracted from the samples as Ra-BaSO4 precipitate which, afterwards, was dissolved with EDTA in ammonia medium. Solution was transferred into a low potassium glass vial and then mixed with a scintillation cocktail. Two different scintillation cocktails were selected for comparison. Efficiency, recovery yield and a/~ separation were studied with both liquid scintillation cocktails. One single measurement, made one month after radium separation, allows to calculate the 226Ra concentration as well as to assess the presence of alpha contamination of the sample. In the case of negligible interferences, 224Ra concentrations can be subsequently evaluated in the same sample by the measurement made just after chemical separation of radium. This method has been applied for the determination of 226Ra and 224Ra activity concentrations in river water collected from different locations along the Odiel river estuary area (South-west of Spain). The presence of chemical industry, the wastes of which are released into the river, could be connected with radium activity concentration enhancements in the water.

Self-cleaning in an estuarine area formerly affected by 226Ra anthropogenic enhancements

“…In addition, the transference of radium from water into sediment can also be driven by adsorption of suspended matter. The behaviour of Ra from phosphogypsum 226 samples has been studied by Moreno et al (1999) and Aguado (2003). Phosphogypsum is composed by a soluble phase and an insoluble phase in water.…”

Application of a liquid scintillation counter to the measurement of tracing radioactivity in experiments on suspended matter uptake in aquatic environments

“…A higher level of 2.4 cpm was measured in water collected from the Tinto estuary. This result can be attributed to the presence of natural alpha emitters in the sample [7]. Table 3.…”

Application of in-house method for determinationof radium isotopes in environmental samples usingthe Liquid Scintillation counting technique

“…Radium is commonly measured using a various analytical procedures and equipments. The most common methods for determining radium isotopes are alpha spectrometry [1,2], gamma spectrometry [3][4][5], Cerenkov counting [6] and liquid scintillation counting [7][8][9][10][11][12][13][14]. Alpha spectrometry is the most sensitive technique and allows simultaneous measurement of α-emitting radium isotopes but it is difficult to isolate the radium from other alkaline earth metals [15][16][17].…”

“…The radionuclides of 226 Ra and 228 Ra can be measured in environmental samples using a range of techniques with offers a number of advantages such as time saving and simplicity [21]. Through LSC methods also, radium in mineral waters [22], contaminated rivers [8] and phosphogypsum samples [23] can be measured. The aim of the study is to develop a simple method for determination of 226 Ra and 228 Ra in environmental samples using the α-β coincidence LSC.…”