Procedure for Analysis of Radium in Freshwaters by Adsorption on Basic Lead Rhodizonate

Ganzerli, M. T. Valentini; Maggi, Lauretta; Caramella, V. Crespi

doi:10.1021/ac980673o

Cited by 8 publications

(7 citation statements)

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“…3,4,6,7 The K d values for LERHO are different at low and high temperatures. 4 In the case of PRTD, the observed differences are minimal but the adsorption kinetics are slower. 6 In all cases, values at pH 9-9.5 near boiling temperature are high enough (>5 3 10 3 ) to allow a good adsorption yield.…”

Section: Adsorbersmentioning

confidence: 99%

“…The preparation and analysis of LERHO, partially basic lead rhodizonate supported on charcoal, has already been reported. 4 In all experiments the adsorber LERHO 32, containing 31.6% of lead rhodizonate, was employed.…”

Section: Adsorbersmentioning

confidence: 99%

“…The cation exchange properties of the adsorbers were tested after each preparation by evaluating the distribution coefficient, K d , for barium by a batch procedure at pH 9-9.5 since the chemical procedure is carried out by adsorbing radium at this pH. 3,4,6,7 The K d values for LERHO are different at low and high temperatures. 4 In the case of PRTD, the observed differences are minimal but the adsorption kinetics are slower.…”

Section: Adsorbersmentioning

confidence: 99%

“…Previous research has been directed toward the use of inorganic ion exchangers to isolate and concentrate radium from solutions of different compositions, including natural fresh water, in order to set up a simple and speedy analysis procedure. [2][3][4] Two exchangers, partially basic lead rhodizonate supported on charcoal, LERHO, and partially reduced tin dioxide, PRTD, were shown to be able to adsorb radium from basic solutions. PRTD was initially studied for isolating 90 Sr, but was shown to adsorb barium more strongly, and was also studied for its usefulness in assaying radium concentrations.…”

Section: Introductionmentioning

confidence: 99%

“…PRTD was initially studied for isolating 90 Sr, but was shown to adsorb barium more strongly, and was also studied for its usefulness in assaying radium concentrations. 5 The preparation and characterisation of LERHO [2][3][4] and PRTD [5][6][7][8] have been reported elsewhere. Both adsorbers were demonstrated to work better in batches because of their poor mechanical stability and their relatively slow adsorption kinetics.…”

Section: Introductionmentioning

confidence: 99%

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Determination of 226Ra in biological samples by adsorption on specific adsorbers

Maggi

Caramella

Ganzerli

2001

Analyst

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The determination of 226Ra in biological samples, such as milk and grass, was studied. 226Ra analysis of cow's milk was studied starting from de-fatted milk. The proteins were eliminated by coagulation of the colloidal phase with trichloroacetic acid. Phosphorus was then removed by precipitating it as molybdophosphate and finally adsorption was carried out by using two different adsorbers in order to concentrate and purify radium. Lead rhodizonate (LEHRO) adsorbed on charcoal and partially reduced tin dioxide (PRTD) were utilised. A method for the determination of 226Ra in grass ashes was also investigated. The main interference, due to magnesium, hinders the use of LERHO, so the proposed procedure is based on adsorption of radium on PRTD at pH 9.5. The magnesium concentration was depleted by precipitating barium (carrier) and radium with calcium carbonate at pH 8 before the adsorption step. The high phosphorus concentration in grass also interferes in the determination of 226Ra; phosphorus was eliminated as above via molybdophosphate precipitation. The radium was carried by barium and spiked with 133Ba. The yield of the chemical procedure was evaluated on the basis of 133Ba activity. Radium samples were alpha-counted and the activity was evaluated with a suitable calibration curve. Both exchangers in the milk analysis and PRTD in grass analysis were shown to be helpful in order to set up an easily performed procedure, which allows many samples to be processed simultaneously. All the methods adopted were shown to be very sensitive. Under the experimental conditions used, with 1 L of milk or 5 g of grass ashes, the limit was about 3 mBq 226Ra L-1 milk and < 1 mBq 226Ra g-1 grass ashes.

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Section: Adsorbersmentioning

confidence: 99%

Section: Adsorbersmentioning

confidence: 99%