Fast and Sensitive Radiochemical Method for Sr-90 Determination in Food and Feed by Chromatographic Extraction and Liquid Scintillation Counting

Abstract

Strontium-90 (Sr-90) contamination in food is a major public health issue. Several radiochemical methods are available for the determination of Sr-90. However, the application of these procedures is not focused on solid foods, but only on liquid (milk, water, etc.) and environmental matrices, and they were not fully validated. The aims of this work were to establish and validate a fast, sensitive method for the determination of Sr-90 in solid food matrices such as meat and dairy products, seafood, vegetables, and animal feed, using a specific resin for extraction and ultra-low-level liquid scintillation counting for detection. The method was optimised and validated according to relevant legislation. Good analytical performance was obtained, including high specificity and linearity together with low measurement uncertainty (13.1%). The minimal detectable activity was 11 mBq kg−1, and the mean repeatability (CV%) and recovery values were 10.7% and 100.1%, respectively. These parameters assured method applicability for official food safety controls. The method was applied to reference materials and submitted to proficiency test round to confirm its reliability for Sr-90 quantification in solid foodstuffs and feed. The newly established method may be broadly applicable to complex matrices.

Scalable Dialysis-Based Method for the Isolation of Strontium from Milk for Radioanalysis

“…To contend with such complexity, many methods have been described for both routine and emergency contexts. ,− Among these, solid-phase extraction figures prominently, particularly with the development of commercially available supports bearing chelating agents of high specificity . Being convenient, and hence potentially well-suited to emergency response, such substrates typically require a small sample size (≤100 mL) with a preconcentration step via extraction or precipitation, − while others adhere to sample ashing. …”

“…32 Being convenient, and hence potentially well-suited to emergency response, such substrates typically require a small sample size (≤100 mL) with a preconcentration step via extraction or precipitation, 33−35 while others adhere to sample ashing. 36 To circumvent the need for sample ashing and potentially unreliable preconcentration steps, we wished to explore the possibility of using strontium fixation on cation-exchange resin as a thermodynamic driving force to fully deplete milk of its incorporated strontium across a semipermeable membrane barrier, as illustrated in Figure 1.…”

Detection and measurement of radioactive substances in water and food: a narrative review

“…The findings indicated that the minimum detectable activity was 8.0 mBq per kg, with a mean repeatability of 14.5% and a recovery rate of 90.5%. Marchesani et al ( 2022 ) developed and validated a rapid and highly sensitive technique to detect strontium-90 in solid food items like meat, dairy products, seafood, vegetables, and animal feed. This method involves the use of a specialized resin for extraction and ultra-low-level liquid scintillation counting for detection.…”

Practical aspects of the application of cherenkov counting method with the correction of sample’s color quenching

“…Відомо, що спектр оптичних сигналів, що реєструються фотоелектронним підсилювачем у разі ЧЛ, має низьку інтенсивність, що зумовлює його схильність до кольорового гасіння проб. Для стандартизації стану проб для ЧЛ застосовують багаторазове їх очищення від можливих барв-ників [2][3][4][5]. Ускладнення підготовки проб застосуванням цих процедур не гарантує ідентичності хімічного виходу підготовки і відтворення умов реєстрації b-випромінювання.…”