Rapid evaluation of gross alpha and gross beta in water samples for emergency response

This paper presents a three-stage protocol for gross alpha and gross beta evaluation in water samples in emergencies. The novelty of this approach is the great level of detail for its application in this type of sample, following the criteria proposed in well-established safety guidelines. This protocol makes use of a rapid method adapted from different proposals found in the scientific literature. The method is based on a simple preparation of the sample and a rapid measurement by liquid scintillation counting on Quantulus 1220, which permits the evaluation of waters with different salt content (from 5 g l(-1) of continental and drinking water, to 35 g l(-1) of seawater) and pH (from 1 to 8) in emergency situations. The protocol and the method allow to prioritize the most active samples and to assess contamination in less than 2 h. Both were tested and validated with spiked water samples with different ratios of alpha and beta emitters (1:1, 1:10 and 10:1) and with intercomparison water samples. Relative bias are below 10%, except in the samples with activities close to the limits of detection and relative standard deviation are below 10% in most of the samples, which give a clear idea of the robustness of the method.