Radio-Caesium in Dried Milk

Ashing Procedures for Determination of Cesium in Plant and Animal Tissues.

“…(1) ASTM Standards on Petroleum Products and Lubricants, p. 694 (1958). (2) Benesi, H. A., Bonnar, R. U., Lee, C. F., Anal. Chem.…”

Health physics

“…The number of channels required depends on the particular application and on the energy resolution required. Thus for the routine measurement of potassium and 13'Cs in dried milk, a five-channel analyser was used by Booker (1957), but satisfactory operation required the absence of all other nuclides emitting gamma rays of energy greater than 0.7 MeV. A variety of analysers is currently available, having from 20 to 512 channels, and one of these is required where versatility of the measurement technique is demanded, i.e.…”

“…1 pile stack, provided an opportunity for the application of gamma-ray spectrometry as a routine tool for rapid monitoring of large numbers of samples. Booker (1958) has described the measurements made at Harwell on samples of milk, herbage and soil, mainly with the five-channel analyser and 3-inch diameter by 3-inch crystal used for routine measurements of potassium and 13'Cs in dried milk (Booker 1957). As 1311 was the major contaminant in all the early samples studied, it was possible to estimate the activity of this nuclide with the four channels of the analyser straddling the photo-peak at 0.364 MeV (the fifth channel recorded all pulses of greater amplitude than the fourth) ; the counting rates were then compared with a suitable standard.…”

“…Reference has already been made to the routine measurement of 137Cs in dried milk (Booker 1957) and to the limitations of a five-channel analyser. Despite the limited resolution the presence of other activities emitting high-energy gamma rays can be detected quite readily by the lack of agreement between the three estimates of potassium obtained from the counting rates in channels 2, 3 and 4 (channel 1 covers the 13'Cs photo-peak at 0.66 MeV).…”

Radioactive Fallout and Foods, Determination of Fallout Cesium-137 in Animal and Plant Tissues

“…It is thus one of the fallout contaminants of interest in agricultural products. Fallout Cs137 in agricultural products has been measured by bulk counting, using large scintillation crystals and multichannel pulseheight analyzers (7,2,9). This method, aside from requiring very specialized instrumentation, is subject to interference from -rays of RuRh103• 106 and ZrXb93, if they are present in a high ratio to Cs137.…”