Sources of error in the channels ratio method for efficiency determination in liquid scintillation counting.
The reliability of the channels ratio method for determining counting efficiency in liquid scintillation counting was investigated. It was found that the efficiency of counting gels, cloudy samples, two-phase samples, samples in which the radioactive material was precipitating, and samples on solid supports could not be reliably determined from a normal quench correction curve. A curve constructed from external standard channels ratios was unreliable when mixing different vial sizes and sample volumes, but one constructed from sample channels ratios was not. It was also found that variation in instrument performance can result in large errors unless samples and standards are counted together. Statistical error changed relatively little within the range of ratios 0.3 to 0.8.
Department of Physiology, University of Liverpool, England.
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Neame
D002250:Carbon Radioisotopes; D011232:Chemical Precipitation; D005782:Gels; D008055:Lipids; D012015:Reference Standards; D012588:Scintillation Counting / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D012995:Solubility; D013696:Temperature; D014316:Tritium; D014867:Water
D002250:Carbon Radioisotopes; D005782:Gels; D008055:Lipids; D014867:Water; D014316:Tritium