Liquid Scintillation Articles
The Complete Scintillation Cocktail
Living creatures contain both hydrophobic and hydrophilic compounds, any of which may be labeled during the course of a radioactive experiment. As discussed in earlier sections, the best solvents for scintillation counting are the aromatic organics, such as toluene and xylene. Hydrophobic compounds can be counted directly in such solvents, but hydrophilic materials, which include…
Read MoreCounting Efficiency and Quenching
While the effectiveness of a scintillation cocktail may be expressed a number of ways, it is most often given as the percentage of emission events that produce a detectable pulse of photons, referred to as the counting efficiency. In other words, one way to express the counting efficiency is to take the ratio of the…
Read MoreLiquid Scintillation Signal Interpretation
A beta particle, passing through a scintillation cocktail, leaves a trail of energized solvent molecules. These excited solvent molecules transfer their energy to scintillator molecules, which give off light. Each scintillator molecule gives off only one photon on activation, (and the wavelength of that photon is characteristic of the scintillator, not the ß-particle), but multiple…
Read MoreRadioactive Emissions and the Use of Isotopes in Research
Radioactive decay occurs with the emission of particles or electromagnetic radiation from an atom due to a change within its nucleus. Forms of radioactive emission include alpha particles (α), beta particles (β), and gamma rays (γ). α particles are the least energetic, most massive of these decay products. An α particle contains two protons and…
Read MoreAssaying Discrete Samples by Liquid Scintillation Counting
Liquid scintillation counting of discrete samples is conceptually straightforward. A sample is mixed with an appropriate volume of scintillation cocktail, and the mixture is placed in an LSC vial and counted. For some samples no additional steps are required, but in many situations samples must be processed to avoid artifacts. The most common causes of…
Read MoreMechanism of Liquid Scintillation Counting
By eliminating the combustion steps needed for gas phase analysis, the introduction of liquid scintillation counting (LSC) reduced the time required to analyze radioactive samples from hours to minutes. For low energy (“soft”) β emitters, LSC offers unmatched convenience and sensitivity. LSC detects radioactivity via the same type of light emission events which are used…
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