Liquid Scintillation Counting is an analytical technique which measures the activity of radionuclides in a sample by the rate of light photons emitted by a sample. By measuring the amount and intensity by which a sample emits photons, it is possible to identify and quantify the radioisotopes present in a sample.
As we all learned in chemistry 101, an atom is electrically balanced when the number of protons in the nucleus is equal to the number of electrons in its orbital cloud. When nuclei become unstable, decay takes place which is accompanied by a release of energy in the form of radiation. Since this energy is kinetic i.e., the energy of motion, the decayed particle dissipates its energy through collisions within the medium in which it occurs. During the Liquid Scintillation process, the sample containing the radionuclide is dissolved in a scintillation solution known as a “cocktail”. This cocktail consists of a solvent and a solution which is a fluor or scintillating chemical. As the decayed particles react with this cocktail, the end result is a release of energy in the form of a photon of light. When this reaction occurs in a dark enclosure such as a liquid scintillation counter, these photons can be captured by a photomultiplier tube and converted into electrical impulses. These impulses can then be measured for qualitative and quantitative analysis used to indicate which radioactive elements are present in the sample.
So, why do you need a special type of vial for this process? As you may or may not know, there are different types of formulations of glass. The original glass scintillation vial was developed by Edward C. Wheaton in collaboration with Lyle Packard of Packard Instruments nearly fifty years ago. This Wheaton “180” brand of glass used in our Liquid Scintillation Vials is unique in that it features ultra-low potassium borosilicate glass. How does the potassium level in glass affect scintillation counting you ask? Potassium (K40) is a radioactive isotope that, when present in glass, can create erroneous results in scintillation counting by causing background counts. By minimizing the potassium levels in our glass formulations, we can ensure reliable, consistent results in scintillation counting.
Wheaton’s Liquid Scintillation Vials are available in glass, HDPE with lightweight walls for increased counting efficiency, and PET. The vials can be purchased with the caps attached or with the caps packaged separately and in an assortment of different cap and liner materials.
Wheaton is currently holding a Liquid Scintillation Vial promotion. Click here more information on the promotion.