Liquid scintillation counting
Counting efficiencies under ideal conditions is about 30% for tritium. Tritium is a low-energy beta emitter. It is nearly 100% for phosphorus-32 (32P). Phosphorus is a high-energy beta emitter. Some chemical compounds and highly colored samples can interfere with the counting process. This interference is known as "quenching". It can be overcome through data correction or through careful sample preparation. 32P can also be counted in a scintillation counter without the cocktail. This technique is known as Cherenkov counting. It relies on the Cherenkov radiation being detected directly by the photomultiplier tubes. Cherenkov counting in this experimental context is normally used for quick rough measurements.