Sensitive Detection of Antifoam
According to Mark Schenerman, Ph.D., of MedImmune, “Antifoam C is widely used in the pharma and food industries, and while there are no known risks associated with its use, its presence is often monitored.”
The compound, whose active ingredient is poly-dimethylsiloxane, is a silicon-containing material used to control foaming in industrial and manufacturing processes.
Although it is generally removed by subsequent processing, quantitative demonstration of this can be a challenge. Developing a sensitive detection method has proved challenging due to its lack of spectroscopic absorbability. Elemental silicon (Si), however, can be detected using inductively coupled mass spectrometry, a sensitive approach.
“This technology has come a long way in the last 10 years,” Dr. Schenerman said. It uses an ionized gas, or plasma, and any material introduced into the plasma will itself be ionized and can be identified in the mass spectrometer. The procedure can measure Si at parts per trillion. It is widely used in trace-element identification throughout the industrial world.
MedImmune demonstrated that this approach to the quantification of Antifoam C is highly specific and reproducible. A number of different diluents and spiked solutions were monitored with a high degree of accuracy. Thus this method is suitable for determination of Antifoam C levels in production samples. It should be noted that this technique is applicable to the detection of any compound that has a unique and identifiable atom as part of its structure.