A novel instrument developed by a research group from the University of Missouri-Columbia (MU) is designed to analyze the quality of liquids using the photoacoustic effect, or the generation of sound waves after light is absorbed in a material. Drops of sea water, dairy milk, or ionic liquids, a class of molten salt, were used in the study. The scientists believe this might be the first use of this technology to analyze such small liquid samples.
The team is working to refine its recording methods and equipment to provide commercial industries with an inexpensive way to monitor the quality of liquids, such as the percentage of alcohol in alcoholic beverages, the amount of inferior oil in fraudulent olive oils, the quality of honey, and the amount of sugar or sugar substitutes in soft drinks.
Their process is as follows: A tattoo removal laser machine emits a series of brief flashes of light, each lasting about 10 nanoseconds. The light flashes travel through a fiber-optic cable wrapped on one end with paint-on liquid electrical tape. The cable’s end, submerged in the liquid, converts the laser light into sound. The sound is recorded by a microphone and the data is analyzed in real time.