Glycerol is used in various industries as a moisturizer, a thickener, as antifreeze or as a precursor for explosives. Its quality as well as its concentration in solution can be determined by using refractometry.
Glycerol - the widely used alcohol
Propane-1,2,3-triol, commonly known as glycerol, is a simple trivalent, non-toxic polyol and used in various applications and industries:
• Sweetener, thickener, solvent or humectant in the food and beverage industry (food additive E422)
• Antifreeze agent (for proteins/enzymes) or mounting medium for microscopy in scientific research
• Antifreeze agent in the automotive industry
• Laxative in medical care
• Ingredient of hand creams and lotions in the cosmetic industry
• Precursor for dynamite in the explosives industry
Using refractive index measurement the concentration of binary aqueous glycerol solutions can be indirectly determined.
The Abbemat refractometer family from Anton Paar
Conventional determination of the glycerol content in water is done by titration, which is a time-consuming process. Furthermore, glycerol is hygroscopic and, depending on the time of the measurement, this may lead to incorrect measurement results. An Abbemat refractometer from Anton Paar directly shows the glycerol content in water (g /100 g) within seconds. The built-in Peltier temperature control ensures a temperature accuracy of up to ± 0.03 °C. The hygroscopicity of glycerol can be diminished by using a magnetic cover or a flow cell for sample filling.
The glycerol content can be determined with an accuracy of up to ± 0.02 g/100 g either at 20 °C in the range of 0.0 g to 99.8 g/100 g or at 25 °C in the range of 0.0 g to 10 g/100 g.
Other relevant instruments
Using a density meter from Anton Paar the glycerol content of aqueous solutions can also be determined.
Good to know
Anton Paar Abbemat refractometers are ideal for determining the glycerol content in aqueous solu-tions at 20 °C, and also at 25 °C in the range from 0.0 g to 10.0 g/100 g.