Clear liquids
For various applications in the pharmaceutical, food, cosmetic, automotive and chemical industries, it is import
ant to determine the concentration exactly to ensure proper quality of the products. Since some liquids do not absorb light within the visual range, a standard absorbance measurement using a spectrophotometer will not be effective at determining the concentration. Therefore, the concentration is determined by measuring the refractive index and holding it against a standard curve.
For example, glycerol is a colorless, odorless, non-toxic, viscous and sweet-tasting liquid. It is used in a large variety of applications including as an emollient, humectant, sweetener, solvent, or antifreeze agent. Glycerol belongs to the alcohol family of organic compounds and contains three hydroxyl groups (-OH), which makes it soluble in water. It can be derived naturally and is stable under normal storage conditions and temperatures, but still requires quality control to ensure a good product quality.
Introducing clear liquid quality control with UV-Vis instruments
Conventionally a specialized refractometer has been required for the refractometric quantification of sugar. However, with the innovative SpectroCuvetteTM One, a nanosensor is installed in a cuvette, allowing quantification of sugar to be carried out in a standard spectrophotometer. Because sugar does not absorb light in the UV-visible spectrum, traditionally, spectrophotometers have been unable to quantify sugar.All that is needed is our SpectroCuvette™ One and an UV-VIS spectrophotometer for instance Shimadzu, PerkinElmer, Thermo Ficher, Mettler Toledo, VWR or similar.
Conclusion
Traditionally a specialized refractometer has been required for determination of the refractive index. However, with the innovative SpectroCuvette™ One, an optical filter is installed in a cuvette, allowing determination of the refractive index to be carried out over time in a standard spectrophotometer. This both clear and colored liquids can be measured with a conventional spectrophotometer down to 0.5 µL of sample.