Hyaluronan, also called HA is an important component of different tissues, especially connective tissue of vertebrate animals. Thus hyaluronan is an endogenous substance which is for example found in the vitreous of the human eye as well as the human joint fluid. With the molar mass of 379,32 g/mol the glycosaminoglycan represents a rather small molecule, but this is only the monomeric form. The endogenous HA is found with different polymeric length depending on its function.
Structure formula hyaluronan
Hyaluronan is able to bind water (about six liters per gram HA) and supports the cell migration due to the expansion of the intercellular space. HA as well as its salts are used for human medicine as well as aesthetic medicine and cosmetics. HA is frequently applied for nose sprays, eye drops and moistening creams as well as injection for arthrosis (as lubricant for the joint).
The analysis of HA with capillary electrophoresis is possible using an alkaline electrolyte. For the determination of HA in complex sample matrices like creams micellar techniques should be prefered to ensure good solubility of the sample.
Hyaluronan standard solution
- Separation: MEKC
- Electrolyte: Borate-SDS, pH 9.3
- Capillary: fused silica, Bubble cell, 50 µm ID, 64 cm in total
- Injection: 10 s, 50 mbar
- Detection: direct UV, 200 nm
- Description: Hyaluronan migrates as an anion at the alkaline pH of 9,3 of the electrolyte. To ensure good solubility of the challenging sample matrix in the cream micelles were added to the solution. The PDF show the electropherogram of a hyaluronan standard solution and the UV spektrum at the peak maximum.
Hyaluronan standard solution 500 mg/l
Download: Hyaluron-Standard.pdf
Determination of the linearity of hyaluronan
- Separation: MEKC
- Electrolyte: Borate-SDS, pH 9.3
- Capillary: fused silica, Bubble cell, 50 µm ID, 64 cm in total
- Injection: 10 s, 50 mbar
- Detection: direct UV, 200 nm
- Description: The linearity of HA is checked in the range of 10 to 750 mg/ at six different concentration levels. The PDF shows five exemplary electropherograms of different HA concentrations, the calibration curve and some statistical data of the calibration.
Linearity of hyaluronan standars solutions
Download: Hyaluron-lin
Hyaluronan in eye drops
- Separation: MEKC
- Electrolyte: Borate-SDS, pH 9.3
- Capillary: fused silica, Bubble cell, 50 µm ID, 64 cm in total
- Injection: 10 s, 50 mbar
- Detection: direct UV, 200 nm
- Description: Hyaluronan is used for moistening in eye drops. Further ingredients are sorbitol and buffer solutions like citrate buffers, which can be determined with the same analysis method. The PDF shows electropherograms of two different eye drop samples. For sample preparation they were twentyfold diluted with pure water.
Hyaluronan in eye drops
Download: Hyaluron-Augentropfen.pdf
Hyaluronan in skin care products
- Separation: MEKC
- Electrolyte: Borate-SDS, pH 9.3
- Capillary: fused silica, Bubble cell, 50 µm ID, 64 cm in total
- Injection: 10 s, 50 mbar
- Detection: direct UV, 200 nm
- Description: Hyaluronan is included in several creams and masks where the binding of water leads to a plumping up effect of the skin. The PDF shows electropherograms of a skin mask and of an anti ageing serum. The samples were diluted with pure water and homogenized in an ultra sonic bath. The injections of the samples were done directly without filtration.
Hyaluronan in skin care products
Download: Hyaluron-Hautpflege.pdf