Anne said:I am currently doing a project on sunscreen analysis using UV Vis Spectroscopy and I am using slides to prepare my samples for measurement.My setback is how to make the samples uniform so as not to affect the transmittance and absorbance results.Any ideas on how i can successfully makes all the samples on the slides even and uniform?
The first step in preparing a sample of sunscreen for UV-Vis is to weigh out the desired amount of sunscreen and dissolve it in a suitable solvent. Next, the sample should be filtered to remove any impurities. Then, the sample should be transferred to a UV-Vis cuvette and the absorbance spectrum should be measured.
A solvent that is transparent to UV-Vis light should be used for dissolving sunscreen. Common solvents used include ethanol, methanol, and cyclohexane. The choice of solvent will depend on the properties of the sunscreen being tested.
The sample should be filtered using a syringe filter with a pore size of 0.2 microns. This will remove any large particles that may interfere with the absorbance measurements. It is important to use a clean filter for each sample to avoid cross-contamination.
Yes, sunscreen samples can be stored for future use in UV-Vis as long as they are kept in a dark, cool place to prevent degradation. It is recommended to use the samples within a few weeks of preparation to ensure accuracy of the results.
The accuracy of sample preparation for UV-Vis can be ensured by following a standardized protocol and using calibrated instruments. It is also important to use high-quality solvents and properly store the samples. Regularly running blank samples and replicates can also help to verify the accuracy of the results.