Sample preparation of sunscreen for use in UV-Vis

  • Thread starter Thread starter Anne
  • Start date Start date
  • Tags Tags
    Preparation
Click For Summary

Discussion Overview

The discussion revolves around the preparation of sunscreen samples for analysis using UV-Vis Spectroscopy, focusing on achieving uniformity in sample thickness to ensure accurate transmittance and absorbance measurements. Participants also explore data handling and analysis techniques related to the collected results.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant seeks advice on how to make sunscreen samples uniform on slides to avoid affecting transmittance and absorbance results.
  • Another suggests using shim material between optical flats to create a uniform sample thickness, proposing a method to clamp the setup together.
  • A different participant proposes diluting the sunscreen in methanol and using a quartz cuvette to eliminate concerns about film thickness.
  • One participant reports success using a cuvette and inquires about plotting graphs in MATLAB from Excel data, mentioning the challenge of handling a large dataset from nine samples.
  • Another participant suggests exporting the Excel data as CSV to facilitate data handling.
  • Further inquiries are made about the process of performing Singular Value Decomposition (SVD) in MATLAB, with one participant expressing a lack of experience in MATLAB.

Areas of Agreement / Disagreement

Participants express various methods for preparing samples and handling data, but there is no consensus on the best approach for either sample preparation or data analysis techniques.

Contextual Notes

Participants discuss different methods for sample preparation and data analysis without resolving the effectiveness or appropriateness of each method. The discussion includes assumptions about the suitability of materials and techniques for specific experimental setups.

Who May Find This Useful

Researchers and students involved in spectroscopy, particularly those working with sunscreen analysis and data processing in MATLAB.

Anne
Messages
9
Reaction score
0
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?
 
Chemistry news on Phys.org
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?

One possibility is to use a bit of shim material (something thin) that you can clamp between two optical flats. If you have shim material that is cuttable, it would be easy to cut out a small section for your sample, put the shim on top of the bottom slide, place the sample in the cut-out, and place the top slide on top. Hold the whole thing together with tape, rubber band, binder clip, etc. Yu may need to make a channel for the excess sample to squeeze out. You can run a blank the same way.
 
Hello:
Why do you not dilute the sunblock in methanol and then read it in a quartz cuvete. That way you would not have to worry about the thickness of the film.
 
  • Like
Likes   Reactions: Borek and Quantum Defect
Thank you guys for the input.Used a cuvette and got my results.Another question is that the data collected is in excel format.I would like to plot graphs for all measurements in MATLAB but the roadblock is that its a lot of data since I did nine samples.I was told that i can use Singular Value Decomposition to reduce the dimensions.Anyone know how i can apply the SVD in my data in excel and also plot the graphs in matlab?
 
Why don't you export the excel data as CSV?
 
@Borek please guide me on how to do that.I would highly appreciate that.
 
Use Save as command and select CSV (comma separated values) as the output format. This is a simple text format with a single line being a row of the spreadsheet.
 
And how do i do singular value decomposition on the values in matlab?
 
Sorry, no experience in matlab.
 

Similar threads

UV-Vis of zinc oxide nanoparticles
  • · Replies 5 ·
Replies
5
Views
5K
TiO2 Dispersion in Water: Challenges and Solutions
  • · Replies 3 ·
Replies
3
Views
4K
What Dye Absorbs Strongly Around 490nm for UV/VIS Spectrophotometry?
  • · Replies 3 ·
Replies
3
Views
3K
Using UV-Vis Spectroscopy to determine concentration
  • · Replies 15 ·
Replies
15
Views
25K
UV-VIS Spectroscopy question
  • · Replies 3 ·
Replies
3
Views
2K
Detecting drug in ethanol solvent using UV-Vis
  • · Replies 6 ·
Replies
6
Views
3K
Partition coefficient of chlorpromazine in DMSO & pentane
  • · Replies 24 ·
Replies
24
Views
4K
How Can DSC Graphs Enhance Teaching Laboratory Experiences?
  • · Replies 4 ·
Replies
4
Views
2K
Python Applying Accelerated Raymarching to Reduce Rendering Time
  • · Replies 0 ·
Replies
0
Views
2K
Optical Tweezers: Preparing Samples for RBC Trapping
  • · Replies 4 ·
Replies
4
Views
2K