I am using Nanobrook haven (90 Plus PALS) to measure my nanoparticle size (micelles). I run the sample for 6 repeats. When checking the results, I get 5 consistent readings (same or very close number). However, the 6th reading gives an outlier number. How can I get six consistent repeats (taking into consideration that the sample is filtered three times after lyophilization) ? I doubted that the machine may have a problem, but I found other samples give consistent 6 readings.
Replicate readings for other samples are reproducible or consistent except for nanoparticle size measurement. If you mean the results for other nanoparticle samples it means system is fine. Check whether you are consistent with method adopted for replicate measurements.It is because the procedures are not followed meticulously. Calculate standard deviation within a given set of measurements and relative standard deviation among two or more sets of measurements made at different times.
What happens if you run the reference material (ZR5)?
What are the count rates like? Are the outliers' count rates different? Maybe you are too dilute.
Try running more repeats (e.g., for an hour).
Micelles scatter weakly. You may need to increase the run time. If I recall, the ZetaPALS software can be configured to stop the run when it thinks it has reached a steady value OR you can override that and run for your specified duration. I recommended trying that.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles