The Spectrophotometer: A demo and practice experiment

The spectrophotometer is an instrument used to measure the effect of a sample on a beam of light. We can learn a lot about a substance by studying the way it interacts with light.

In this video, we'll demonstrate how to use a spectrophotometer to perform a basic experiment: determining the absorbance spectrum of red food coloring.

Included in the video is a short animation that illustrates the inner workings of a spectrophotometer.

Special thanks to Joe Issa and the Gaston College Biotechnology department for helping to make this video.

[wheresjohn]

very relaxing review before a lab practical

[BrennanDemarest]

Excellent video. Clear cut and well filmed.

[athiramalukilikood]

Thankyou so much, today is my practical examination, and it was really really useful one😍

[amailyakter]

Thank you so much for such an effective demo, I got the idea of how to use this machine

[jamalfareedi]

One of the best review of Spectrophotometer in lab

[vahidmirkhani]

6:07
What does this plot mean? What's our interpretation?
As you can see, the absorbance is relatively high for wavelengths below 600, but 600 above is not absorbed and hence, transmitted.
So the photons reaching your eyes from going through this solution, mostly have wavelengths between 600 and above and hence, the red color.
I hope this helped a bit.

[theoryofeverything]

very nicely explained and the content is so smooth and crisp :)

[davidmonroy]

How do you determine the wavelength that should be used? can it be a constant, and keep it the same for all my samples?

[binbinky]

best explanation out there on how to use it. Thank you!

[tinaishemachida]

could have never found a better explanation than this yohhhh!

[A_NILAVIDILAUTAMI]

Hi, this is a very interesting video and easy to understand. I'm currently a second year pharmacy student, and I am learning about Spectrophotometer. Can I use this video for my college project? I'll give BioNetwork some credit or acknowledgement in my video. Thank you so much, stay safe and healthy!

[ChadCarney-hudu]

Now I have a way to measure if an increase/decrease of algae occurred in a sample of gymnodinium!

[The_Bees_Knees]

have a bio lab practical tomorrow, easily learned how to use it more by watching this video. thanks!!!! :)

[kusalseven]

Imagine working in a lab full of these retro style equipments 😌

[토토로솔]

what is the purpose of using blank solution?

[thainguyen]

That's awesome! It would help me a lot for my experiment next week :D

[rrbuff]

I am not totally sure of your question here. The sample concentration is irrelevant for this activity. If you plot wavelength on x axis (380, 405, 430 ) versus the measured absorbance on the y axis you will find the wavelength of maximum absorbance, called lambda max. Each color has its own lambda max. That is the goal for this particular lab.

[vinhluong]

Why does transmittance of a blank have to be adjusted to 100% before recording the transmittance (or absorbance) of sample at any wavelength?

[laraibfatima]

Sir I have a question ⁉️
1.If you tell the transmitted light in %....then absorbed light must be in you taught absorbed in (nm) and transmitted in %
2..if 10% is transmitted then 90% should be absorbed or used anywhere else?

[oldboy]

Relaxing demonstration with fine video shot