Spektrofotometer UV Visible : Penentuan Panjang Gelombang Maksimum - STFI Edukasi

Summary

This instructional video demonstrates how to determine the maximum wavelength using a UV-visible spectrophotometer (Shimadzu 1800). The presenter guides viewers through the process, starting with turning on the instrument and connecting it to a computer running the UV Pro software. After preparing the sample (potassium permanganate solution), the video explains how to perform baseline calibration, sample measurement, and spectrum scanning. The maximum absorbance peak is identified at a wavelength of 545.5 nm. The video emphasizes safety protocols in the laboratory and concludes with a reminder to maintain lab safety standards.

Takeaways

• 🔬 The video demonstrates how to determine the maximum wavelength using a UV-Visible spectrophotometer.
• 🧪 The sample used in the demonstration is a prepared potassium permanganate solution.
• 💻 The spectrophotometer is connected to a computer using UV Pro software to facilitate data processing.
• ⚡ The instrument should be turned on at least 30 minutes prior to measurement to ensure stability.
• 📊 The wavelength range for the measurement is set from 400 nm to 800 nm in the software.
• 🥼 Cuvettes must be properly cleaned and filled with either the blank (distilled water) or the sample solution.
• 🎯 Baseline correction is performed using the blank cuvette before measuring the sample.
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• 📝 The sample cuvette is rinsed with the sample solution before measurement to avoid contamination.
• 📈 After scanning, the peak absorbance is identified using the 'pick peak' function in the software.
• 🌈 The maximum absorbance for potassium permanganate is observed at 545.5 nm with an absorbance of 0.3534.
• 🛡️ Safety in the laboratory is emphasized throughout the procedure.

Q & A

What is the main objective of the experiment described in the video?

The main objective is to determine the maximum wavelength (λmax) of a sample solution using a UV-Visible spectrophotometer.

What sample was used in the spectrophotometric analysis?

The sample used was a potassium permanganate solution.

Why should the spectrophotometer be turned on 30 minutes before use?

It should be turned on 30 minutes earlier to ensure the stability and accuracy of the instrument during measurement.

What software was used to operate the spectrophotometer?

The software used was UV Pro.

Is it necessary to use a computer to operate the spectrophotometer?

No, the spectrophotometer can operate without a computer, but using software makes data processing easier.

What wavelength range was set for the measurement?

The wavelength range was set from 400 nm to 800 nm.

What type of cuvette was used and why?

A quartz cuvette (kuvet quartz) was used because it is suitable for measurements in the UV-visible wavelength range.

What is the purpose of using a blank solution in this experiment?

The blank solution, which is aquadest (distilled water), is used to calibrate the instrument and eliminate the effect of the solvent.

What is the purpose of performing a baseline measurement?

Baseline measurement is performed to set a reference point and ensure that the absorbance measured is only due to the sample.

Why is the cuvette rinsed with the sample solution before measurement?

Rinsing ensures that no residual solvent or contaminants affect the accuracy of the measurement.

How is the maximum absorbance wavelength identified in the software?

It is identified using the 'peak pick' feature in the operation menu after the spectrum scan is completed.

What was the maximum wavelength (λmax) obtained for potassium permanganate?

The maximum wavelength obtained was 545.5 nm.

What was the absorbance value at the maximum wavelength?

The absorbance at 545.5 nm was 0.3534.

Why is it important to clean the outside of the cuvette?

Cleaning the outside removes fingerprints or residues that could interfere with light transmission and affect the measurement accuracy.

What safety reminder is emphasized at the end of the video?

The importance of always maintaining laboratory safety practices is emphasized.