SPEKTROFOTOMETER UV-VIS THERMO-GENESYS150 | FARMASI ANALISIS - STFI Bandung

Summary

This video demonstrates the process of measuring paracetamol concentration using a UV-Vis spectrophotometer. The procedure includes preparing a stock solution of paracetamol, calibrating the spectrophotometer, and creating a standard curve with varying concentrations of paracetamol. The video explains each step, from wavelength calibration to absorbance measurement, providing clear instructions on using the spectrophotometer for accurate quantification. By the end of the video, viewers will learn how to use the standard curve to determine paracetamol concentration in an unknown sample, ensuring reliable results in pharmaceutical analysis.

Takeaways

• 😀 The video demonstrates how to measure the paracetamol content using a UV-Vis spectrophotometer.
• 😀 The equipment used includes a Thermo Scientific Genesis 150 UV-Vis spectrophotometer, micropipette, volumetric flasks, and quartz cuvettes.
• 😀 The process begins by preparing a 100 PPM paracetamol stock solution by dissolving 10 mg of paracetamol in 0.5 mL of methanol and then diluting with aquades to the 100 mL mark in a volumetric flask.
• 😀 The spectrophotometer is calibrated by performing an auto-zero step with the blank solution in the cuvette before setting the wavelength range between 200-400 nm.
• 😀 The maximum absorption wavelength for paracetamol was found to be at 243 nm.
• 😀 After determining the maximum absorption wavelength, the absorbance of five paracetamol solutions with varying concentrations (5-25 PPM) is measured to generate a standard curve.
• 😀 Before measuring the samples, the blank solution is measured to ensure accurate results.
• 😀 The absorbance of the standard solutions is measured one by one, and the data is used to establish a linear regression equation with a high correlation coefficient (R² = 0.994).
• 😀 A sample of paracetamol powder is dissolved similarly to the stock solution and its absorbance is measured at 243 nm to determine its concentration.
• 😀 The video concludes with an explanation that the results will be discussed in the next session, and the entire procedure demonstrates the application of the spectrophotometer in pharmaceutical analysis.

Q & A

What is the main objective of the video?

The main objective of the video is to teach how to measure the concentration of paracetamol using a UV-Vis spectrophotometer.

What equipment is used in the experiment?

The equipment used includes a Thermo Scientific UV-Vis Spectrophotometer Genesis 150, a Brotip Yello Tip micropipette, 10 mL and 100 mL volumetric flasks, a dropper pipette, and a quartz cuvette.

What materials are required for preparing the paracetamol solution?

The materials needed include paracetamol powder, methanol, aquades (distilled water), and ethanol.

How is the paracetamol stock solution prepared?

A 100 PPM stock solution of paracetamol is made by dissolving 10 mg of paracetamol in 0.5 mL of methanol and then adding aquades until the 100 mL mark of a volumetric flask.

What is the first step in the procedure when using the spectrophotometer?

The first step is to perform an auto-zero by inserting the blank solution into the cuvette.

What is the range of the wavelength set on the spectrophotometer?

The wavelength range is set between 200 and 400 nm.

How is the maximum wavelength for the measurement determined?

The maximum wavelength is determined by measuring the absorbance of the stock solution and identifying the wavelength with the highest absorbance, which in this case is 243 nm.

What is done if the absorbance reading exceeds the instrument’s capacity?

If the absorbance exceeds the measurement range of the spectrophotometer, dilution of the stock solution is performed, and the absorbance is measured again.

How are the calibration standards prepared for the experiment?

Calibration standards are prepared by creating five solutions with concentrations ranging from 5 PPM to 25 PPM.

What data is recorded after measuring the calibration standards?

The absorbance values for the calibration standards are recorded, and a regression equation is obtained from the data to generate a calibration curve. The correlation coefficient (R²) for this curve is 0.994.

What is done after the calibration curve is prepared?

Once the calibration curve is ready, the absorbance of the sample solution is measured at the previously determined maximum wavelength of 243 nm.

How is the concentration of the sample determined?

The concentration of the sample is determined by comparing its absorbance value to the calibration curve, using the linear regression equation derived from the calibration standards.