Verifikasi Metode Penentuan Timbal Secara Spektrofotometri Serapan Atom (SSA)

Summary

This video demonstrates the process of verifying and determining lead concentration in water using the HS method. It details the preparation of various lead solutions, including a 1000 mg/L stock solution, and how to create a standard series with concentrations ranging from 0 to 20 mg/L. Additionally, the script covers the preparation of spike solutions and the use of a spectrophotometer for analysis. The video walks through calibration, sample analysis, and the necessary steps to ensure accurate results in verifying lead concentration in water.

Takeaways

• 😀 The script outlines a procedure for determining lead (Pb) levels in water using photometry in a laboratory setting.
• 😀 Various materials and tools are used, including Pb(NO₃)₂, HNO₃, droppers, stirrers, glass flasks, and pipettes.
• 😀 The process begins with preparing a Pb solution (1000 mg/L) by dissolving Pb(NO₃)₂ in 1 molar HNO₃ and diluting to 50 mL.
• 😀 The 1000 mg/L Pb solution is then used to prepare a 100 mg/L Pb solution by taking 5 mL and diluting it to 50 mL.
• 😀 A standard series with concentrations ranging from 0 to 20 mg/L is prepared by further dilution of the 100 mg/L Pb solution.
• 😀 Spike solutions are created by combining 1 mL of Pb sample with 1 mL of 100 mg/L Pb solution and diluting to 25 mL.
• 😀 The script explains how to set up and calibrate the photometric instrument, including selecting the correct lamp and method parameters.
• 😀 Instrument settings for spectrophotometry include a delay time of 1 second, a timing of 1 second, and an acetylene-air ratio of 2:1000.
• 😀 Calibration of the photometric instrument is done using a linear method with a focus on obtaining results in mg/L units.
• 😀 The script concludes by explaining the testing of standard series solutions (0, 1, 5, 10, 15, 20 mg/L) followed by testing of sample and spike solutions.

Q & A

What is the purpose of the photometry lab in this script?

The photometry lab's purpose is to determine and verify the HS lead determination method in water samples using atomic absorption spectrophotometry (AAS).

What are the primary chemicals and materials used in the procedure?

The primary chemicals and materials used are Pb(NO₃)₂ (lead nitrate), HNO₃ (1 molar nitric acid), a 50 mL measuring flask, a 25 mL glass flask, a pipette (5 mL), a dropper, a stirrer, and an atomic absorption spectrometer with a Pb lamp.

How is the Pb 1000 mg/L solution prepared?

To prepare the Pb 1000 mg/L solution, 0.08 grams of Pb(NO₃)₂ is weighed and dissolved in 1 M HNO₃. The solution is then transferred to a 50 mL measuring flask and diluted to the mark with distilled water.

What steps are involved in preparing the Pb 100 mg/L solution?

To prepare the Pb 100 mg/L solution, 5 mL of the 1000 mg/L Pb solution is pipetted into a 50 mL measuring flask and diluted with 1 M HNO₃ to the 50 mL mark, followed by thorough shaking.

What is the purpose of the standard series in the procedure?

The purpose of the standard series is to create a set of Pb solutions with known concentrations (0, 1, 5, 10, 15, and 20 mg/L) to calibrate the atomic absorption spectrophotometer for accurate measurement of lead in water samples.

How is the spike solution prepared and what is its purpose?

The spike solution is prepared by combining 1 mL of Pb sample with 1 mL of a 100 mg/L Pb solution, then diluting the mixture to 25 mL with the Pb sample. Its purpose is to test the accuracy and recovery of the lead analysis method.

What steps are involved in calibrating the atomic absorption spectrometer?

The atomic absorption spectrometer is calibrated by selecting the Pb lamp, choosing the appropriate test parameters, setting the acetylene/air ratio, and entering the standard solution concentrations. The calibration curve is then generated for analysis.

What is the significance of the linear calibration method mentioned in the script?

The linear calibration method is used to create a calibration curve based on the standard solutions, ensuring that the relationship between the concentration of lead and the spectrophotometric readings is linear and reliable for accurate sample analysis.

Why is it important to rinse the beaker with HNO₃ after preparing the Pb solution?

Rinsing the beaker with HNO₃ ensures that any remaining Pb in the beaker is transferred to the measuring flask, preventing contamination and ensuring the accuracy of the final solution.

What steps are taken to test the sample solutions using the atomic absorption spectrometer?

The sample solutions are tested by analyzing them starting from the lowest concentration (0 mg/L) to the highest (20 mg/L). The readings are compared to the calibration curve to determine the lead concentration in the samples.