Acid Washing (Day One)

Students will collect and acid wash all needed glassware. A carboy of 6 M nitric acid should be available to the students as well as a large container for acid waste. Acid washed glassware should be inverted on clean paper towels to dry until the next lab period.

Standard and Sample Prep (Day Two)

A certified primary standard of 1000 ppm Pb should be available for student use. It is important that this is transferred to their 10 mL beakers and NOT pipetted from the primary standard container itself to prevent contamination. No matrix modifier is needed for this lead analysis.

The instructor will provide “groundwater” samples to each student group. This sample should be prepared in the same way as the standards to have a concentration of approximately 8 ppm using 1% nitric acid as the solvent. They should be tightly sealed and refrigerated until used.

A waste container should be provided for all standards and samples that contain lead ions. Appropriate disposal methods should be followed.

Spectrometer Setup

The spectrometer used in the lab is a ThermoElectron Solaar M6 AA. The settings are as shown below:

Spectrometer Parameters

• Wavelength: 217.0 nm
• Background Correction should be Off
• Bandpass: 0.5 nm
• Lamp Current: 75%

Flame Parameters

• Flame Type: Air/Acetylene
• Nebulizer Uptake: 4 sec
• Burner Height: 7.0 mm
• Fuel flow: 1.1 L/min

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