Determination of the Cause of a Fish Kill

Purpose:Determine the cause of a fish kill in the Clark Fork of the Columbia River, Montana.Introduction:A major fish-kill took place in the Clark Fork in 1984. Each group will receive a simulated sample of water from the Clark Fork and will determine the presence of IA and IIA metal ions as well as the concentrations of Cu2+ and Fe3+ions to determine whether the water is toxic, and if so, which ion(s) caused the toxicity. This information will be gathered using the spectrophotometer to record the emission analysis and the absorption spectroscopy. The max will be determined after looking at the graphs. The concentration range will be from 400 ppm to 60 ppm and will include 280, 200, and 120 ppm. Many of these metal ions are toxic, harmful, or otherwise unsafe. Groups should take appropriate precautions, including wearing safety goggles and appropriate clothing.

Procedure: Part 1Obtain ~1 mL of the simulated sample. Record unknown number!

Clean nichrome wire with HCl and distilled water, disposing of HCl properly.

Set up MeasureNet workstation:Turn power on, and press Main Menu.

Press Spectroscopy.

Press Emission.

Press F1 to set up scan limits, using the left and right arrow buttons to move between min and max.Set max intensity (y) as 1500.

Set min intensity (y) as 0.

Leave default settings for wavelength nm (x).

Press Display.

Go to MeasureNet spectrophotometer and enter workstation number

Zero out MeasureNet spectrophotometerCover the end of the fiber optic cable and press Zero. Cover cable until spectrophotometer reads Ready to Scan.

Clean bunsen burner of residual metal ions:Heat nichrome wire until it glows orange (hold at tip of inner blue triangle)

Plunge wire into distilled water in watch glass near the bunsen burners gas intake.

Repeat 3-4 times.

Pour ~1 mL of the simulated sample (step 1) into clean, dry watch glass.

Heat nichrome wire.

Plunge glowing orange wire in sample watch glass near the bunsen burner gass intakeWhen the flame changes color, immediately press sample.

Record color of sample in Lab Report and save scan at workstation by pressing F3, and press enter.

Turn off MeasureNet station after saving!

Part 2Obtain approximately 30 mL of both the 400 ppm Cu2+ and Fe3+ samples.

Prepare 10 mL of each of the following solutions, using the equation

(desired ppm)*10=mL of 400 ppm per 10 mL of desired concentration:400 ppm

280 ppm

200 ppm

120 ppm

60 ppm

*Show work in Lab Report for each ion and concentration.*If 30 mL of the sample is unattainable,use 5 mL and adjust equation by dividing by 2.After thoroughly mixing each solution, fill cuvettes until cuvettes are almost completely full. (Dont forget simuated sample!)

Perform absorption spectroscopy:Zero out spectrophotometer

Test and save each concentration of both Cu2+ and Fe3+

See Appendix D for more instructions.

Save each
(see below) and turn off MeasureNet system.Cu2+=01-

Fe3+=02-

Sample=030

400=-1, 280=-2, 200=-3, 120=-4, 60=-5

Dispose of sample, Cu2+ solutions, and Fe3+ solutions properly.