Quantitative Analysis of Potassium Permanganate by Spectrophotometric
Methods
Student Contributors: Abaryan, D.; Albino, D.; Bonilla, J.; Escalera, E.; Hernandez, J.E.; Manjikian, A.; Mills, M.; Orr, E.; Park, A.; Reyes, S.; Robles, K.; Ryu, C.; Suh, S; Zielke , C.A.
Faculty: Boan, T.
Results
Discussion
Abstract
Absorbance vs Time
Various Water Sources: 0.00016 M KMnO4
0,35
0,3
0,25
Absorbance (lmax)
Possible factors affecting absorbance readings of potassium
permanganate solutions were investigated. Parameters studied include
potassium permanganate precipitate age (as determined at time of purchase),
pH, light exposure, and water sources. Various concentration of potassium
permanganate solutions were prepared to test each parameter. Their absorbance
was measured in timed intervals. While our data points toward water sources as
the main culprit in solutions degradation, further studies are underway to rule
out other factors.
Three different concentrations (KMnO4) were analyzed with
spectrophotometry.
KMnO4 was found to degrade under all
concentrations. Non-volatile organic compounds were ruled out as
possible culprits. Other oxidizable ions account for some of the
degradation. Micro-organism(REF) and MnO2(REF) stand to also be
part of the degradation process. Currently investigations are underway to
isolate the possible causes (know how one could check for MnO2 and
micro-organisms in experimentation) of degradation. The kinetics of the
degradation are consistent with first order rates.
0,2
Ultra-Pure Water
Absorption of KMnO4 with Deionized Water
Deionized Water
0,15
0,3
Environmental Water
0,1
0,25
0,05
0
0
20
40
60
80
100
120
140
Time(hours)
Figure 2 – Time dependent absorption (lmax = 523 nm) of three different water
sources.
Methods
Absorbance (lmax)
0,2
0.00016 M
0,15
0.000064 M
0.000032 M
0,1
0,05
Conclusion
0
0
20
40
60
80
100
120
140
Time (hours)
The absorbance of potassium permanganate solutions were measured on 3
different Spec20 spectrophotometers1 (lmax = 523 nm). Three KMnO4
concentrations (0.00016 M, 0.000064 M, 0.000032 M) were studied in a 200
hour time frame. Control groups (water sources) were also analyzed.
Figure 5 – Time dependent absorption (lmax = 523 nm) of three different KMnO4
concentrations (0.00016 M, 0.000064 M, 0.000032 M ).
Absorbance vs Time
Various Water Source: 0.000064 M KMnO4
0,14
0,12
Absorbance (lmax)
0,1
Absorbance Spectra
0,45
0,08
Ultra-Pure Water
Deionized Water
0,06
Environmental Water
0,04
0,4
Acknowledgements
0,35
0,02
0,3
Absorbance
Preparing stable KMnO4 solutions requires a multi-step
approach. Initially the solutions must be made and the natural
degradation (based on oxidizable ionic content and / or micro-organism
present) allowed to occur. The aged solutions should then be filtered to
remove MnO2 so that any further catalyzed (MnO2) degradation does
not occur.
0,25
Natural Log of Absorbance vs Time
0
0
0
0,2
20
40
60
80
100
120
140
Time (Hours)
-1
0,15
0,1
-2
Figure 3 – Time dependent absorption (lmax = 523 nm) of three different water
sources.
0
400
450
500
550
600
650
-3
Ln(A)
0,05
700
Wavelength (nm)
Ln(A) Ultra-Pure Water
-4
Ln(A) Deionized Water
We would like to thank Professor Terry Boan and Glen
Baghdasarian, PhD, for supporting and guiding us throughout our
research experience.
Also, thank you to the Director of the LACC STEM Pathways,
Jayesh Bhakta, Ph. D. for supporting and funding our science research.
Ln(A) Environmental Water
Figure 1: Determination of lmax using a Spec20 Photometer
-5
-6
Absorbance vs Time
Various Water Source: 0.000032 M KMnO4
0,06
References
-7
-8
0,05
0
20
40
60
80
100
120
140
Various Water Sources
Absorbance (lmax)
Time(hours)
0,04
Figure 6: Constant with 1st order. ln[A] = -kt + ln[A0]
0,03
Ultra-Pure Water
Environmental Water
Deionized Water
0,02
Ultra-Pure Water – Purchased from RxBiosciences.
Environmental Water –Collected the faucet from during the Venture County
Fire.
Deionized Water – Collected from Los Angeles City College faucet at before
and after the installation of new filters.
0,01
0
0
5
10
15
20
25
30
35
40
45
50
Time (hours)
Figure 4 – Time dependent absorption (lmax = 523 nm) of three different water
sources.
(1) Machines Used: Spectronic Unicam. 333183, (machine 2), (machine 3)
(2) Hamada, Y. Z.; Makoni, N.; Hamada, H. Electronic J Biol. 2016, S:2, pp 6–9
(3) Ladbury, J.W.; Cullis, C.F.Chem. Rev., 1958, 58, pp 403–435
(4) Huang, K.C.; Hoag, G.E.; Chheda,P.; Woody, B.A.; Dobbs, G.M. Environmental Engineering
Science. 1999, 16. pp 265–274
(5) Waldemer, R.H; Tratnyek, P.G. Environ. Sci. Technol., 2006, 40, pp 1055–1061
(6) Ruiping, L.; Huijuan, L.; Xu, Z.; Jiuhui, Q.; Ran, Z. J. Hazard. Mater. 2019, 176 pp 926–931
(7) Los Angeles County Water Works Districts. Annual Quality Report. 2013, pp 1–4.
https://dpw.lacounty.gov/wwd/web/Documents/Water%20Quality%20Reports/kagel20
13.pdf
(8) Gates-Anderson, D.D.; Siegrist, R.L.; Cline, S.R. J. Environ. Eng. 2001, 127, pp 337–347
(9) Thanabalasingam, P.; Pickering, W.F. Water, Air, Soil Pollut. 1985, 29, pp 205–216
(10)Davis, C. A. Earthquake Spectra. 2014, 30, pp 1487–1509
(11)Moghaddam, A.Z.; Gwilym, J.R. Fuel Sci. Technol. Int. 1984, 63, pp 653–656
(12)Los Angeles Department of Water & Power. 2016 Drinking Water Quality Report. 2016,
pp 2–11.
file:///C:/Users/Courtney/Downloads/2016%20Drinking%20Water%20Quality%20Re
port%20FINAL.pdf