Week 6: Method Comparison

This week I tried another method of making manganese ligands. It involves combining manganous sulfate (MnSO₄) with the sodium version of a ligand, such as sodium pyrophosphate or sodium citrate, and then adding potassium permanganate (KMnO₄). I was able to make manganese citrate and pyrophosphate this way, but the reaction did not work for EDTA.  After six weeks of making and testing manganese ligands, I have several different methods that work for making manganese citrate and manganese pyrophosphate. I wanted to compare the yields and reactivity of the various methods to see which one worked the best. Manganese citrate has been made by combining sodium citrate with manganese acetate, by adding potassium permanganate to citric acid, and by adding potassium permanganate to manganous sulfate and sodium citrate. I calculated the concentrations of those solutions, diluted them to equalize the concentrations, and then measured the absorbance after adding leucoberbolin blue (LBB). I also compared the three ways I have made manganese pyrophosphate from sodium pyrophosphate: with manganese acetate, with manganous sulfate and potassium permanganate, and with manganese chloride and potassium permanganate. On Wednesday I started making manganese oxides, a process that takes several days. After combining the reagents, the solution has to be washed, shaken for an hour, and centrifuged for twenty minutes 6 times with a sodium chloride solution and 10 times with water.