Complexometric Titration Experiment

Despite following rigorous experimental procedures, there are limitations that exist, but were not addressed due to insufficient time and limited resources to carry out the experiment. Firstly, varying the length of boiling might not be the best method to determine the amount of calcium ions. If time permits, I could perhaps investigate other variables such as pH, surface area and concentration and their effect on calcium leaching. Moreover, I could also use other types of fish soup stocks and compare to determine which soup has more calcium in it. Lastly, I have purchased “cleaned” anchovies from the supermarket to carry out this experiment, where the head and bones are removed as opposed to using whole anchovies found at hawker stall. The source of calcium present in “cleaned” anchovies is significantly
It affects the titrant value because the end point of the complexometric titration is determined by what I perceived as; therefore I should use a colorimeter or other computerized measurement devices instead. Lastly, there was a large amount of hydroxy naphthol blue indicator (HNB) being used for complexometric titration. The HNB indicator affects the volume of solution and hence the concentration in the solution due to the large volume of indicator added. In order to rectify this, I could have used a more concentrated HNB indicator to possibly reduce the amount of indicator required to see a colour change.The aim of this experiment was to determine the optimum boiling time for maximum amount of calcium to be leached effectively from 100 grams of anchovy into a fixed volume of water. By comparing both methods of determining the amount of calcium — complexometric titration and UV-Vis spectrophotometry — the UV-Vis spectrophotometer is more reliable as it is more precise and accurate than titration since it is automated machinery, and hence human error will be negligible in this