Fluoride in tea samples Essay Example | Topics and Well Written Essays - 250 words

Fluoride in tea samples - Essay Example A laboratory experiment was conducted that used plastic labware bottles instead of glassware because the fluoride ions have a tendency to interact with the glass especially when at lower concentrations. Its main objective was to determine the fluoride levels in various tea samples that were obtained at random. For this experiment, a stock solution of fluoride containing 2000 mg F-/L was used and prepared using a reagent grade of sodium fluoride (NaF), then diluted in a volumetric flask and stored in a clean plastic bottle. A silver chloride (Ag-AgCL) electrode was then combined with the fluoride electrode into a single unit. Both electrodes were rinsed properly and dried for use. Next step was preparation of six (6) 50-mL fluoride standards containing the 5.0 mL of TISAB concentrate and 0.1, 0.316, 1.0, 3.16 and 100.0 mg F-/L and diluted with distilled water up to 50 mL total and stored in plastic bottles. Readings were taken and recorded by immersing electrodes in each solution with re-calibration each day for the temperature. Data obtained was plotted and shown in a graph in the method and results section of this report. The tea bags sampled were boiled in 100 mL of RODI water and then cooled to room temperature and analyzed. Sampling procedure was to mix 10.0 mL of tea sample with 10.0 mL of distilled water together with an additional 5.0 mL of TISB for a total volume of 25.0 mL per sample. The last step was adding a 0.50 mL of the standard F- solution in four increments to each mixture for a total of 2.0 mL of the solution and readings were taken at each incremental addition. The sample tea bags used in the experiment were of different brands and bought at random from a supermarket. This is in line with the objective of determining the level of fluoride in tea available from commercial sources as fluoride today is a growing serious health concern. The method used is