Division 4.5 Preparation of calibration curve
United Kingdom
Take four 10-ml volumetric flasks and pour 1 ml concentrated nitric acid and 1 ml 5 % lanthanum solution (2.3) into each.
Pour 0, 1, 3 and 5 ml respectively of a 10-ppm calclium solution into the flasks and make up to the mark with double-distilled water.
Determine the absorbance of each solution and plot the calibration curve after subtracting the blank value from the standards.