Calculate and prepare the necessary volume of 0.1 M NaOH that will be sufficient for all the solutions. Using NaOH pellets, prepare a 100 μg/ml (ppm) vanillin stock solution in 0.1 M NaOH using a 50 volumetric flask. Standard solutions ranging in concentration of 8, 6, 4, and 2 μg/ml need to be prepared. Prepare these solutions from your stock solution in 50-ml volumetric flasks, diluting with 0.1 M NaOH