ABSTRACT
Aqueous samples are acidi ed to a pH below 2 with either 1:1 HCl or H2SO4. Usually 5 mL of acid should be su cient for acidifying 1 L of sample. e sample measured to a volume of one liter is then transferred into a 2 L separatory funnel. e sample bottle is rinsed with 30 mL extracting solvent and the solvent washings are added to the sample in the separatory funnel. e sample-solvent mixture is then shaken vigorously for 2 min. Allow the layers to separate. If the extracting organic solvent is lighter than water, such as hexane, then it will be on the top of water. If the solvent is heavier than water then it will be in the bottom immiscible layer. e organic layer is then drained out carefully from the aqueous phase leaving a small amount of it in the water and passed through a funnel containing a lter paper and 10 g anhydrous sodium sulfate, both of which have been solvent-rinsed into a clean and tared distilling ask containing a few boiling chips. Passage through anhydrous Na2SO4 removes any trace waters present in the organic solvent extract.
