Citrate Buffer

CITRATE BUFFER; PH 3.0–6.2, PKA = 6.40 Citrate buffer (Gomori, 1955) stock solutions: A: 0.1 M citric acid; B: 0.1 M sodium citrate. Use x ml A + y ml B and dilute to 100 ml with 50 ml DI. 0.1 M citric acid 46.5 43.7 40.0 37.0 35.0 33.0 31.5 28.0 25.5 23.0 20.5 18.0 16.0 13.7 11.8 9.5 7.2 0.1 M sodium citrate 3.5 6.3 10.0 13.0 15.0 17.0 18.5 22.0 24.5 27.0 29.5 32.0 34.0 36.3 38.2 41.5 42.8 pH 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0 6.2 PHOSPHATE–CITRATE BUFFER; PH 2.2–8.0, PKA = 7.20/6.40 Add the following to create 100 ml of phosphate/citrate buffer solution. Stock solutions are 0.2 M dibasic sodium phosphate; 0.1 M citric acid (Pearse, 1980). 0.2 M 0.1 M citrate pH Na2HPO4 (ml) (ml) 5.4 44.6 2.6 7.8 42.2 2.8 10.2 39.8 3.0 12.3 37.7 3.2 14.1 35.9 3.4 16.1 33.9 3.6 17.7 32.3 3.8 19.3 30.7 4.0 20.6 29.4 4.2 22.2 27.8 4.4 23.3 24.8 25.7 26.7 27.8 29.0 30.3 32.1 33.1 34.6 36.4 40.9 43.6 26.7 25.2 24.3 23.3 22.2 21.0 19.7 17.9 16.9 15.4 13.6 9.1 6.5 4.6 4.8 5.0 5.2 5.4 5.6 5.8 6.0 6.2 6.4 6.6 6.8 7.0