The suspension was transferred to a 20-mL polypropylene syringe. The glass container was rinsed twice with 5 mL of 4.2% sodium bicarbonate solution, and the suspension was added to the syringe.

After that, 2 mL of 0.1 M sodium bicarbonate was mixed with the supernatant. This step was repeated twice, followed by the acidification of the sodium bicarbonate layer to pH 3 with 6 N HCl. The ...

Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States ...