Fig. 4

Release of formaldehyde by the degradation of THF. a Schematic diagram of formaldehyde released from THF molecule. b Effect of DTT concentration on formaldehyde released from THF. The reaction mixture contained 0.5 mM THF, 50 mM Tris-HCl buffer (pH 7.5) and different concentration of DTT, and was assayed after 6 h. c Effect of different antioxidants on the release of formaldehyde from THF degradation. The reaction mixture contained 0.5 mM THF, 50 mM Tris-HCl buffer (pH 7.5) and 2 mM antioxidant after 3 h. d Formaldehyde released from THF at different pH values. The reaction mixture contained 0.5 mM THF, 20 mM DTT in phosphate buffer at different pH values