13. DIFFUSION COEFFICIENTS AND PERMEATION COEFFICIENTS 



D = "true" diffusion coefficient in sq cm/min ( f^ = -O-zr — 5-); c = concentration in ml gas (STPD) dissolved per ml 



? t a x'^ 



liquid; t = time in min; x = distance in cm. D' = permeation coefficient in sq cm/min/atm: volume of gas {ml, 

 STPD) diffusing per unit lime (min), area (sq cm), and thickness (cm), if the difference in partial pressure of the 



diffusing gas is 1 atm in the direction of the gas flow. D = , where a is the Bunsen solubility coefficient, ml gas 



a 



(STPD) dissolved per ml liquid at a partial pressure of 1 atm. The temperature coefficient of D in the range 



15-40°C is in most cases nearly 2% °C [1,2], and temperature coefficient of D' nearly 1% per oc in the same 



range. [ 3] 



Part I: O^ AND CO^ IN VARIOUS FLUIDS AND TISSUES 



Unless otherwise stated, values of D and D' were recalculated from data in the references, with the aid of solubility 

 coefficients given in these tables. 



Substance 



lAT 



Temp, °C 



"TbT 



D X 10"* 



lev 



TdT 



X 10' 



"TeT 



Reference 



TfT 



Oxygen 



Q serum 



III Solubility of O2 at 25°C was calculated from the value for whole blood [5] and the ratio 7— r — . . ,» 0.908 [4]. 



IZl For the solubility coefficient of O2 in 8% serum protein solution and in 8% methemoglobin solution, the value for 

 serum was taken (4]. HI For the solubility coefficient of O2 in 30% methemoglobin, the value for erythrocytes [4] 



was taken. /4/ Solubility of whole blood was used [4,5] as the partition coefficient ( — rr — j-) for most gases is too 



close to 1.0 [9]. /5/ Value for D' is calculated from 9 E, assuming a temperature coefficient for D' of 1% per°C[3]. 

 Ibl Value for D' is calculated from 11 E, assuming a temperature coefficient for D' of 1% per oC [3]. /7/ Value di- 

 rectly determined. /8/ Value for D is calculated from 17 C by assuming a rise of D by 2% per °C [2. 1 1 ] . 



Contributors : (a) Bartels, H., (b) Opitz, E. 



References: [l] Carlson, T., J. Am. Chem. Soc. 33:102, 1911. [2] Gertz, K. H., and Loeschcke. H. H., unpub- 

 lished. (3] Krogh, A., J. Physiol., Lond. 52:391, 1919. [4] Sendroy, J., Jr., Dillon, R. T., and Van Slyke, D. D., 

 J. Biol. Chem. 1^:597. 1934. [5] Dill, D. B., and Forbes, W. H., Am. J. Physiol. ^1:^85, 1941. [6] Kreuzer, F., 

 Helvet. physiol. pharm. acta 8:505, 1950. [7] Kreuzer, F., ibid 9:388, 1951. [8] Pircher, L., ibid 10:110, 1952. 

 |9) Kety, S. S., Pharm. Rev., Bait. 3:1, 1951. [10] Daynes, H. A., Proc. Roy. Soc, Lond., A 97:286. 1920. 

 [11] Carlson, T., J. Am. Chem. Soc. 33:1027, 1911. [12] Hafner, G., Wied. Ann. Physik. 60:134, 1897. (13) Fenn, 

 W. O., Am. J. Physiol. 85:207, 1928. [14] Wright, C, J. Gen. Physiol. r7:652, 1934. [15] Glazebrook, R. T., 

 "Dictionary of Applied Physics, " vol V, London: MacmiUan Co., 1923, 



10 



