Table
Designation Ionac C-150 Zerolit Na Ionac C-265 Zerolit 216 Ionac C-270 Zerolit 226
I.
Typical Phosphate Values of Some Cation Exchangers
Exchanger
Type Carbonaceous, mixed Carbonaceous, mixed Carboxylic condensation polymer Carboxylic condensation polymer Methacrylate copolymer Methacrylate copolymer
Capacity (Meq./Liter) Weak acid Strong acid (phosphate value) 560 100 700 100 100 950 250
1,050
0
2,560
0
2,600
CALCULATIONS
Table II. Reproducibility of Phosphate Value Determinations (3)
Concentration Salt AnhyUsed Actual drous NzQHPO~. 12H2O 2% 0.87c 3% 1.2% ,” K2HPO4 1 . . 2.5% ... 1.6%
Phosphate Value Obtained (Meq./ Liter) 725,735,725
Strong acid group capacity
Weak acid group capacity
is collected, mixed well, and 25 ml. of it are titrated against the 0.1N sodium hydroxide solution to the phenolphthalein end point. A further 50-ml. quantity is now passed through, the effluent is again collected, and a 5-ml. aliquot titrated against the standard sodium hydroxide t o the phenolphthalein end point. If this titration figure is less than 0.5 ml., the test is complete. If it is more than 0.5 ml., then further 50-ml. aliquots are added until the 0.5ml. limit is reached. Let the sum of these titration figures be B ml. The whole procedure should be repeated at least once to obtain confirmatory results. Two consecutive cycles of operation should give results agreeing to within k501,.
=
x 1000 meq./liter Total (ultimate) capacity
=
ACKNOWLEDGMENT
The writer thanks T. R. E. Kressman, Chief Research Chemist, The Permutit Company Ltd., London W. 4., England, for his kind permission to use this material with which the writer became familiar in the course of his work with that company. Thanks are also due to Calvin Calmon, Director of Research, Ionac Chemical Co., for his kind interest and permission to publish this paper.
x 1000 meq./liter
730
725 735
=
6 x 1000 meq./liter
phosphate must be interrupted several times and the bed loosened up by a very slow upward flow of the water (this must not be such a quantity as to displace any solution from the tube), or a retaining screen or retaining plug of glass wool must be inserted above the top of the resin bed and the phosphate solution passed through in an upward direction.
45.8 meq./liter
=
1.0 kilograin/cu. foot
RESULTS
Table I shows typical results obtained by this method for various resins, while Table I1 illustrates reproducibility with different strengths of both sodium and potassium salts. EXPANSION
OF
METHACRYLIC RESINS
I n the case of bead resins of the acrylic or methacrylic acid polymer type, the volume difference between the hydrogen and sodium forms of these resins is considerable. I n consequence, it is necessary during the phosphate determination, to do one of two things. Either the passage of
LITERATURE CITED
(1) Calmon, C., Kressman, T. R. E. eds., “Ion Exchangers in Organic and Biochemistry,” p. 6, 1st ed., Inter-
science, New York, 1957. (2) Helfferich, F., “Ionenaustauscher, Band I., Grundlagen” (Ion Exchangers, Vol. I., Basic Concepts), pp. 68-87, Verlag Chemie GmbH, Weinheim/Bergstr., 1959. (3) Kressman, T. R. E., The Permutit Co. Ltd., London, England, private commpications, 1946. (4)Kunin, R., “Elements of Ion Exchange,” p. 64, 1st ed., Reinhold, New York, 1960. (5) Kunin, R., “Ion Exchange Resins,’’ p. 341, 2nd ed., Wiley, New York, 1958. (61, Nachod, F. D., Schubert,,,J., eds., Ion Exchange Technology, p. 205 1st ed., iicademic Press, New York, 1956. RECEIVEDfor review October 23, 1961. Accepted January 11, 1962.
Gas Chromatographic Determination of Absorption Coefficients and Tensions of Gases in Solution BRUCE E. JAY, RUSSELL H. WILSON, VIRGIL DOTY, HARLAN PINGREE, and BRYAN HARGIS Department o f Internal Medicine, University of Texas Soufhwestern Medical School, and Research Department, Veterans Adminisfration Hospital, Dallas, Tex.
b A gas chromatographic method for resolving mixtures of inert and chemically active biological and experimental gases in solution is described. Partial pressures of mixtures of inert gases in solution can b e measured and absorption coefficients for nitrous oxide in distilled water and in whole blood are given. The method is accurate and has several advantages over the Van Slyke manometric method. 414
ANALYTICAL CHEMISTRY
T
HIS PAPER presents a gas chromatographic technique for determining gas tensions and quantitating physiological and experimental gases in solution. Inert gases are commonly utilized to quantitate cerebral blood flow, pulmonary capillary blood flow and volume, cardiac output, and other physiological functions. Previous papers (6, 14, 16) have described the basic design for a gas chromatographic
apparatus for analysis of respiratory gases, physiological blood gases, and mixtures of experimentally inert gases. There is a paucity of data in the literature regarding absorption coefficients of many of the more common gases used for physiological research. METHODS
The Beckman GC-2A gas chromatograph was modified as shown in Figure
J
FLOW B U R E T T E
M
D
L E
F-'
Figure 2.
Diagram of cuvette
A.
Figure
I,
Helium outlet 8. Drying tube C. One-way cleaning stopcock D. Three-way stopcock for admitting reagents and samples E. Magnetic stirring bar F. Fritted-glass diaphragm G. Ball valve joint H. Capillary pipet 1. Teflon Swagelok connector 1. Polyethylene tube connector K. Toggle valve I. Quick-connect for vacuum, compressed air and atmospheric pressure M. Common chamber for three toggle valve connectors N. Magnetic stirring apparatus
Modified gas chromatographic apparatus
1. A bypass was installed in the chromatograph to insert the cuvette (Figure 2) and drying tube in the carrier gas line preceding the column. This was accomplished by using two toggle valves and two tees. Swagelok quick connect fittings were used to facilitate connecting and disconnecting the cuvette. A Brown recorder and a Perkin-Elmer integrator u-ere used to
record and integrate the output of the apparatus (Figure 3). This analytical cuvette was manufactured by Dallas Radionics, Dallas, Tex., to be used as a n integral component of the apparatus. The quantity of blood delivered by the pipet was essentially the same as t h a t of distilled water. A standard method was used to calibrate the pipet. It was filled with distilled water a t a
Table
I.
known temperature. The water was delivered into a weighing vessel. The volume was calculated using the known density of water a t the temperature of the water. The same procedure was repeated for blood. The density of normal blood containing 14 grams of hemoglobin per 100 ml. was used. This procedure was repeated 10 times
Absorption Coefficient and Tension Data
Vol. 7 0
Tension (Mm. Hg) In gas phwe In liquid phase 1.
2. 3. 4. 5.
6.
7. 8. 9.
10. 11. 12. 13. hleaii
78 3
35.60 98.68 74.89 36.15 65.48 47.86 93.70 46.94 99.98 96.93 94.16 102.18 109.65 77.1
106.4 108.0 106.2 106.5 109.5 107.4 108.4 108.4
106.4 108.7 102.6 112.3 111.2 106.0 105.2 120.2
34 30
96.58 69.60 43.84 68.44 46.20 102.36 54.45 104.61 102.18 80.37 106.50 108.40
Absorption Coefficient VOl. Chromatograph Chromatograph Whole Human Blood 0.428 1.93 0.421 5.35 0,443 4.06 0.339 1.96 0.395 3.55 0.427 2.60 5.08 0.377 2.54 0.355 5.42 0.393 5.26 0.390 0.482 5.10 5.54 0.396 5.91 0.417 4.18 0.405 Distilled Kater 0.423 5.92 0.426 6.05 0.408 5.72 0.446 6.24 0.430 6.19 0.418 5.90 0.410 5.86 0.470 6.70 0.418 5.86 0.398 5.56 0.426 5.96 0.425 6 .OO
Van Slyke without Correction for Unextracted Gas
Theoretical Values Vol. 70 of N20 in Solution
5.73 4.39 3.17 3.85 2.90 4.93 2.59 5.75 5.55 5.12 5.38 5.44 4.34
1.49 5.40 4.14 2.99 3.63 2.73 4.64 2.44 5.42 5.23 4.83 5.08 5.12 4.09
1.86 5.24 3.77 2.38 3.71 2.50 5.55 2.66 5.70 5.57 5.29 5.77
5.38 5.46
5.06 5.13
5.77 5.85 5.76 5.77 5.94 5.82 5.88
70
Van Slyke 1.58
...
...
5.38
5.06
5.51
5.18
5.34 5.16 5.42 5.50 5.02 4.98 5.32
5.04
5.85
5.09 5.17 4.72 4.68 5.10
5.88
4.30
5.88
5.77 5.75 5.76 5.81
VOL. 34, NO. 3, MARCH 1962
415
: ( 3 inches A l u m ~ n o l 6 Ft Silico Gel 250 M i l l ~ a m p e r e s
Column
Table II. Summary of Absorption Coefficients for Nitrous Oxide Taken from Literature 0.412 (6) Nz0 (blood 36-37' C.) NzO (blood 37.5' C.) = 0.416 (8) NzO (blood 37.5' C.) = 0.417 ( 1 2 ) N20 (water 0" C.) = 1.279 ( 4 ) N20 (water 10" C.) = 0.876 ( 4 )
NzO (water 20" C.) N 2 0 (water 25' C.) N 2 0 (water 30" C.) N 9 0 (water 40' C.) NiO (water 50" C.j N20 (water 13' C.) N 2 0 (water 20' C.) N 2 0 (water 25' C.) NzO (water 25" C.) N ~ O(wat,er 30" c.j
= = =
Current Carrier Gos F l o w Rote Ternperoture Sample Sire
416
,
' j
X 0 0
X
-
o .19
0.7080 N.S.
\-an Slyke with Correction Factor (6) Vol. '0 .Significance 1 0 021 p O .04 4~0.055
5.8. S.S. p
