The
gas liquid chromatographic of extracts of biological fluids containing analgesic drugs is illustrated in Figure 3. 'The retcnt,ion data for free niorphine (unhydrolyzed) and total morl)hine (acid hydrolyzed) were obtainrd from the 3 P.M. and 8 .4.51. urine samples of the 1 niorl)hine as de Little, if any, interference from urinary or plasnia constituents were present in the unhgdrolyzed extracted samples. Ho~vever,acid hjdidysis of the urine as 1)ert'oriiied tmoobtain total morphine does /)resent some difficulties in gas chromatography due to the extraction of urinary constituents which tend to break down following hydrolysis and appear. as extraneous peaks. Several cst rancxus peaks appeared during the formation of acetates and propionates of mori)hine on the column. This kind of intcrirwnce does not prevent the use of the gas chromatographic technique on hydrolyzed extracts of biological materials, but does require adequat,e cont,rols caoiisihting of extract:: of known normal biological fluids and tissues to be run concurrently with the unknon-n samples:. Since some variation in the control material might be expected, it is advihnble that co-gas rhromatography be 1)erforinecl. by simply adding the suspected drug to t>hebiological sample and rc,chroiiiato~rai,hiIi~. Gas chro-
matographic analysis of free anti esterified derivatives of several analgesic drugs from h>iman tihsue extracts did not present difficulties. ACKNOWLEDGMENT
Grateful acknowledgment is made to Leo ;1. I'irk, Hoffmann-La Roche, Inc., for the iminoethanophenanthrene conipounds, to 11. J. Levenstein, Endo Laboratories, Inc., for tlihydrohydroxyniorphinonc~and dih?.droc.odeinone; to Karl Pfister, llerck, Sharp & I h h m e Research Laboratories, for et,hylmorphine; and to the Clinical Chemistry Section a t St. Joseph Hospital, Lexington, Ky., for samples cf human plasma and tissues. LITERATURE CITED
(1) hiders, 31. W., Xlannering, G. J., A N A L .CHEM.34, 730 (1962). (2) Bradford, L. W., Brackett, J. W., Jfzcrochitn. A4ctw 3, 332 (1958). (3) Brochrnann-Hanssen, E., Svendsen, A . B., J . Pharm. Sci. 51, 1095 (1962). (4) Clarke, E. G. C., H u l l . .\-arc. 11, 27 (1959). ( 5 ) Clarke, I;. C:. C., Williains, XI,, / b i d . , 7, 33 (1955). ( 6 ) Cochin, J., Daly, PV. J., Experientia 18, 294 (1962). ( 7 ) Coggeshall, S . O., (ilassner, A. S., Jr., J . A m . ( ' h e m . Soc. 71, 3151 (1040). ( 8 ) Erhlich-Rogoziiisky, S., Cheronis, X. D., J/icrochem. J . 7, 336 (1963). (9) Farmilo, C. G . ) Levi, I)., Oestreicher,
10) Farmilo, C. G., Oestreicher, P. Ill. L., Levi, L., /bid.,6, 18 (1954). 11) 'Genest,,dK., Farmilo, C. G., / b i d . , 11, 20 (1959). 12) Goldbaurn, L. R., Kazyak, L., J . Pharinacol. Ezvl. Therav. 106. 388 (1952). 13) Kazyak, L., Knoblock, E. C., Asar,. CHEZI.35, 1448 (1963). 14) L1oyd;IS. A,, Fales, H. XI., Highet, P. F., Vanden Heuvel, W.J. A,, M'ildman, \V, C., J . .Am. Cheni. Soc. 8 2 , 3791 (1960). (1.3) lIannering, G. J., Jlixon, -4.C., Carroll, S . V., Cope, 0 . B., J . Lab. Clin. Jfed. 44, 292 (1954). (16) Sakamura, G. R., R d l . S a r c . 12, 17 (1960). (17) Oestreicher, P. M. L., Farmilo, C. G., Levi, L., [bid.,6, 42 (1954). (18) Parker, K. I)., Fontan, C. R., Kirk, P. L., ASAL.CHEM.35, 346 (1963). (19) Sobolewski, G.) Sadeau, G,, ("/in. Chetii. 6, 153 (1960). (20) Stahl, E,, Schroter, G., Kraft, G,, Renz, R., Pharviazie 11, 633 (1956). (21) Stewart, C. P., Stolnian, A , , eds. "Tosicology," Vol. 2, Chap. 7 , Academic. Press. Sew York. 1961. (22) Woods, L. A,, Cochin, J., Fornefeld, E. J.,-McZlahun, F . G.,Reevers, M. H., J . Pharmacal. Espl. Therap. 101, 188 (1951). RECEITEDfor review March 23, 1964. .kccepted June 29, 1964. Presented at 26th Annual XIeeting of Comniittee on 1)rug Addiction and Xarcotics, Sational Academy of Sciences, Xational Research Council, Washington, 1) C., February 1964
Separation and Analysis of Nonylphenoxy Polyethylene Glycol Ether Adducts by Programmed Temperature Gas Chromatography HERBERT G. NADEAU, DUDLEY M. OAKS, Jr.,l W. ALAN NICHOLS, and LAWRENCE P. CARR Central Analytical Research Services, Olin Mathieson Chemical Corp., New Haven 4, Conn.
b A gas chromatographic method has been developed for the separation and determination of component compounds (adducts) in nonylphenoxy polyethylene glycol ethers. Products containing up to 10 moles of ethylene oxide have been studied. The procedure allows for the separation of eight adducts and has been made quantitative for the first five in the nonyl phenol ethylene oxide series. The method utilizes dibutyl fumarate as an internal standard. Analysis of several products possessing different ratios of ethylene oxide to nonyl phenol shows relatively good agreement of adduct distribution with theory based on a Poisson function.
T~;:YY)~
of ethylene ha. been eshaustively ,studid by Flory ( I ) , and it ha$ been shown that the reaction products t:'I"oxYL.krrLoS
1914
ANALYTICAL CHEMISTRY
should vary in molecular size in proportions approaching a Poisson function. Work done by Mayhew and Hyatt (3) has demonstrated that the ethoxylation of nonyl phenol results in a mole ratio distribution of products (adducts) simulating a Poisson curve in a manner analogous to polyosyethylene glycols. The work of Miller, Rann, and Thrower (5) on the reaction between phenol and ethylene oside further substantiates a Poisson distribution of products. Later work by von Tischbirck ( 6 ) on alkoxylated phenols demonstrated that the distribution of adducts was to a great extent dependent ulmn the catalyst system em1)loyed. Fractionation of alkylphenoxy polyethylene glycol ether (SPEO,) compounds is tisually accom1)lished by both molecular and conventional distillation; however. the fractions obtained are not usually [lure, and the woik is tinie-con-
suming. By such methods, fractions having an average molecular weight of about 500 (KPEO,) ran be obtained. 13eyond this point, thermal degradation takes place. Fractionation of the molecular adducts of octyl phenol polyoxyethylene glycols consisting of 9.7 ethylene oside units has been accomplished, employing solution chromatography on silicic acid columns ( 2 ) . This work involved the separation of adducts by solvent elution, giving rise to fractions which were quite pure. The procedure is, however, tedious and to some extent depends upon weighted fractions for quantita: tion. In studies involving catalyst evaluation and kinetics, where it is desirable to follow the ethosylation of a phenol Present address, Wilkens Instrument B Itese;Lrc.h, In? , Walnut Creek, Calif
:CIS
F
5-mols 4-mole
I
3-mole
1
4-mo1e 3-mole
A
-
4x
rt
2x
Retention Time
L
Figure 2.
Polytergent B-200, 6-mole NPEO adduct
Retention Time Figure 1.
Polytergent B- 150, 4-mole NPEO adduct
with resllect to the distribution of products formed, it i3 neces,*ary to have a method which will ral)idly determine the various adducts. The potentialities of high-temperature programmed gas chromatogral)hy were considered. l l i k kelsen and Reek ( 4 ) showed qualitatively that a separaiion of adducts of a nonyl phenol ethylene oside could be obtained by 1)rograinmed gas chromatography, but did 110 work to assign peaks nor to develop a quantitative method. The method which is reported here relates to the separation and determination of nonyl phenol-ethylene oxide adducts ranging in molecular weight up to 600, corresponding to about an eightmole adduct. The procedure should be equally suited to other polymer systems where determination of high-boiling similar com1)ounds is #desired. EXPERIMENTAL
Apparatus and Reagents. F & AI AIodel 300 programmed-temperature gas chromat,ograph; 1)ow Corning Silicone SE 52 column substrate; Gas Chrom-Z, 80-100 mesh, as received froni hpl)lietl Science Laboratories; Igepal 210. obtained from General ;\niline and Film Corp. Analytical Conditions. Column :
1-meter 2'3& wt./'wt. SE 5 2 on Gas Chrom-Z, 80-100 mesh, inch o.d. aluminum. Temperature prograin: 110" to 390" C. a t 18" C.per minute. Injection port, 350" C.;carrier flow, helium 59.5 ml./'minute a t 110" C . ; detector current, 180 ma., hot wire; block temperature, 300" C.; sanilile size, 7 PI. (sample in CCI,). Procedure. Since many of t h e commercial products are compounds containing adducts of higher molecular weight than can be eluted hy the gas chromatographic method, an internal standard is used. I t was found t h a t dibutyl fumarate is nearly ideal, since it elutes without causing interference with a n y significant peak. Samples are prepared for anal) adding a known \\eight of reagrnt grade dibutyl fumarate (DBF) approximating 20 to 257, by weight of the sample. The sanilile is mixed thoroughly with D B F and diluted to aplxmimatcly i 0 to 80% on a total neight basis with reagent grade carbon tctracnhloride. The esact weight of the solvmt is not Hamilton micro syringe required. is used to inject the samlile into the chromatograph.
Quantitatioii i, acwml)li,*hed tiy rutting out carefully each peak, including the free alkyl i)hcnol, weighing, and wing the folloiving caI(d:ition. I h s e lines for each peak are (1ran.n from the start and rncl of the iieak. l ' h r 1)rwrnce of a high hckground in sonic case's is caiised by the ~ ~ r e s e n cof~ !nonclutahle comi)ountl,- and is grnrrally ignorctl. Figure 2 illustrates this prohlcm. Distillation cuts of a 9-mole a(ldurt d o not, with the cc*rlJtion ~ i t' h r [lot residue, give. this high base linr cfTc)ct.
Calculation. yGcomponent = peak w t . component X factor ~IJeak wt. IlliF
Wt.
x
-1
A\
RESULTS AND DISCUSSION
A typical chromatogram obtained with a 7 - ~ 1 .injection using the conditions of the method is s1ion.n in Figure 1 . VOL. 36, NO. 10, SEPTEMBER 1964
1915
Table I.
Average Molecular Weight of Trapped-Off Components
Average Compound mol. wt.O Std. 989; o-Sonyl phenol 235 Peak 1 1-mole hddurt 2.50 Peak 2 2-mole Adduct 299 Peak 3 3-mole Adduct 356 Peak 4 4-mole Adduct 410 Peak 5 5-mole Adduct 452 a Fisher vapor pressure osmometer ( 4 determinations) Ultraviolet method (1 determinationj.
To ascertain if the first peak represented the 1-mole adduct, a molecular distillation was run on the product. The first cut. which amounted to 1070, was discarded, while the second cut was taken and assayed for molecular weight by an ultraviolet procedure. This procedure depends upon the absorption of the aromatic nucleus a t
Average
Theoretical 220 264 308 352 396 440
niol. w t . b
238 252 297
350 406 447
F
2 i 6 mp. The molar absorptivity in methanol of the nonyl phenol nucleus of S P E O , products wab determined to be 1.54 X l o 3and was found to be constant, with products varying in the degree of ethosylation of the compounds studied. The molecular weight determined was 268. which compared favorably with 264 theoretical for the 1-mole adduct of nonyl phenol and ethylene oxide. 1he material representing this cut was reassayed, and the resulting peak was found to agree with the retention time of the first peak of the original chromatogram. The chromatogram of this material also showed about 10% of the material comprising the second peak, possibly accounting for the slightly high molecular weight. To determine if successive peaks as found in Polytergent B-150 (Figure 1) were succeeding adducts, a sample of the compound was chromatographed repetitively until 3 to 5 mg. quantities of the first five peaks, starting with the peak after DBF, were collected, and the molecular weight was determined for each trap. Table I shows that, based on molecular weight, the five peaks trapped correspond to the 1, 2, 3, 4,and 5 mole r 7
Table II. Relative Response Factors and Retention Time Data for Nonyl Phenol-Ethylene Oxide System
Compound CCI, Dibut.1 fumarate p-Konj 1 phenol 1-mole Adduct 2-mole Adduct 3-mole Adduct 4-mole Adduct 5-mole Adduct 6-mole Adduct i-mole Adduct 8-mole Adduct
Retention time (mm 1 (chart speed '/n-in / min.)
Table 111.
Run 1 2 ~
3 4
Relative response factors
0 2
3 4 4 8 6 3 7 8 9 0
10 4 11 6 12 6 13 7 14 5
1 00 1 13 1 28
1 41
1 69 1 i8
2 65
Replicate Analysis of Commercial 2-Mole Adduct
Components _ _
p-Sonyl phenol 2 8
Adduct 1 52 0
Adduct 2 34 6
2 4
49 7
3.2 2.5
50.0 50 . 2
34 1 34 5
34.2
Adduct 3 7 9 7 2 8.2 7.5
Adduct 4 0 8
Recovery 98 1
1 1
94 . 5 ~
1.2
96.8 95.5
i .O
Average 96.20
.
Calculated molecular weight 276 Actual molecular weight by U V method 282 Table IV.
Fraction 1
Gas Chromatographic Analysis of Distillation Cuts of Alkyl PhenolEthylene Oxide Product
Xonyl phenol
1 mole
8 7 8 5 0 8
4
0 8
2 mole 59 1 64 1 LO 3 21 6
3 mole 13 1 21 3 61 1
4 mole P P 18 9
66 7
19 4
5 mole P P
P P
6 mole P P P P
P P P
=
1916
present
ANALYTICAL CHEMISTRY
4x \
275°C
St
Retention Time
Figure 3. adduct
lgepal 210, 2-mole NPEO
adducts. Based on these data, each of the other peaks found in the chromatogram were assigned. I t is seen that up to the eight-mole adduct can be eluted from the column. Table I1 gives the retention data for each of the observed adduct peaks in the nonyl phenol-ethylene oxide. compounds. Determination of Response Factors. The response factors for the adducts were obtained by trapping-off each component into a tared capillary tube, weighing the sample, dissolving in CCl,, reweighing, and then chromatographing the standard solution. For this work, 6 to 7 mg. of each component up to and including the fivemole adduct were trapped. Any impurity in the prepared standards could be detected during the rerun and was corrected for by internal normalization. .A plot of 'response us. weight sample was linear in the ranges of 0 to 70 wt. 76 for all adducts. Relative response factors are shown in Table I1 for the nonyl phenol-ethylene oxide adducts. The reason for the relatively high value for the 5-mole adduct is not understood. Response factors were not calculated for adducts containing more than five moles of ethylene oxide. Reliability Studies. Reproducability of the method was ascertained from replicate anal) two-mole ethylene oxide adduct of nonyl phenol. The analysis indicating recovery of the sample and a comparison of the calculated molecular weight with that of the actual molecular weight are shown in Table 111.
~
Table V.
Analysis of Various Nonyl Phenol-Ethylene Oxide Condensates
Weight Konyl phenol 2 8 0 8 Trace Trace 0 5
Compound 3 mole S P E O 4 5 mole UPEO 6 0 mole TPEO 9 0 mole ?;€’EO I O 5 mole S P E O P = present a Ultraviolet procedure Table VI.
1 mole
52 0 0 8 Trace Trace 0 8
2 mole 34 6 10 2 2 1 0 2
1 2
$c
Composition
3 mole 7 9 22 3 6 9
oa
1 4
4 mole 0 8 19 8 12 7 1 4
0 7
5 mole P 15 9 18 5 4 5 11
6 mole
7 mole
8 mole
P P P P
P P P P
P P P P
Detnd mol w t 2b2 363 501 669 729
Comparison of Experimental Data with Theoretical Data Based on Poisson Distribution Function
Detnd. mol.
Compound 1vt.a Igepal 210 282 363 Polytergent B-150 501 Poll-tergent B-200 669 Polytergent B-300 729 Polytergent B-350 Vltraviolet procedure.
KPEO1 Found Theory 52.0 55.99 0.8 3.10 Trace 0.37 ruckerei, 1961. RECEIVED for review March 11, 1964. Accepted June 17, 1964.
Radiometric Determination of Adsorption Isotherms from Solution on Organic Substrate JEROME HABERMAN (and THOMAS C. CASTORINA Explosives laboratory, Feltman Research laboratories, Picatinny Arsenal, Dover, N . J .
b
The adsorption by 6-octahydro1,3,5,7-tetranitro-s-tettazine (HMX) of the carbon-1 4-labeled quaternary salt, stearyltrimethyl lommonium bromide (STAB), from solution was studied. A solvent system consisting of 90% water and 10% ethanol gave acceptable isotherms on 10-micron HMX. The data are shown to b e quantitative and reproducible with a standard deviation of 0.01 mg. of STAB per gram of HMX. The knee portion of
the curve is below the critical micelle concentration of the STAB solution, indicating that the plateau represents true saturated adsorption.
P
on the adsorption of surfactants (adsorbates) from solution onto inorganic adsorbents (substrates) using radiotracer techniques have been reported ( 9 ) . The surface areas of these substrates were about REVIOUS STUDIES
5 to 50 sq. meters per gram. I n addition, the interactions of these adsorbents with the surfictants were sufficiently large to give q)ecific adsorbawes that were readily measured. However, no work has been reported on the al)plication of radiotracers for the determination of adsorption from solution by an organic substrate. Organic solids have relatively inacti1.e surface5 because of their small surface areas (nonporous) and low degree of VOL. 36. NO. IO, SEPTEMBER 1964
1917
