the R value of the carotene in the zone of the eluting substance, which may vary from t h a t of the eluting substance to 1. It may be established in separate experiments in which solvent plus eluting substance are added t o the column before addition of the solution of carotene plus eluting substance. A t first sight, Figure 1 appears to indicate a marked distinction between eluting agents-those t h a t migrate faster than the carotene-and displacing agents-those t h a t displace the carotene and follow the displaced zone through the column. B u t the results n ith certain ethers, nitro compounds, and ketoncs show that the transition from rlution to displacement may vary n i t h concentration as well as n i t h the nature of the eluting substance. For the rlution effect, R for carotene in the presence of the eluting agent must be less than R of the eluting agent. For the displacement effect, R for carotene in the presence of the displacement a g n t must be greater than R of the displacing agent. With respect to concrntration and structure, there is a gradual transition from eluting substances to displacing substances, and no special selective elution properties may be attributed to one in preference to the other.
From these observations, one may envision a n elution mechanism in which the eluting agent and the solvent compete with carotene for the active surface of the magnesia and in which sorbed eluting agent and the dissolved eluting agent have attractive forces for carotene. Only with very strongly sorbed substances such as the alcohols, is virtually all the carotene displaced from the magnesia. The differences in the shape of the curves for different eluents indicate that the detailed elution mechanism varies from eluent t o eluent and, with many substances, from one concentration to another. LITERATURE CITED
(1) Bickoff, E. M., ANAL.CHEM.20, 51
11948). (2) Brockman, H., Volpers, F., Chem. Bey. 82,95 (1949). (3) Cassidy, H. G., “Adsorption and Chromatography,” Interscience, New York, 1951. (4)Cassidy, H. G,.: “Fundamentals of Chromatography, Interscience, S e w York, 1957. (5) Franklin, E. C., “The Nitrogen System of Compounds,” Reinhold, New York, 1935. (6) Hartshorn, L., Milligan, A. G., “International Critical Tables.” Vol. 6,81, 1929. (7) Jacques, J., Mathieu, J. P., Bull. SOC. chzm. France 1946, 94. I - -
- - I
(8) Lederer, E., Lederer, M., “Chromatography: a Review of Principles and Applications,” Elsevier, Kew York, 1953. (9) Margott, A. A., Buckley, F., “Table of Dielectric Constants and Electric Dipole Moments,” National Bureau of Standards Circular 537, June 25, 1953. (IO) Margott, A. A., Smith, E. R., “Table of Dielectric Constants of Pure Liquids,” National Bureau of Standards Circular 514, August 10, 1951. (11) Steiger, M., Reichstein, T., Helv. Chim. Acta 21,546 (1938). (12) Strain, H. H., ANAL. CHEM. 33, 1733 (1961). (13) Strain, H. H., “Chloroplast Pigments and Chromatographic Analysis,” 32nd Annual Priestley Lectures, The Pennsylvania State University, University Park, Pa., 1958. (14) Strain, H. H., “Chromatographic Adsorption Analysis,” Interscience, New Yprk, 1942. (15) Strain, H. H., IND.ENG. CHEM., AKAL.ED. 18, 605 (1946). (16) Strain, H. H., J . Am. Chem. SOC. 70,588 (1948). (17) Trappe, W., Biochem. 2. 305, 150 (1940); 306, 316 (1940); 307, 97 (1941 ~~- ~’i._ , (18) Williams, J. W., J . Am. Chem. SOC.
50,2350 (1928). (19) Williams, R. J. P., Hagdahl, L., Tiselius, A., Arkiv. Kemi 7 , 1 (1!354).
RECEIVED for review October 12, 1961. Accepted January 8, 1962. Based on work performed under the auspices of the U. S. rltomic Energy Commission.
Identification of Fluorenones in Wilmington Petroleum by Gas-Liquid Chromatography and Spectrometry D. R. LATHAM, C. R. FERRIN, and J. S. BALL Laramie Petroleum Research Center, Bureau of Mines,
b Alkyl-substituted fluorenones have been identified from Wilmington, Calif., petroleum b y API Research Project 52 and are the first aromatic ketones found in petroleum. A fraction boiling from 320” to 330” C. was reacted with sodium amide in liquid ammonia, The regenerated precipitate was separated into fractions b y gas-liquid chromatography. A low-voltage mass spectrum of one of these fractions showed the molecular weights of C1to Ca-substituted fluorenones and indicated one of them had the molecular formula of C16H120. An infrared spectrum of the fraction showed the presence of a carbonyl group. An ultraviolet spectrum of the fraction was compared with the standard spectra of fluorenone and 4-methylfiuorenone, to establish definitely the class of compound.
A
U. S. Department of the
LKYL-SUBSTITUTED
Interior, Laramie, Wyo.
FLUORENONES
have been identified in a Wilmington, Calif., crude oil b y a combination of mass, infrared, and ultraviolet spectrometry on a sample obtained by distillation, chemical extraction, and gaaliquid chromatography. Fluorenones are the first aromatic ketones to be identified from petroleum. This identification was made by American Petroleum Institute Research Project 52b (Nitrogen Compounds in Petroleum) when a reagent used to extract nitrogen compounds also extracted fluorenones. Oxygen compounds in petroleum have received less study than sulfur and nitrogen compounds because they have caused fewer problems during refining operations. A review (1) has shown fatty acids, naphthenic acids, and phenol to be present in petroleum. In addition, Barton, Carruthers, and
Overton (2) identified a triterpenoid lactone from petroleum and Lochte and Littmann (9) reported the identification of several aliphatic ketones from a gas well condensate. EXPERIMENTAL
A 21-barrel sample of Wilmington, Calif., crude oil was obtained from the field for the use of various API fundamental research projects. This sample was protected from oxidation by blanketing with specially purified nitrogen gas containing less than 2 p.p.m. of oxygen. All subsequent handling of t h e fractions from this oil has been under this same protection. A portion of this oil was deasphaltened with pentane (8) and vacuum distilled (7’) t o obtain a fraction boiling from 320’ to 330” C. at a pressure of 760 mm. of Hg. A low-voltage mass spectrum of this fraction is shown in panel I of Figure 1. VOL. 34, NO. 3, MARCH 1962
31 1
collected on a time basis. Low-voltage mass spectra showed that one of these fractions contained compounds with molecular weights of 194, 208, and 222. An isotope-corrected low-voltage mass spectrum of this fraction is shown in panel I11 of Figure 1. Comparisons of the ultraviolet spectra (5) of anthraquinone, anthrone, fluorenone, 4methylfluorenone, and the GLC fraction are shown in Figure 2. The infrared spectra of fluorenone and the GLC fraction are shown in Figure 3. Both of these infrared spectra were obtained using the potassium bromide pressed-plate method to prepare the samples.
ml e 160
180
220
200
260
240
280 I
PANEL
I
320'-330'
I
Fraction
4 Figure 1 . Mass spectral data
1
PANEL II
P
Sodium Amide E ~ l r o c l Low VO If 0 (e YO I S SQaC I1U n
-
60
PANEL
-
40 20
-
IU
GLC Fraction L o w - V o l l a q e YacS Speclrum
i
DISCUSSION
The 320' to 330' C. fraction is very complex as shown in the low-voltage mass spectrum in panel 1 of Figure 1. Compounds of almost every evennumbered molecular weight from 192 to 286 and a few compounds of odd molecular weight from 167 to 227 are present. Some of the components of this plex fraction were separated by reaction with sodium amide in liquid ammonia. Alkali metals are reported (6) to react with aromatic hydrocarbons containing acidic ring hydrogens to form the metal
' ,
160
Id0
200
220
240
260
280
mle
The 320' to 330' C. fraction was diluted with pentane and reacted with sodium amide in liquid ammonia ( 7 ) . T h e precipitate from this reaction was hydrolized with distilled water. The resulting oil-water mixture vias extracted consecutively with pentane and benzene. The two extracts were combined and the solvents evaporated. The ultraviolet spectrum of this sodium amide extract showed i t to be aromatic in character, and the infrared spectrum indicated the presence of compounds containing a carbonyl group. Further interpretation of these spectra could not be made because of the complexity of the extract. A loiv-voltage mass spectrum of the extract is shon n in panel I1 of Figure 1. 4 portion of the sodium amid(, extract mas treated with p-nitrophenylhydrazine to remove t h e carbonyl compounds. Equal weights (0.3 gram) of the extract and p-nitrophenylhydraBine were dissolved in absolute ethyl alcohol, 1 drop of acetic acid added, and the solution boiled for 10 minutes. The solution was cooled and filtered to remove the precipitate. After removal of the ethyl alcohol solvent from the filtrate, a low-voltage mass spectrum of the unreacted oil showed that the concentration of the compounds suspected of being aromatic ketone9 was reduced by 30%. Experiments were made to show that fluorenone would be extracted by sodium amide and that fluorene would not be oxidized to fluorenone by a similar treatment. Fluorenone in xylene solution was added t o sodium amide in liquid ammonia and the precipitate from the reaction of the sodium amide and fluorenone was regenerated to fluorenone. When reacted with sodium amide, fluorene was found to form a precipitate. Ultraviolet and infrared spectra of the regenerated material from this reaction showed it to be fluorene with no fluorenone present. The sodium amide extract was separated into fractions using a gas chro-
3 12
ANALYTICAL CHEMISTRY
matographic unit containing a '/r-inch by 10-foot aluminum column packed silicone n,ith Dow corning high grease supported on Chromosorb and maintained at 250' C. The detector lyas turned off to minimize decomposition from the hot wire and fractions
Y
-
u
s 30
L
b Figure 2. Ultraviolet spectra of anthraquinone, anthrone, fluorenone, 4-methylfluorenone, and GLC fraction
I 2300
2MO
2700
29W
3tW
WPVE LENGTH, AYGITROYS
3300
3500
salt4 of the hydrocarbons. Aromatic ketones are also reported (4) to react with alkali metals to form free radical compounds called “metal ketyls,” which are represented by the general formula R=C-Oi\I. The reaction a i t h sodium amide in liquid ammonia is assumed to give similar products which can be hydrolyzed to the original compounds. As shown in panel I1 of Figure 1, the components of the sodium amide extract appear to belong to only three homologous serit.s of compounds. These series and their approximate concentration in the extract are:
Mass Sumbers Series I Series I1 Series I11
167, 181, 195, 209 192, 206, 220 194, 208, 222, 236
Per Cent of Total Ionization 22 12
I0
a 40
60 80 I0
-
4I
5!
6I
I
81
9!
I IO
1 I1
2I
13 I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
1
I
1 2
,3
14 I
d16
15
(r 0
Y
80
20
! 2
3
1
I 4
5
Figure 3.
6
4
GLC GLC FF RR AA CC TT II O O NN
IO
66
The compounds of series 1 are carbazole and its C1-to C3-substituted homologs ( 7 ) . The series I1 compounds were not investigated, but their molecular weights correspond to C1- to Crsubstituted anthracenes or phenanthrenes. Types of compounds that have the correct molecular weights for series 111 and have a carbonyl group in the molrcule include fluoronones. anthrones, anthraquinones, and phenanthrones. The ultraviolet spectrum of the fraction from the GLC separation of the sodium amide extract was compared with standard spectra (5) of anthrone, anthraquinone, fluorenone, and 4methylfluorenone as shown in Figure 2. The ultraviolet spectra of the fluorenones are the only ones that match the spectrum of the GLC fraction. Khile there is slight shifting of the peak maxima on the spectrum of the GLC fraction as compared to the maxima for fluorenone and 4-methylfluorenone, this is due to the substituent groups of the fluorenones in the GLC fraction. The general shape and characteristics of the three curves are the same. Although a standard ultraviolet spectrum of phenanthrone was not available for comparison, this compound was not considered a likely component because it is estremely unstable (11, IZ), changing color from pale yellow to pink to dark red in less than 30 minutes in ethyl alcohol solution or when exposed to air. When the GLC fraction was exposed to air, no change in its color occurred. The isotope-corrected low-voltage mass spectrum of the GLC fraction (panel 111, Figure 1) shows compounds with molecular weights of 194, 208, and 222. These molecular weights correspond to CI-, Cz-, and Crsubstituted fluorenones. The parent compound, fluorenone, with a molecular weight of
1
FLUORENONE
A
r ZC 2
7
8
9
1 0 1 WAVELENGTH IN MICRONS
1
1
I 4
1
5
1
6
Infrared spectra of fluorenone and GLC fraction
180, was not found in this fraction, nor was i t present in the sodium amide extract. Evidence of one oxygen atom in the molecule Kith the molecular Iveight 208 was found by using a method developed by Lumpkin and Nicholson ( I O ) . This method permits calculation of the isotopic contribution of a parent peak to the next higher peak by using the number of carbon, hydrogen, and oxygen atoms present in the molecule. If the parent 208 peak has a molecular formula of CI6Hi6, the ratio of peak heights for the 209 to 208 peaks would be 0.175. For a molecular formula of C16Hi20, the ratio would be 0.164, and, for a molecular formula of C14H802, the ratio would be 0.153. The observed value for the 208 peak in the GLC fraction was 0.165, indicating a n average molecular formula of ClsH120. This corresponds to a Cz-substituted fluorenone. A comparison of the infrared spectrum of the GLC fraction with t h a t of fluorenone is shown in Figure 3. The infrared spectra of substituted fluorenones were not available for comparative purposes. Agreement between the t n o spectra is seen at wavelengths of 5.90, 6.25, 6.90, 10.95, and 13.65 microns. The peak a t 5.90 microns is due to the carbonyl group. Some information on the substituent groups and their positions on the ring can be obtained from the infrared spectrum. Peaks a t 3.45 and 3.55 microns show the presence of CH2 and CH, groups. The peak at 13.65 microns s h o w the presence of four adjacent hydrogen atoms on a n aromatic ring (S), which indicates that one ring of some of the molecules present is free of substituent groups. T h e absence of
peaks in the 11.6- to 12.5-micron region, the definitive area for tn-o adjacent ring hydrogen atoms, and the 11.1- to 11.5micron region, the definitive area for one isolated ring hydrogen atom. indicates the substituents are on the 1-, 4-, 5-, or 8-positions. T h e peaks a t 12.8 and 15.0 microns indicate three adjacent ring hydrogen atoms and show 1- or 4-position substitution on either ring. LITERATURE CITED
(1) Ball, J. S., Haines, W. E., Helm,
R. V., World Petrol. Congr. Proc. 6th Congr., sec. V , 175-89, New York, 1959. (2) Barton, D. H. R., Carruthers, W., Overton, K. H., J . Chem. Sac. 1956, 7QQ I V”.
(3) Bellamy, L. J., “The,:nfrared EpecLra of Complex Molecules, 2nd ed., p. ( 7 , Riley, New York, 1958. (4)Bent, H. E., Harrison, A. J., J . Am. Chena. Soc. 6 6 , 969-73 (1944). (5) Friedel, R. A,, Orchin, M., “Ultraviolet Spectra of Aromatic Compounds,” Wiley, New York, 1951. (6) Greenhow, E. JT., White, E. N., XlcNeil, D., J . Chem. Sac. 1951, 544. (7) Helm, R. V., Latham, D. R., Ferrin, C. R., Ball, J. S., AKAL.Cmar. 32, 1765 11960). (81 Helm, R. V., Latham, D. R., Ferrin, C. R., Ball, J. S.,J. Chem. Eng. Data 2 , 9 5 (1957). (9) Lochte, H. L., Littmann, E.,,R., “The Petroleum Acids and Bases, p. 233, Chemistrv Publishing- Co.., New York. 1955. (10) Lumpkin, H. E., Nicholson, D. E., ANAL.CHEM.32, 74 (1960). (11) Moriconi, E. J., Wallenberger, F. T., Kuhn, L. P., O’Connor, JT, F., J. Org. Chem. 22, 1651 (1957). (12) R a m , F. R.. Findlev. A.. J. Chem. ‘ SOC. 1897, 1121.’
RECEIVED for review September 29, 1961. Accepted January 2, 1962. Division of Petroleum Chemistry, 140th Meeting, ACS, Chicago, Ill., September 1961. VOL. 34, NO. 3, MARCH 1962
313
