Infra-red spectral analysis of Soviet opium: simultaneous determination of narcotine, thebaine and papaverine

Sections

Discussion

Details

Author: V. M. Merlis , E. I. Kryukova , A. A. Chemerisskaya , E. M. Peresleni , A. A. Ivanov
Pages: 5 to 8
Creation Date: 1968/01/01

Infra-red spectral analysis of Soviet opium: simultaneous determination of narcotine, thebaine and papaverine *

V. M. Merlis 1
E. I. Kryukova 2
A. A. Chemerisskaya 3
E. M. Peresleni 4
A. A. Ivanov 5
Sergo Ordzhonikidze All-Union Chemical-Pharmaceutical Research Institute (VNIKhFI), Moscow, 1966

In determining the percentage content of alkaloids in opium by chemical methods, the separation of the individual alkaloids one from another is a time-consuming and laborious process. For this reason great interest undoubtedly attaches to methods whereby the contents of several alkaloids can be determined simultaneously without separating and isolating them in a relatively pure form.

In recent years, the literature has referred to the possibility of simultaneous quantitative determination of opium alkaloids and their derivatives by infra-red spectroscopy.

Thus the method was used in 1955 to make a quantitative determination of the papaverine and oxycodone content in a mixture of the two [ 1] . Infra-red spectroscopy was also used in later studies [ 2] , [ 3] to identify and determine the purity of Reinecke salts of narcotine and papaverine isolated in the analysis of mixtures of the pure substances and opium, and also to make a quantitative determination of narcotine in the presence of papaverine in a mixture of the pure substances. In 1959 C. G. Farmilo et al. [ 4] gave a detailed description of a quantitative method employing infra-red spectra which had been developed for the simultaneous determination of the content of narcotine (at 1,767 cm-1), thebaine (at 1,602 cm-1) and papaverine (at 1,160 cm-1) in opium; the view was to use the method to establish the geographical origin of the opium. A method for the simultaneous determination of morphine, codeine and porphyroxine in opium was proposed for the same purpose in 1962 [ 5] ; the first two of these alkaloids were determined by infra-red spectroscopy, and porphyroxine by the measurement of absorption in the visible range of the spectrum.

The original of this article is in Russian.

1

Director of the Opium Group; Senior Scientific Officer.

2

Senior Chemist.

3

Superintendent of the Analytical Chemical Laboratory.

4

Senior Engineer, Physical Chemical Laboratory.

5

Junior Chemist, Physical Chemical Laboratory.

At the invitation of Professor C. G. Farmilo (Canada) we acquainted ourselves with the methods described in his papers [ 4] , [ 5] and applied them to the analysis of Soviet opium. The present paper describes the results obtained in the simultaneous determination of narcotine, thebaine and papaverine in Soviet opium.

A Perkin Elmer Model 221 recording spectrophotometer was used in studies by Farmilo and co-workers [ 4] , [ 5] .

In the present study a UR-10 infra-red recording spectrophotometer was used to record the infra-red spectra of carbon tetrachloride solutions of all the substances investigated. The solution concentrations and layer thicknesses employed were those indicated in [ 4] .

The spectra of solutions of the pure substances and of artificial mixtures thereof were found to be very similar to the corresponding infra-red spectra given in [ 4] , with some slight differences, namely that the peaks characteristic for thebaine and papaverine had shifted somewhat. The thebaine peak was noted at 1,609-1,610 cm-1 instead of 1,602 cm-1, and the papaverine peak at 1,163 cm-1 instead of 1,160 cm-1. The absorption coefficients we found for the pure bases are given in table 1. These coefficients are similar to, but not identical with, those given in the corresponding table II of paper (4). Additional purification of the bases and repeated spectroscopic examination had no perceptible effect on the differences noted.

Thereafter we proceeded to analyze samples of Soviet opium.

The method used in preparing opium extracts for infra-red spectroscopy is based on the principle of separating opium alkaloids into two main groups in accordance with the unified method set out in [ 6] . One group comprises those alkaloids that are extracted by chloroform from an acetic acid solution (narcotine, thebaine, papaverine and some of the minor phenolic alkaloids); the other group - those left behind in the aqueous acetic acid solution - comprises morphine, codeine, cryptopine, narceine and the remaining phenolic alkaloids.

TABLE 1

Absorption coefficients of pure bases at their characteristic frequencies

 

Absorption at specified frequencies, in cm-1

Alkaloid

Concentration mg/25 m CC1 4

A1, 767

A1, 850

A1, 767- A1, 850

A1,602

A1,645

AI, 602- A1, 645

A1, 160

A1, 172

A1, 160- A1, 172

Narcotine
100 0.796 0.020 0.776 0.071 0.036 0.035 0.055 0.054 0.001
Thebaine
70 0.004 0.001 0.003 0.267 0.009 0.258 0.108 0.003 0.025
Papaverine
50 0.005 0.004 0.001 0.027 0.004 0.023 0.258 0.041 0.217

To separate opium alkaloids into the two above-mentioned groups, 4.5 g of powdered, sieved opium are triturated with 20 ml of glacial acetic acid, after which 25 ml of water are added and trituration is repeated. The resultant homogeneous mixture is filtered, and an aliquot (10 ml), which corresponds to 1 g of opium, is taken for the determination. Five separatory funnels, each of approximately 125 ml capacity, are used in the extraction of the alkaloids by chloroform. The stipulated 10 ml of filtrate are placed in the first funnel with 10 ml of chloroform; the remaining funnels are filled with the solutions specified in [ 4] for purification of the chloroform extract which, after shaking and standing, is passed successively from one funnel to another. Samples are taken in the process of extraction to verify the completeness of extraction of thebaine (syrupy phosphoric acid), narcotine (sodium persulphate in concentrated sulphuric acid) and papaverine (Froehde's fuming reagent).

Thereafter the analysis procedure is much simpler than the method described in [ 6] ; instead of the lengthy and tedious separation of narcotine, thebaine, papaverine and phenolic bases, the filtered chloroform solution is evaporated and the residue is dissolved in specially purified and distilled carbon tetrachloride and filtered into a 25 ml measuring flask. The phenolic alkaloids, insoluble in carbon tetrachloride, remain in the filter bed. The clear solution is made up in volume with the same solvent and its infra-red spectrum is taken.

We analysed three samples of Soviet opium by the proposed method: Nos. 10 and 11 were in dry powder form, while No. 8 was raw (semi-liquid) opium with a moisture content of more than 35 per cent. The latter sample was deliberately selected in order to establish that it was also possible to determine alkaloids by infra-red spectroscopy in moist opium, since Soviet opium has, in most instances, a very high moisture content. We therefore determined the alkaloid content of sample No. 8 both in the raw state and in a specimen air-dried under a fume hood. To obtain the latter, a quantity of carefully mixed opium was applied to a slide and, as it dried, was augmented with more of the same mixture. The dried layer was removed from the slide and carefully ground and stirred.

The infra-red spectra of solutions of opium extracts under these conditions exhibited somewhat sharper deviations from the characteristic frequencies of individual alkaloids than do the infra-red spectra of the pure alkaloids. There are slight differences of peak configuration for the same alkaloid in the infra-red spectra of different samples of opium. The papaverine peak at 1,160 cm-1 was particularly indistinct, and this made it very difficult to select the characteristic absorption band of papaverine.

Because the UR-10 instrument records the spectrum on a percentage transmission scale and not on an optical density scale as was the case in (4), we used the following conversion formula to calculate the concentrations:

D=log(1 / T)

where D = optical density

T = transmission coefficient

1 / T = reciprocal of the transmission coefficient.

On examining the results obtained from the analysis of opium samples which appear in table 2, it will be seen that those obtained in the determination of papaverine are fairly consistent but slightly lower than the figures obtained by chemical analysis, and that the difference is greater for sample No. 11 than for sample No. 10.

With sample No. 10, the results of thebaine determination are also consistent, but somewhat higher than the figure obtained by chemical analysis. The data obtained with sample No. ll average out at a figure close to that obtained by chemical analysis but differ widely from one another.

In narcotine determination, the results obtained with sample No. 10 are adequately consistent, but there are discrepancies in the data obtained with sample No. 11. Moreover the average of the figures obtained by infra-red spectroscopy is somewhat higher than the figures obtained by chemical analysis of the same samples.

TABLE 2

Comparison of results obtained in the analysis of samples of Soviet opium by infra-red spectroscopy and by chemical methods

 

Percentage content of alkaloids

 

Narcotine

Thebaine

Papaverine

Origin and number of opium sample

Infra-red

Chemical

Infra-red

Chemical

Infra-red

Chemical

  9.09   3.63   3.54  
10 8.67   3.31   3.27  
Kirghizia
9.07 8.28 3.67 3.09 3.47 3.73
(powder)
9.07   3.73   3.34  
  9.18       3.26  
11 Kirghizia (powder)
7.10   2.88   1.84  
  7.78 6.35 3.58 3.25 1.83 2.85
  7.74   3.61   2.03  
  8.01       2.12  
8            
Kazakhstan
7.71 6.62 1.88 1.21 2.32 2.22
(semi-liquid)
          2.49
Converted to dry substance
12.1 11.32 2.96 2.08 3.65 4.26
Air-dried
10.71
-
3.41
-
4.10
-
  10.71   3.32   4.00  

If we examine the corresponding table in paper (4) (table IV, p. 240), we again find that the results obtained by infra-red spectroscopy are most consistent in the case of papaverine and somewhat less so in that of thebaine. The results obtained for narcotine are not consistent for all samples, and in three cases out of five the results arrived at by infra-red spectroscopy are higher than those obtained by chemical analysis.

From the results we obtained with semi-liquid raw opium having a moisture content of more than 35 per cent it will be seen that, despite some discrepancies, this substance is also capable of analysis by infra-red spectroscopy.

Discussion

In determining the geographical origin of opium, figures which express the content of one alkaloid in proportion to the content of another alkaloid - proposed earlier in [ 7] and repeatedly used by us in describing Soviet opium [ 8] , [ 9] - are of more use than absolute figures expressing the percentage content of alkaloids. Hence particulary high accuracy is not aimed at in the determinations.

If, in addition to the data on the content of the above-mentioned alkaloids, data on morphine and codeine are also obtained by some method, the codeine/morphine and narcotine/morphine ratios can be calculated.

From the data obtained, the opium sample analysed can be assigned to one or other of the groupings: lndo-Iranian, Turco-Yugoslav or Sino-Korean [ 7] .

From our observations it would also be useful, for the purpose of identifying opium, to work out a method for determining the proportion of papaverine to other individual alkaloids, since the papaverine content varies widely in opium from different sources.

In the light of the foregoing it must be acknowledged that the application of infra-red spectroscopy to the simultaneous determination of narcotine, thebaine and papaverine in opium may prove very useful, especially in large-scale analyses, because it is undoubtedly much less time-consuming than chemical methods of analysis.

References

001

Salvesen, Domange and Guy, Ann. pharm. franc., 13, 354 (1955).

002

Lee Kum-Tatt, Farmilo, C. G., J. Pharm. Pharmacol., 10, 427 (1958).

003

Lee Kum-Tatt, Rockerbie, Levi, J. Pharm. Pharmacol., 10, 621 (1958).

004

Bakre, V. J., Karaata, Z., Bartlet, J. C., Farmilo, C. G., J. Pharm. Pharmacol., II, 234 (1959).

005

Genest, K., Farmilo, C. G., Analytical Chemistry, 34, 1464 (1962).

006

Fulton, United Nations document, ST/SOA/SER.K/34 (1954).

007

United Nations Secretariat, ST/SOA/SER.K/38 (1955).

008

Ruzhentseva, A. K., Merlis, V. M., et al., ST/SOA/SER.K/89 (1959).

009

Ruzhentseva, A. K., Merlis, V. M., et al., ST/SOA/SER.K/124 (1962).

MISCELLANY

TERATOGENIC PROPERTY OF LSD

The finding of chromosomal abnormalities in cultured cells grown in the presence of LSD was followed by several new scientific communications on the teratogenic (foetal malformation) properties of this substance. Recently it was proved by G.F. Alexander and his co-workers that in rats a single injection of LSD on the fourth day of pregnancy at a dose of 5 mg/body weight - corresponding to the human hallucinogenic dose (1.7 to 6.7 mg/kg) - may cause abortions, malformation and significantly retarded development of the off-spring. (Mental Health Digest, U.S. Department of Health, Education and Welfare, Dec. 1967, p. 15.)

Zellweger and co-workers from the University Department of Pediatrics, Iowa City, United States, are continuing their studies on the effect of lysergide on the chromosomes. They write that while the significance and effects of chromosome breaks are unkknown, their works suggests presumptive evidence that LSD, if taken by a woman during the organogenetic period of her pregnancy, may hava a teratogenic effect on the foetus. ( Lancet, 1967, II: 7529, p. 1306.)

CANNABIS IN EARLY PREGNANCY

Referring to the report by zellweger et al of the first case of human teratogenicity with possible causal relationship to LSD ( Lancet, Nov. 18, p. 1066), Persaud and Ellington from the Department of Anatomy, university of the West Indies, Kingston, Jamaica, write that the resin of cannabis, like LSD, produces abnormal mental phenomena in both the cognitive and perceptual spheres. They tested the effects of the resin on the mouse embryo, in their programme of screening drugs of West Indian origin for embryopathic activity. The foetuses of pregnant mice treated on day 6 of gestation with a single intraperitoneal dose (16 mg per kg) of the resin showed a high incidence of over-all stunting. No apparent malformations were observed The size of the litter was not significantly reduced. There were complete foetal resorptions in animals given 16 mg per kg of the resin intraperitoneally daily for days 1 to 6 of gestation. ( Lancet, 1967, II: 7529, p. 1306.)