Committee of Experts on the United Nations Programme of Opium Research


A. Question of opium types
A. Initial Procedure
B. Preliminary Analytic Steps
C. Methods
D. Record of results of analysis
E. Interpretation of Data:Alternative Systems for classifying Opium Types


Pages: 37 to 44
Creation Date: 1958/01/01

Committee of Experts on the United Nations Programme of Opium Research [1]


A. Question of opium types

It was observed that opium types had not yet been established. The Committee decided that this was a basic question on which it would be necessary to reach a definite conclusion. For this purpose it was felt to be necessary to define the term "opium type "; to delineate the various types; to indicate the geographical areas where each was produced, and to make the necessary arrangements for this work to be carried out. The following definition was adopted:

"An opium type is one whose physical and chemical characteristics lie within defined limits."

As regards this draft definition, the Committee noted that the variations in characteristics from year to year may increase or decrease the number of types within a particular country.

" The story of ‘porphyroxine-meconidine ’ " (Vol. IV, No. 1);

" Progress in determining the origin of illicit opium" (Vol. V, No. 1).

The character of each opium type should be elucidated by measurement of its chemical and physical properties, and the limits should be defined as closely as possible, taking into account all the available information.

Variations in moisture should not constitute a difference in type, and the various constituents should be calculated on anhydrous opium or on opium having a constant moisture content.

The need to establish the various opium types by defining the ranges for each of their characteristics was recognized. This would constitute an important step forward in the scheme for establishing opium origin.

It was noted that more authenticated samples were available from India than from any other opium producing country, yet only a tentative classification could be made for Indian types. As regards the other producing countries - from which fewer samples were available - difficulties were naturally much greater. The scientists stated that their international collaboration on opium could not progress to the final stage of delineating opium types until all the countries had supplied authenticated samples.


The Committee considered as authenticated samples only those that had been "furnished and authenticated by the government of the country of origin as opium produced in that country ".

A review was made of the countries and territories throughout the world where there was a question of licit or illicit production to determine how fully they were represented among the samples used for the research programme.[3]

  1. Countries with Licit Production


In 1956, licit production amounted to 12.2 tons. Three authenticated samples of Afghan opium were available.


Bulgarian licit production varied between 6.7 and 1.1 tons during the period 1952-1956. No authenticated samples of Bulgarian opium were available.


Licit production, which was discontinued in 1953, would perhaps recommence in 1958. An authenticated sample of Greek opium was available.


India was one of the principal producers of licit opium. During the past five years, production varied between 347.7 tons in 1956 and 629 tons in 1953. One hundred and sixty-seven authenticated samples of Indian opium were available.


Beginning in 1956, licit opium production had been prohibited, and further intensive measures were taken to suppress illicit cultivation. Thirty-two authenticated samples of Iranian opium were available.


Opium production had been begun in 1954, and in 1955 consisted of 2.3 tons, and in 1956 of 2.0 tons. Fourteen authenticated samples of Japanese opium were available.


Licit production in recent years had varied between 4.6 tons in 1954 and 165 kg in 1952. Six authenticated samples of Pakistani opium had been received.


Turkey was one of the principal producers of licit opium. Turkish production had varied recently between 466 tons in 1952 and 70 tons in 1954; in 1956, 277 tons were produced. Thirty-four authenticated samples of Turkish opium comprising 110 separate lumps had been made available, and additional samples were expected in the near future.

Union of Soviet Socialist Republics

The Union of Soviet Socialist Republics was the third largest producer of licit opium; production took place in the Kazakh and Kirghiz Soviet Socialist Republics, and during the past five years had varied between 92 tons in 1953 and 108 tons in 1955. No authenticated samples of Soviet opium were available.


Licit production of opium in Yugoslavia had varied between 12 tons (1952, 1954) and 28 tons (1956). An authenticated sample of Yugoslav opium consisting of a number of lumps which might or might not come from different producing areas had been received.

  1. Countries with Illicit Production, having furnished Authenticated Samples


There was illicit production in certain regions. Only one authenticated sample was available to the United Nations Opium Distribution Centre.

Korea, Republic of

The Government had reported some illicit production in 1956. One authenticated sample of Korean opium was available.


The Government had reported some illicit production. Five authenticated samples of Laotian opium had been made available in 1950.


There was illicit production of opium in the western mountain districts; one authenticated sample of Mexican opium was available.


One authenticated sample of Nepalese opium had been received, but no information was available on opium production, licit or illicit, in that country.


The Government reported in 1956 that illicit opium production in Viet-Nam had been completely suppressed. One authenticated sample of Viet-Namese opium consisting of a number of small lumps which came from the same or different localities was available.

  1. Countries which have not furnished Authenticated Samples


Production was illicit, and no authenticated samples of Ecuadorian opium were available.


The Government stated in 1956 that cultivation of opium poppy was not known in Lebanon. If there was production of illicit opium at other times, no authenticated samples were available.


There was some illicit production. No authenticated sample of Thai opium had been received.


The Government have reported some illicit cultivation of the opium poppy, but authenticated samples of Tunisian opium, if any has been produced, have not been received.

United Arab Republic

Production was illicit, and no authenticated samples of opium were available.

No recent information was available for the following countries: China and Peru.

In some instances, supporting information serving to identify the exact geographical origin of many of the authenticated samples was lacking, and also the dates and circumstances of harvesting and storage were unavailable.

The Committee accordingly decided to recommend to the Commission on Narcotic Drugs that the governments of the above-mentioned countries should be urged to furnish many more authenticated samples, and that each sample, in so far as possible, should be accompanied by the following detailed information:

  1. Year of production;

  2. Precise locality of production;

  3. Details of harvesting - e.g., first or second lancing;

  4. Weight of the sample;

  5. Whether it is opium from one cultivator or several neighbouring cultivators;

  6. Local name of the variety of poppy;

  7. Other relevant data.

It was recognized that the foregoing details might not be available for authenticated samples of illicitly produced opium that might be confiscated and made available, but it was hoped that as much information as possible regarding those samples would also be furnished.

The Committee also decided to recommend that governments should be asked to furnish samples from opium seizures even in cases where they had not been able to authenticate them as having been produced within their territories. Such samples might indicate the existence of new opium types, and could be compared with one another and with the existing authenticated samples. Such information would also be of use to narcotics control authorities.

For establishing types, it was considered ideal that samples should be collected where possible from each of the producing localities for a period of five years; it was estimated that the total number of samples collected over this period would be approximately 1,000.


The Committee recognized that the requirements of laboratories participating in the research programme had to be distinguished from those which were solely engaged in making origin determinations on the basis of recommended methods. All active participants in the research programme should, so far as possible, have all the samples they requested made available to them.

As regards the "national" laboratories making origin determinations, it would be sufficient if they possessed a representative collection of samples including the principal opium types, although this collection would probably constitute only a relatively small percentage of the total number of authenticated samples that might be available.


The Committee reconsidered each of the methods which had been used or proposed for use in making origin determinations and evaluated each method in relation to its accuracy, reproducibility and usefulness for this purpose as well as the time, equipment and material involved in carrying out each method. These methods included both those in current use and others still under investigation by the scientists engaged in the United Nations programme.

The word "method" was defined as follows: "A method is an indication in outline of the characteristic or characteristics to be determined."

The following methods were reviewed and evaluated for purposes of establishing a scheme for opium origin determinations.


  1. Macroscopic Examination

The characteristics of opium, established by ordinary careful observation, were considered to be of value as a preliminary test.

The following points should be considered:

Kind of sample: Raw, extract, marc, etc.;

Adulteration:Hairs, bark, etc.;

Colour:Light, medium, dark-brown, black, etc.;

Form:Lumps, powder, sticks, moulded cakes, etc.;

Texture:Dry, irregular or smooth fracture, oily, presence or absence of leaves or bits of straw and soil, etc.;

Covering:None, leaf, paper, etc.;

Odour:Normal, sour, of ammonia, etc.

  1. Microscopic Examination

The advantages of the microscopic examination were its rapidity, simplicity and use of little material and readily available equipment. The test had always to be used in conjunction with other methods of origin determination.


  1. Unified Methods for Alkaloidal Determination

At least three unified methods had been devised for the determination of morphine, codeine, thebaine, papaverine, narcotine, porphyroxine-meconidine and minor phenolic alkaloids. The Committee decided that for present purposes it would adopt the method as described in document ST/ SOA/SER.K/34 entitled "A Unified Analysis of Opium for Alkaloids".

The results so far available for the five major alkaloids were of considerable diagnostic value, and would become more important as additional data accumulated. Although the absolute values of the individual alkaloids were regarded as important, the relative quantities of alkaloids and the ratios of one alkaloid to another yielded more useful diagnostic information.

The Committee noted the improved separation of papaverine and narcotine by use of ammonium reineckate, and learned that this method would be reported on in due course.

  1. Paper Chromatography and Paper Electrophoresis

There have been advances during the last several years in the techniques of paper chromatography applied to opium; these methods have the advantage of being rapid, requiring little complicated apparatus and small amount of sample. The methods might be divided into two groups: (i) those which give qualitative results; (ii) those which give quantitative values.

  1. Qualitative Paper Chromatography and Electrophoresis

These methods enabled qualitative comparisons of several opium samples to be made at one time, and thereby gave useful information for the determination of type. The value of the simple paper chromatographic and electrophoretic procedures was that they provided the analyst with many points of comparison on an opium sample which were useful for the general purpose of opium origin determination.

The Committee noted the usefulness in opium analysis of the simple chromatographic and electrophoretic methods.[5]

  1. Quantitative Paper Chromatography and Electrophoresis

Recent contributions on quantitative paper chromatography and paper electrophoresis had been received. These publications dealt with the analysis of total extracts of opium and of solutions containing all the alkaloids isolated from opium, in combination with spectrophotometry and densitometric determinations of the alkaloids.

These methods were rapid, required small samples, and provided a visible quantitative record of the different constituents. In addition, the analyst could handle a large number of samples in a single operation.

The accuracy and reproducibility of those methods remained to be determined, but the Committee was of the view that they would be of considerable value in the determination of opium types and in opium research generally.

  1. Direct Ultraviolet Absorption Spectrophotometry

Direct ultraviolet absorption spectrophotometry of solutions of opium [6] was studied in considerable detail. The Committee noted the distinction between the use of direct ultraviolet absorption spectrophotometry and spectrophotometry in conjunction with chromatographic and other procedures.

The direct ultraviolet absorption spectrophotometry might be usefully applied to the discrimination of opium types, but required further study. The method had been shown to be simple and rapid, and required small amounts of sample. The reproducibility between laboratories could be determined by collaborative assay.

The relationship of the ratios of extinction values and their correlation with origin were considered.

  1. Simple Colour Reactions

A preliminary report [7] had been presented on a method which depended on developing colours with various chemical reagents under specified conditions and measuring the colour intensity numerically.

The Committee considered that the advantages of the method were that it was short and simple, and required no separation of the opium constituents. The method was useful and promising, and should be studied further to determine its reproducibility and reliability for purposes of opium determination.

  1. Methods for determining Other Organic Components

After discussing the determination of nitrogen in opium and in certain opium fractions by the Kjeldahl method [8] and the analysis of opium for meconic acid and other organic constituents such as lipids, amino acids, the Committee thought that except as regards meconic acid and nitrogen, there were insufficient data for the purpose of evaluating the relationship between opium origin and the concentration of the other organic constituents of opium referred to in this sub-section. The ratio of narcotine to meconic acid might be of value in determining the origin of opium, but further work on this aspect was necessary.


It was observed that not all laboratories were furnished with spectrographic equipment and trained personnel to use this equipment, but that most laboratories had flame photometers, and for that reason the determination of potassium, calcium and phosphate in the ash would be possible. Although the methods were fundamentally the same, a distinction was made on the basis of the equipment used in each method.

The procedures for the ash methods were considered under the following headings: Preparation of sample; Flame photometry of the major elements; Colorimetric determination of phosphate; Spectrography of the major and minor elements.

Preparation of Sample

It was observed that the ash sample might be prepared either by dry calcination or wet decomposition in either platinum or silica dishes. The Committee decided that for purposes of opium origin determination, the dry calcination procedure was probably satisfactory if the temperature of calcination did not exceed 450°C. It was pointed out that in certain cases there could be loss of copper or phosphate in dry ashing procedures. However, this loss had not been established in the case of opium.

The Committee felt that for purposes of the collaborative tests on the method, the dry ashing procedure should be followed.

Recorded literature [10] showed that there was no loss of phosphorus in the opium dry ashing procedure.

Flame Photometry of Major Elements

The flame photometric method was very useful for purposes of establishing the origin of opium, and its accuracy was comparable with standard chemical procedures. The question of interaction of potassium, sodium and calcium and its effect on the accuracy of the results was also considered. It was noted that the published data [11] had been corrected for such interactions. It was pointed out that it would be advisable for laboratories undertaking flame photometry to participate in the collaborative assays for purposes of comparison of data from individual laboratories. It was essential that this method should be used in conjunction with other methods when establishing the origin of opium.

The Committee noted that it had been found possible to correlate very closely the origin determination by the composition of the ash with the origin determination by alkaloidal composition and other chemical methods. However, opium whose ash was abnormal due to special phenomena such as adulteration, contamination or the effect of fertilizers might be found. If such unusual results were observed, allowance would have to be made for them.

No data were available regarding the effect of artificial fertilizers on the ash of opium. It was not known whether the use of artificial fertilizers would bring about any appreciable change in the composition of ash, but if such changes were reported in the case of authenticated samples of opium, due note would have to be taken thereof in using this method for the determination of the origin of opium.

Colorimetric Determination of Phosphate

The ratio of potassium plus calcium plus sodium divided by phosphate (expressed in equivalent percentages) and the ratio of potassium divided by phosphate (expressed similarly) were valuable criteria for the determination of the origin of opium.

Spectrography of Major and Minor Elements

The spectrographic method for the determination of the major and minor elements present in opium ash had been useful in providing additional information for purposes of establishing the origin of opium when used in conjunction with methods for the analysis of other opium constituents. The equipment required for the procedure was expensive and not available in many laboratories, and therefore the use of the spectrograph was not made obligatory in the tentative scheme for establishing country of origin.


The Committee agreed that it was now possible to make determinations of a limited kind of the origin of opium by interpretation of available data. Since there was no single method which would itself satisfactorily establish the origin of opium, it was necessary to use the results of several methods or combinations of methods to establish origin. The Committee therefore decided that it would try to develop a tentative scheme for establishing the country of origin of opium (draft code of reference for the use of participating laboratories):

The Committee gave consideration to all of the methods that had been published to date for this purpose.


A. Initial Procedure

Documentary information: Recording of the documentary information concerning the sample on punch card or report form.

  1. Opium sample numbers

    The three cells of the punch card set aside for numbering should show:

    1. In the case of samples of seized opium, the number allotted by the country which made the seizure, the United Nations Laboratory number, and finally the number allotted by the laboratory which makes the analysis;

    2. In the case of authenticated samples, the first number should be that allotted by the country in which the opium was produced. The other two numbers would be as in ( a) above.

If necessary, other numbers allotted to the sample should be quoted - e.g., the case number.

The data should be entered in indelible ink.

  1. Dates

    1. Sample received in laboratory;

    2. Sample origin determined;

    3. Sample origin reported.

  1. Country and locality of origin for authenticated samples and, in case of contraband samples, place of seizure

  2. Informative data, sample history and description

    1. For each seizure sample, an abbreviated case history;

    2. For each authenticated sample, details of crop year, lancing, poppy variety;

    3. For evidence of origin, separate the authenticated samples for which full information can be given and state, if possible, the circumstantial evidence of origin for seizures.

B. Preliminary Analytic Steps

Macroscopic examination (see above, p. 39). Preparation of sample for analysis: breaking up and drying of the sample at a temperature between 60°C and 70°C until completely dry so that it can be pulverised in a mortar.

C. Methods

Microscopic appearance.

Simple chromatography on paper.

Unified analysis and/or short methods, British Pharmacopoeia method, Anneler method, ammonium reineckate method.

Electrophoresis, a method recently described,[12] which might prove useful in determination of origin when studied further. It seems to offer the possibility of comparing a number of samples at the same time.

Simple colour reactions (see above, p. 40).

Direct ultraviolet absorption spectrophotometry (see above p. 40).

Kjeldahl nitrogen method (see above, p. 41).

Ash methods (see above, p. 41).

D. Record of results of analysis

It was essential for the establishment of opium types and origin determination on seized opiums to adopt the same procedure for recording analytic results in all laboratories.

E. Interpretation of Data: Alternative Systems for classifying Opium Types

One of the essentials necessary for the determination of the origin of unknown samples that may arise in contraband traffic was to establish types of authenticated samples from different countries. For this purpose it was essential that the scientists should have at their disposal as much qualitative and quantitative data as possible of each authenticated type. All the data that were collected must be recorded so that they could be readily employed for assigning any type that they may come across in the course of analysis. Four of the possible methods of arranging the data and of arriving at a conclusion about the correct type are listed and described briefly below:

  1. System of description;

  2. System of classification or alphabetical coding;

  3. System of alternatives;

  4. System of correspondence.

In the following paragraphs, a brief description of each system is given.


  1. The System of Description

This system consists of writing descriptions of the types of opium to be provisionally recognized on the basis of existing data, emphasizing their differences and distinctive points. Each new authenticated sample is examined to see whether its outstanding characteristics conform to one of the provisional types, or whether they are significantly different. This system is thus analogous to the botanical classification of plants. It appears to be relatively simple, although it will be necessary to provide a uniform nomenclature for description. This would presumably be done on a collaborative basis.

  1. The System of Classification or Alphabetical Coding

In this case, the opium samples that have been analysed are provisionally classified by means of graphs which show the relationship between two or more sets of characteristics. The total area of the graph is subdivided into convenient sections by means of lines between the points and each of these sections is given a code number or a letter. The data for newly authenticated samples are then translated into the appropriate code on the basis of the analytical value, in order to see whether they have the same complete code designation. For example, the letters A J S might designate particular areas of the Calcium-Ratio 1 Chart.[13] One difficulty involved in the use of this method is the fact that some samples may lie close to the subdivision lines on the charts. It also sometimes operates to give a newly authenticated sample, a previously unused code designation, which may or may not mean that it is a new type. The method of coding may have to be developed further, when more samples have been examined.

  1. The System of Alternatives

This system consists of trying to find out how the results obtained on a new sample fit into the various groups of data within the existing groups, and to see that each sample fits as many points as possible for a given type.

  1. The System of Correspondence or Matching

This system of establishing identity of an unknown is the best known method, and is used universally in the field of organic analysis. It consists of matching the properties and characteristics of an unknown with those of the standard or reference. The punch-card method is based on this method of identification, and carries out the procedure in a mechanical way.[14] When the ranges have been determined, the procedure is automatic. Each newly authenticated sample is then "matched" in accordance with the prescribed rules of sorting. Some newly authenticated samples will have no corresponding known matching samples, in which case they would have to be established as belonging to new types.

The Committee decided that the essential methods would be listed, and that these methods would be considered as mandatory for any laboratory which desired to carry out opium origin determinations and which possessed the necessary equipment. The essential methods were divided into two groups on the basis of the availability of equipment for carrying them out.

The first group, consisting of methods which could be carried out by all laboratories, comprised:

  1. A punch-card method for facilitating a record of documentary information and analytical data;

  2. Macroscopic examination;

  3. Microscopic appearance;

  4. Unified analysis of major opium alkaloids, including morphine, codeine, thebaine, porphyroxine-meconidine, papaverine and narcotine.

The second group of methods, which at present could be carried out only by laboratories having the necessary facilities, comprised :

  1. Spectrography;

  2. Direct ultraviolet absorption spectrophotometry;

  3. Electrophoresis;

  4. Quantitative paper chromatography.

In view of the fact that these methods are considered to be of equal importance to those included in the first group, the Committee decided to recommend strongly that the various governments concerned should be invited to acquire the equipment and to train or acquire the personnel needed to carry them out.

The Committee emphasized the necessity for developing simple methods which should be of use to all laboratories, and considered that the method of simple colour reactions [15] showed considerable promise because of its inherent simplicity and should be tested on all authenticated samples as a routine procedure. It was noted by the Committee that a punch-card system had been used for purposes of relating simple colour reactions to origin of opium.

The Kjeldahl method for the determination of nitrogen in opium and fractions of opium was also considered of use in origin determinations.

It was emphasized that the four methods included in the first group should be used in combination with any of the other methods which were available to a given laboratory. It was contemplated that many of these methods would be evaluated by means of collaborative studies, and the results of such studies might make a re-evaluation of the methods necessary.

The Committee emphasized that it might be possible to replace some of the longer and more involved methods with simpler ones, and noted that important research was going on with this object in view.


The Committee felt that the results of past research had led to a point where limited application - in the sense that the conclusions had to be considered provisional in many cases - was possible, and observed that the United Nations Narcotics Laboratory was well equipped with facilities for carrying out origin determinations (practical application) and research work. In the organization of the work programme, it was suggested that some equitable division of efforts be made between practical application of known methods and research for the improvement and extension of methods and the discovery of new ones.

As regards the work of the national laboratories, the Committee wished to encourage each of them to collaborate in the undertakings suggested in this report - e.g., collaborative studies - and also to extend their work in those directions in which they were particularly interested and skilled. The national laboratories were also invited to report their results in papers which should give as much detail as possible of the scientific procedures employed, and should conform with the mode of presentation of contributions to publications within the country from which the paper was submitted.

The Committee distinguished between three major fields of work in each laboratory, as follows:

A. Collaborative studies;

B. Practical application of methods to establish the origin of illicit samples of opium;

C. Research on methods.


To establish the precision and reproducibility of the unified analysis method, the spectrographic and flame photometric methods, the direct ultraviolet absorption spectrophotometric method, and simple colour reactions method, the Committee decided that the participating laboratories and the United Nations Narcotics Laboratory should undertake collaborative studies of these methods.


It was noted that practical application was being carried out in national laboratories, and that it would have to continue. It was also felt that the United Nations Laboratory should carry out origin determinations, but that these might generally be restricted to those samples on which there was a divergence of views and to those samples sent by governments which did not possess their own testing facilities. It was also pointed out in discussions that some national laboratories might wish to send samples of illicit opium either to other national laboratories for consultation or to the United Nations Laboratory as a reference case. Samples of seized opium which had been analysed by the national laboratories and the United Nations Laboratory should be retained for a very long time before they were destroyed or otherwise disposed of.


The Committee found that it was difficult for participants in the programme to keep informed of the kind of research that was being carried out in each of the national laboratories. It defined, therefore, the several broad fields of work as follows: (i) research towards simplification of established methods; (ii) research on means of classifying characteristics with a view to establishing opium types; and (iii) preparation of a book of methods for opium origin determination.

As for the role of the United Nations Narcotics Laboratory, it was pointed out that it maintained an opium distribution centre, and distributed the scientific papers which were published in the ST/SOA/SER.K/... series. It was felt that the United Nations Laboratory should carry out enough analyses on seizures to keep in touch with the methods which were being developed in the total programme, and that it should endeavor to supply data in the best possible form for use of the national laboratories. In regard to the distribution of research problems among the participating groups, it was considered that the Secretariat could make a valuable contribution by issuing annual progress reports. This would enable the participants to evaluate their own research programme in relation to programmes being carried out in other countries. It should be possible for the Secretariat to give some advice in the establishment of priorities in respect to research problems. On request of participants in the research programme, the Secretariat could suggest problems which it thought were of importance. It was felt that in order to facilitate this it would be best for the Secretariat to examine the current publications in the ST/SOA/SER.K/... series, and to try to establish the specific fields in which research was being carried out. The Committee realized that the tasks of the national laboratories in most cases were multiple, and that opium research constituted one of a number of tasks which those laboratories had to carry out.

The question was also raised whether financial assistance could be provided in support of research work undertaken in participating laboratories for the benefit of the United Nations programme.


See also on that subject the three following articles in the Bulletin on Narcotics : " Determining the origins of opium " (Vol. I, No. 1);


Resolution 262 H (XXII), Twenty-second Session of the Economic and Social Council, 2 August 1856.


The following data are based on information circulated in United Nations documents - e.g., annual reports of governments, reports of the Permanent Central Opium Board - and on information provided by the participants or by the previous committee of experts.


In the meantime, a note has been received from the Government of Afghanistan transmitting officially to the Secretariat of the United Nations the text of a law of 24 November 1957 concerning the prohibition of cultivation, trade, purchase, sale, import, export and use of opium in Afghanistan; the cultivation of the opium poppy and the export of opium will henceforward be prohibited (doc. E/NL.1958/13).


A Study of Paper Chromatography, by G. Panapoulos & A. Vassiliou, Greece, ST/SOA/SER.K/27; Supplementary Study on the Method for the Determination of Origin of Opium based on Paper Chromatography, by G. Panapoulos & A. Vassiliou, Greece, ST/SOA/SER.K/37; A supplementary Study of Paper Chromatography for the Determination of the Origin of Opium, by G. Panapoulos & A. Vassiliou, Greece, ST/SOA/SER.K/42; Chromatographic Analysis of Opium, its Alkaloids and Synthetic Narcotics for Identification Purposes, by C. G. Farmilo, K. Genest, E. G. Clair, G. Nadeau, G. Sobolewski & Miss L. Fiset, Canada, ST/SOA/SER.K/58; Paper Electrophoresis of Opium and its Use in solving Opium Origin Identification problems, by C. G. Farmilo & W. P. McKinley with J. C. Bartlet, Mrs. P. Oestreicher & Mrs. A. Almond, Canada, ST/SOA/SER.K/61.


The Determination of the Origin of Opium by Means of Ultraviolet Absorption Spectrophotometry, by L. Grli & J. Petricic, Yugoslavia, ST/SOA/SER.K/48; Determination of the Origin of Opium by means of Ultraviolet Absorption Spectrophotometry, II, by. L. Grlic, Yugoslavia, ST/SOA/SER.K/54.


A Preliminary Report on the Use of Colour Reactions for determining Origin, by United Nations Secretariat, ST/SOA/SER.K/65 and Corr. 1.


A Study of the United Nations Samples of Opium, by G. Panapoulos & A. Vassiliou, Greece, ST/SOA/SER.K/16.


The Determination of Countries of Origin of Opium Samples by means of the Composition of the Opium Ash, by J. C. Bartlet & C. G. Farmilo, Kanada, ST/SOA/SER.K/30; Spectrographic Analysis of Opium Ash, by United Nations Secretariat, ST/SOA/SER.K/63.


"Studies on the Ash Constituents of Indian Opium" from Memoirs of the Department of Agriculture in India, Chemical Series, 8, 45, (1925-1927), by H. E. Annett & M. N. Bose.


The Determination of Countries of origin of Opium Samples by means of the Composition of the Opium Ash, by J. C. Bartlet & C. G. Farmilo, Canada, ST/SOA/SER.K/30; Tabulation of results of Physical and Chemical Analyses of Authenticated Opium Samples, by United Nations Secretariat, ST/SOA/SER.K/41; Further Alkaloidal and Opium Ash Composition data for Determination of Opium Origin, by C. G. Farmilo, J. Bartlet, P. Oestreicher & A. Almond, Canada,ST/SOA/SER.K/47.


Paper Electrophoresis of Opium and its use in solving Opium Origin Identification Problems, by C. G. Farmilo & W. P. McKinley with J. C. Bartlet, P. Oestreicher & A. Almond, Canada, ST/SOA/SER.K/61.


The Determination of Countries of Origin of Opium Samples by means of the Composition of the Opium Ash, by J. C. Bartlet & C. G. Farmilo, Canada, ST/SOA/SER.K/30, fig. 10, p. 34.


A Punched-card Method for Opium Origin Determinations, by J. C. Bartlet & C. G. Farmilo with G. Taker, Canada, ST/SOA/SER.K/56.


A Preliminary Report, on the Use of Colour Reactions for determining Origin, by United Nations Secretariat, ST/SOA/SER.K/65 and Corr. 1.