A laboratory approach to the control of cocaine in Bolivia

Sections

ABSTRACT
Introduction
Analysis and identification of cocaine and related substances
Characteristics of samples analysed
Distribution of samples
Conclusions

Details

Author: MERCEDES MORALES-VACA
Pages: 33 to 43
Creation Date: 1984/01/01

A laboratory approach to the control of cocaine in Bolivia

MERCEDES MORALES-VACA Head of the Toxicology Laboratory, National Bureau for the Control of Dangerous Substances, La Paz, Bolivia

ABSTRACT

Of the 4,196 samples of drugs seized and analysed at the Toxicology Laboratory of the National Bureau for the Control of Dangerous Substances during the period 1975 - 1982, 3,768 samples (89.8 per cent) contained coca paste, cocaine hydrochloride or related substances. Most of the samples analysed contained coca paste and came from La Paz, Santa Cruz and Cochabamba. With a slight exception in 1980, the number of samples increased steadily over an eight-year period. The increase in the number of seizures of cocaine-related substances was a result of the growth in the illicit production of these substances, which began to assume larger dimensions in 1976. In many areas, coca-paste and cocaine-related problems are growing out of all proportion. The smoking of cigarettes that contain a mixture of tobacco and coca paste, popularly known as pitillos,is the most common form of drug abuse.

Introduction

In the present decade, there has been an unprecedented rise in the illicit production and marketing of cocaine in Bolivia. This is to some degree reflected in the growing number of seizures of cocaine and related substances by the National bureau for the Control of Dangerous Substances over the past few years, and in the even larger amounts involved. The resources available to law-enforcement agencies for combating the illicit drug traffic are negligible when compared with the enormous economic power possessed by the illicit drug-trafficking organizations.

The steady increase in the number of seizures of cocaine-related substances was a consequence of the growth in the illicit production of these substances, which, according to Bascopé [ 1] , began to assume large dimensions in 1976. This growth in production was, according to the same author, closely related to contemporaneous agro-industrial developments in the east of Bolivia. This view is shared by Canelas and Canelas [ 2] in their analysis of the socio-economic situation in the period 1972 - 1979 and the far-reaching effects of increased drug trafficking on that situation. The decline recorded in the number of seizures in the second half of 1982 does not, on the other hand, seem to be indicative of a drop in the production of cocaine.

Analysis and identification of cocaine and related substances

In Bolivia, suspect substances seized by the police agencies are analysed in the Toxicology Laboratory of the National bureau for the Control of Dangerous Substances [ 3] . In the period 1975 - 1982, 4,196 samples were analysed, 89.8 per cent of which consisted of cocaine and substances involved in its production.

Qualitative analyses are based on the morphological characteristics and physico-chemical properties of cocaine. Cocaine shows a typical turquoise blue colouration in the presence of cobalt thiocyanate, characteristic crystalline structure as revealed by Popoff's reagent, and it can also be identified by means of thin-layer chromatography (TLC).

The detection of cinnamoyl-cocaine, an impurity which is found in illegally produced cocaine, pointed to the use of unsophisticated manufacturing methods. benzoyl-ecgonine, tropacaine and ecgonine were also detected. Ions from the acids and bases used in the production of cocaine and adulterants added at the marketing stage were also identified.

It should be noted that the Toxicology Laboratory is equipped only with basic devices, and has no modern, sophisticated apparatus. Nevertheless, by properly combining the classic testing techniques, it has been possible to carry out analyses that meet the needs of the bureau, as well as legal requirements, in this particular field of expertise.

Cocaine, or methyl ester of benzoyl-ecgonine is extracted from the leaves of the coca bush ( Erythroxylum coca Lam.) and other related plants. It can also be produced by synthesis from ecgonine. Cocaine was first isolated by Niemann, who gave it its name [ 4] .

In appearance, cocaine is a crystalline powder the colour of mother-of pearl, with an aromatic scent. Cocaine hydrochloride is used for medical purposes, especially in ophthalmology. It has the properties of a psychic excitant and local anaesthetic, acting on the central nervous system as a stimulant and on the autonomous nervous system as a sympaticomimetic [ 5] .

Cocaine is mainly inhaled, sniffed, injected or smoked. both cocaine hydrochloride and cocaine base are smoked, but the latter, being more volatile, is much preferred by drug abusers [ 6] . Hand-made cigarettes containing cocaine and cannabis are smoked [ 7] . The habit of coca-paste smoking in particular, is widespread in Bolivia and involves a highly distinctive ritual [ 8] . The most common form of abuse is the smoking of cigarettes containing a mixture of tobacco and coca paste, known as pitillos ,practised by 3 per cent of the population, compared with the 2.3 per cent who inhale cocaine hydrochloride [ 9] . Coca paste may also be smoked in tocos, that is, in pipes fashioned out of tin foil and stuffed with one layer of coca paste and another of tobacco. Cocaine base obtained from cocaine hydrochloride is smoked in small pipes or mixed with tobacco [ 10] .

The cocaine hydrochloride illegally sold at the street level is usually adulterated and "cut" (decreasing its purity), and is known as "street cocaine"; it contains such diverse substances as local an aesthetics (lidocaine, tetracaine and procaine), sugars (mannitol, glucose and lactose) and other substances, such as caffeine, amphetamines and heroin [ 11] .

The substances seized throughout the country by law enforcement officials of the National bureau for the Control of Dangerous Substances are sent to the Toxicology Laboratory for analysis, and samples are then placed in a labelled polyethylene envelope with a request for technical work.

Once in the laboratory, the samples are weighed, logged and subjected to the following tests:

Solubility: in water; in chloroform; in methanol

Measurement of pH

General alkaloid reactions

Ion identification

Cobalt thiocyanate reaction

Microcrystallization test: with Popoff reagent; with platinum chloride

The analyses are carried out in a 2 per cent aqueous solution, except for TLC, for which a methanol or chloroform solution is used. These tests determine whether cocaine and its impurities are present and also whether the cocaine occurs in salt of free-base form.

It can be seen from the following figures that the number of samples of cocaine and related substances analysed in the Toxicology Laboratory increased sharply in the period 1975 - 1982, with the exception of 1980, when there was a slight drop.

Year

Number of samples

1975 103
1976 194
1977 254
1978 333
1979 628
1980 571
1981 704
1982 982

It should be noted that, following the establishment of the Toxicology Laboratory towards the end of 1974, the yearly rise in the number of samples of cocaine and related substances examined reflected the growing number of seizures of these substances.

After the samples had been tested they were classified into the following five groups: coca paste; cocaine hydrochloride; substances used for the production of coca paste and cocaine; mixtures; and pitillos.These terms are defined as follows:

Coca paste, or cocaine paste, is a powdery amorphous substance of complex composition and is also known as "cocaine sulphate" or "sulphate base". The latter designations may possibly have been adopted because sulphuric acid is used in the production of coca paste, and although they are not strictly speaking correct, coca paste is commonly referred to in these terms in police and newspaper jargon. The correct name is coca paste [ 12] , since the substance consists of cocaine base, ecgonine, benzoyl-ecgonine, tropacocaine, cinnamoyl-cocaine, sulphates and carbonates [ 13] . Its litmus reaction is alkaline or basic, which is why it is known in some areas as basic paste [ 14] . Coca paste is an intermediate product in the production of cocaine hydrochloride [ 15] .

Cocaine hydrochloride is a crystalline powder, which usually shows an acid reaction to the pH indicators and is soluble in water.

Substances used for the production of coca paste and cocaine encompass coca leaves, kerosene, sulphuric acid, ammonia, carbonates and other substances used for this purpose.

Mixturerefers to a sample containing a combination of cocaine hydrochloride or coca paste with another substance or substances, such as local an aesthetics.

Pitillos are cigarettes prepared from a mixture of coca paste and tobacco.

Characteristics of samples analysed

Coca paste

Coca paste occurred in the form of an amorphous-looking powdery or pasty substance with colours ranging from white to drab and passing through browns and yellows. In the period between 1975 and 1980 it was found in the form of a moist paste in 23.5 per cent of the samples and between 1981 and 1982 in 65 per cent of the samples.

In a large proportion (94.3 per cent) of the paste samples taken, the pH was alkaline. Most samples were insoluble in water, whereas more than half of the samples (53.1 per cent) dissolved in chloroform. The analysis of coca paste samples showed the presence of inorganic salts, such as carbonates, sulphates and ammonium salts. ln addition to cocaine, analyses by TLC revealed the presence of benzoyl-ecgonine, ecgonine and tropacocaine. In these analyses, methanol ammonia was used as the mobile phase, silica gel G as the absorbent, and the modified Munier reagent as the developing spray reagent.

On the basis of the discolouration of the potassium permanganate [ 16] , the presence of cinnamoyl-cocaine was detected in 93 per cent of all the samples of coca paste analysed.

Cocaine hydrochloride

The cocaine hydrochloride sample was of a fine consistency, almost always white or whitish in colour. The substance was moist in only 7 per cent of the samples.

A large proportion of the samples analysed (97.4 per cent) exhibited an acid pH factor; 94.2 per cent were soluble in water and 64.2 per cent in chloroform. Cinnamoyl-cocaine was detected in 80 per cent of the samples. In addition to the chloride ion found in all samples, sulphate and carbonate ions were also detected in some of them.

TLC revealed the presence of cocaine and benzoylecgonine; the latter was detected in only a small percentage of the samples.

Substances used for the production of coca paste and cocaine

The substances used for the production of coca paste or cocaine hydrochloride were obtained by the police from the seizures of clandestine laboratories. An analysis was made of acids, alkalis and organic solvents, the sale of which is currently controlled; coca leaves, which were generally impregnated with the substances mentioned above and/or with kerosene, were also analysed.

Table 1

Substances used for the production of coca paste and cocaine hydrochloride: number and percentage of samples analysed, 1975-1982

Substance

Number of samples

Percentage of total

Coca leaves
21 4.6
Coca leaves impregnated with other substances
209 46.1
Kerosene
21 4.6
Sodium carbonate
100 22.0
Calcium carbonate
10 2.2
Ammonia
19 4.2
Sulphuric acid
34 7.5
Sodium bicarbonate
3 0.6
Hydrochloric acid
6 1.3
Acetone
15 3.3
Ethyl ether
2 0.4
Potassium permanganate
13 3.0

Of 453 samples, the largest number contained coca leaves, followed by sodium carbonate, sulphuric acid, kerosene and ammonia, as can be seen from table l.

Mixtures

Mixtures of coca paste or cocaine hydrochloride with other substances accounted for 247 samples, in the following combinations:

(a Coca paste and calcium (or sodium) carbonate,

  1. Coca paste and flour,

  2. Cocaine hydrochloride and sodium bicarbonate,

  3. Cocaine hydrochloride and procaine,

  4. Cocaine hydrochloride and benzocaine,

  5. Coca paste and cocaine hydrochloride.

The substance most commonly detected in coca paste was sodium carbonate, followed by flour. The substance most frequently mixed with cocaine was sodium bicarbonate, followed by procaine and benzocaine.

The mixtures of coca paste with sodium and calcium carbonate were similar in appearance and colour to the pure paste. Such combinations were characterized by an abundance of carbonate ions and poor solubility of the paste in either water or chloroform.

Table 2

Mixtures of coca paste or cocaine hydrochloride with other substances : number and percentage of samples analysed, 1975-1982

Mixture

Number of samples

Percentage of total

Coca paste and sodium or calcium carbonates
126 51.0
Coca paste and flour
72 29.2
Cocaine hydrochloride and sodium bicarbonate
29 11.7
Cocaine hydrochloride and procaine
12 4.9
Cocaine hydrochloride and benzocaine
5 2.0
Cocaine hydrochloride and coca paste
3 1.2

Mixtures of coca paste with flour had the appearance of a white or yellow homogeneous and amorphous powdery substance, which was virtually insoluble in water or chloroform. Corn-starch and wheat-starch cells were detected.

The mixtures of cocaine hydrochloride with other local an aesthetics exhibited characteristics of colour, appearance, pH and solubility similar to those of the pure cocaine hydrochloride. With TLC an additional spot was observed, which, when treated with the Van Urk reagent [l7] was found to be procaine and benzocaine.

Pitillos

Pitillos were found as filter cigarettes containing tobacco mixed with a white powder. In every case the powder was coca paste and exhibited the proper ties already noted.

Distribution of samples

Annual distribution

Table 3 shows that, except for 1981 , the number of coca-paste samples increased steadily from 1975 to 1982, with a particularly sharp rise in 1982- The number of samples of cocaine hydrochloride peaked in 1979 and then followed a zig-zag pattern, until the lower point was reached in 1982. The substances used for the production of coca paste and cocaine hydrochloride reached a peak in 1981 , and then fell suddenly in 1 982. There was a marked increase in the number of samples containing either coca paste or cocaine hydrochloride mixed with other substances.

Table 3

Coca paste, cocaine hydrochloride and related substances : number of samples analysed, 1975-1982

Substance

1975

1976

1977

1978

1979

1980

1981

 
Coca paste
42 62 116 221 346 441 401 738
Cocaine hydrochloride
59 92 86 54 160 61 103 29
Substances used for the production of coca paste or cocaine
2 40 45 55 71 51 129 60
Pitillos
-
-
-
3 40
-
4 6
Cocaine hydrochloride and procaine
-
-
6
-
6
-
-
-
Cocaine hydrochloride and benzocaine
-
-
1
-
2 2
-
-
Cocaine hydrochloride and sodium bicarbonate
-
-
-
-
-
6 13 10
Coca paste and flour
-
-
-
-
-
5 33 34
Coca paste and sodium (or calcium) carbonate
-
-
-
-
-
-
21 105
Cocaine hydrochloride and coca paste
-
-
-
-
3
-
-
-
Cocaine in the course of productions
-
-
-
-
-
5
-
-

a These samples contain certain coca alkaloids in addition to those found in the samples of cocaine hydrochtoride or coca paste.

Geographical distribution

From table 4 it will be seen that most of the substances analysed at the Toxicology Laboratory during the period 1975 - 1982 were seized in the areas of La Paz, Santa Cruz and Cochabamba, accounting for 55.l per cent, 29.9 per cent and 14 per cent of the total number of samples.

Table 4

Number of seizures of coca paste, cocaine hydrochloride and related substances, by area, 1975-1982

Area

Coca paste

Cocaine hydrocloride

Substances used for the production of coca paste and cocaine

Pitillos

Mixtures

La Paz
1135 432 259 1 137
Santa Cruz
702 195 86 51 94
Cochabamba
439 10 60
--
18
Oruro
52
--
21
--
--
Beni
34
--
--
1 1
Chuquisaca
2
--
20
--
--
Tarija
1 7 7
--
--
Potosi
2
--
--
--
1

La Paz and Cochabamba are traditional coca-leafgrowing areas, so that the raw material is readily available. The proximity of Santa Cruz to the Cachare district probably accounts for the large number of samples originating there. The coca-leaf plantations in Beni were located in remote areas, surrounded by jungle, and could only be reached by air, which was probably why so few samples came from that area. Chuquisaca, Tarija and Potosí are cities with little economic activity, and are therefore of little interest to drug traffickers.

The substance most frequently analysed was coca paste, which was always present to some degree in seizures made by the district bureaux. The second most common substance was cocaine hydrochloride, although it was not found in all areas of the country. Next came the substances used for the production of coca paste and cocaine, followed by mixtures and finally by pitillos,most of which were seized in Santa Cruz, the city with the highest consumption rate of controlled substances [ 9] .

The largest number of samples was found in La Paz because it is economically and politically important, and thus attracts the attention of drug traffickers. A large number were also found in Santa Cruz, Bolivia's second-ranking city. In Cochabamba, coca paste accounted for most of the samples, indicating that production in this region is based on inexpensive materials and that producers have limited resources.

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Conclusions

The number of seizures of coca paste, cocaine hydrochloride and related substances in Bolivia, as reflected by the number of samples analysed, increased rapidly in the period l975 - 1982. This increase should be viewed in the light of: (a) an increase in illicit production ; and (b) more effective controls by law-enforcement officials.

Most samples analysed at the Toxicology Laboratory in the period 1975 - 1982 contained coca paste. The number of cocaine hydrochloride samples decreased in 1982, with a parallel increase in coca-paste samples.

The largest numbers of seizures, as represented by the number of samples analysed, came from La Paz, Santa Cruz and Cochabamba. These three areas had the largest economic and human resources, enabling considerable amounts of coca paste and cocaine to be produced and sold.

The largest number of samples of coca paste and cocaine hydrochloride mixed with other substances and of pitillos came from La Paz and Santa Cruz, where there were also a large number of abusers of these substances.

The number of samples containing substances used for the production of coca paste and cocaine decreased sharply in 1982. The decrease was associated with the stricter control exercised over the sale of these substances.

Cinnamoyl-cocaine was found in 80 per cent of the samples of cocaine hydrochloride and 93 per cent of the coca paste, indicating that unsophisticated equipment was being used for the production of these substances.

The difference in the number of alkaloids detected in coca paste samples was most probably due to differences in production methods or in the sources from which the samples were obtained. There were fewer alkaloids, such as cocaine, benzoyl-ecgonine, ecgonine and tropacocaine, in the samples obtained from La Paz than in the samples from Santa Cruz.

Coca paste was adulterated in ways that have not been reported in other countries, namely with different flours (corn and wheat), particularly in Santa Cruz. Mixtures with sodium carbonate and calcium carbonate were also observed, and many samples were found to contain gypsum. The obvious purpose of these mixtures was to increase the volume, and it was impossible to determine in the Laboratory at what stage the mixing took place.

In the period 198l - l982, an increased proportion of the coca-paste samples analysed was moist, coinciding with the increase in the number of seizures of this substance in the same period. As illicit production increased, the police discovered illicit laboratories in which the coca paste had been half dried, leaving no time to complete the manufacturing process.

The author believes that with better and more sophisticated equipment it will be possible to identify the sources of coca paste and cocaine. For example, the presence of different alkaloids in coca paste can provide a clue to the area in which it originated.

Coca paste and cocaine-related problems are beginning to grow out of all proportion and are spreading to many areas. It should be emphasized that, as long as there is an illicit demand, the supply is likely to continue. It is not only by destroying the age-old growing areas of the coca leaf that a solution will be found. What is required is an attack on the roots of this evil, which is not confined to the inhabitants of the Andean region alone. Cocaine-related problems are global and global solutions must also be found.

Acknowledgments

The author wishes to thank Mr. Raúl Bohrt, without whose encouragement and guidance it would not have been possible to complete this work. Thanks are also due to Mrs. Beatriz Rojas de Chávez, for her collaboration and support, and to professor Manuel A. Guatelli, for his encouragement and advice.

References

01

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02

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03

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04

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05

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06

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07

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08

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09

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10

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11

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12

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13

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14

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15

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16

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17

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