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Cocaine - A Natural Scourge

Cocaine is produced naturally in a plant but there is a lot of chemistry involved before it is snorted or smoked at a high cost to society.

While walking around the exhibit hall at an agricultural conference a few years ago, when we could still travel, I perused the usual displays of farming equipment and industry booths promoting various pesticide and fertilizer formulations. To my surprise, there were also a number of booths selling video surveillance equipment. Why would farmers be interested in these I wondered? A chat with a salesperson quickly brought on a forehead-slapping “aha” moment. Farmers use ammonia as a fertilizer that is stored in large tanks on the property. And ammonia is readily converted into ammonium carbonate, which is what illicit drug producers need to make “crack” a form of “free-base” cocaine. The video cameras are supposed keep an eye on the ammonia tanks and deter theft. But judging by the growth of cocaine use, the cameras have not had a great impact. In Canada, aside from alcohol, cocaine represents the highest cost to the criminal justice system. And let’s point out to the “natural is better” crowd that cocaine comes from a plant. But before it travels up people’s noses or is inhaled in its vapourized form, chemistry has to swing into action.

Cocaine is a natural component of the erythroxylum coca plant, the leaves of which have long been chewed by South American natives to provide stamina and a mild feeling of euphoria. Chewing the leaves with a bit of lime, calcium hydroxide, liberates the cocaine more readily. Today, coca plants are cultivated on large tracts of land, mostly illegally, in many South American countries before ending up in Colombia for processing into cocaine which is smuggled into the U.S. in a variety of ways.

The processing actually starts in primitive jungle labs close to areas where the “crop” is grown. The leaves are soaked in gasoline that extracts the cocaine from the leaves. The solution is filtered, treated with an acid to form a cocaine salt, and the acid layer is separated from the gasoline. That layer is treated with a base, usually baking soda, to yield an impure form of “free-base” cocaine. This is shipped off to Colombia for purification that involves heating the crude product in a solvent such as acetone or ethyl acetate to which concentrated hydrochloric acid is then added resulting in the crystallization of cocaine hydrochloride. Residual solvent is pressed out, and presto, powdered cocaine hydrochloride is ready to be snorted or dissolved in water and injected.

Although cocaine isn’t physically addictive in the sense that no symptoms are experienced on withdrawal, it is addictive in the practical sense since users are unwilling to give up the euphoria it provides. The drug boosts the activity of the neurotransmitter dopamine that has been termed the “feel-good” chemical. However, the good feeling is short term and puts the user on a path towards more frequent indulgence. This can have all sorts of consequences, including paranoia, aggression, high blood pressure and sensations such as a feeling that parasites are crawling under the skin. “Formication” is the interesting term used to describe this hallucination. Of course, crime also enters the picture because abusers need money to support their habit and criminals will do whatever it takes to meet the demand from which they profit. This often means proving a form of cocaine that can be smoked for a quick, intense hit.

Cocaine hydrochloride decomposes with heat so it cannot be smoked. Reacting it with a base converts it to “free-base” cocaine that is volatile and can be inhaled to produce a short, powerful high. If the hydrochloride is heated in a spoon with sodium bicarbonate, the free-base cocaine separates as an oily layer on top that can be skimmed off and left to harden into pieces that look like small stones. When these are put into a pipe and smoked they make a cracking sound, hence the term “crack cocaine.”

A purer form of free-base can be made by dissolving cocaine hydrochloride in a basic solution of ammonia and adding a solvent such as ether. The cocaine, liberated by the action of ammonia, dissolves in the ether layer that floats on top and can be separated. Heating the ether extract drives off the solvent and leaves behind the free-base cocaine. This can be a dangerous operation as comedian Richard Pryor discovered when he accidentally ignited the highly flammable ether while trying to evaporate it and burned himself seriously.

A great deal of effort has gone into slowing the entry of cocaine into North America and Europe. The dual aim is to curb substance abuse and reduce the crime associated with cocaine production, much of which is controlled by South American drug cartels. Ten years ago, Colombia began a project of aerial spraying of coca fields with the herbicide glyphosate (Roundup) to wipe out the plants. This was stopped in 2015 because of possible exposure of people to the chemical that had been declared by the International Agency for Research on Cancer (IARC) as a “probable human carcinogen.” However, the growing scourge of cocaine abuse is forcing the Colombian government to consider restarting the spraying in face of an opposition movement that claims glyphosate will pollute water and affect people’s lives.

Another problem has also cropped up. The emergence of what has been called “supercoca.” These are plants that are resistant to glyphosate and survive spraying. How these have come about is a bit of a mystery. Conceivably, farmers have used selective breeding to develop a strain that is herbicide resistant, but there is another frightening possibility. Coca plants may have been genetically modified in an underground lab to resist glyphosate, just the way that canola, soy and corn have been legitimately modified to defy the chemical. If “supercoca” becomes established, aerial spraying may only benefit the drug lords since the crop will be spared and yields increased since any weeds growing in the field will be wiped out.

While I’m obviously a big supporter of chemical education and genetic engineering, the production of pure cocaine and “supercoca” plants underlines how scientific knowledge can be a double-edged sword.



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