• 🇳🇿 🇲🇲 🇯🇵 🇨🇳 🇦🇺 🇦🇶 🇮🇳
    Australian & Asian
    Drug Discussion

    Welcome Guest!
    Posting Rules Bluelight Rules
  • AADD Moderators: swilow | Vagabond696

Testing coke

C

Complete Random

Bluelighter
Joined
Apr 24, 2003
Messages
136
I was wondering if there are any tests, beyond simply railing a line, that will identify cocaine. From what i've gather, the ez testers will only bring up cocaine as an amphetamine like substance, that not what i'm after. I'm not a big fan of identification by smell, numbing, colour etc... personally, i don't think these factors mean shit. Any concrete chemistry i can use?
 
i am quite sure there is a tester that gives you a definative %result available in the UK and maybe australia.
ill need to call on a friend to find out what he uses. later, unless someone else has the info.
 
Good question!

Field test reagents for the detection and identification of cocaine, crack and related narcotics do exist. One type I vaguely remember was based on a modified Scott reagent, which had other stuff added to 'reduce false positive' results and provided a sensitive positive result to levels of residue of the order of 10 micrograms (so-claimed by the manufacturer, heh).

The test I'm thinking of works by spraying reagent on a specially prepared collection swab: you swab the area you want to test (or a tiny sample of powder from a baggie etc) and then spray the reagent on and watch for colour change. From memory a positive result was indicated by a turquoise blue colour change.

This kind of tester is marketed to parents who want to snoop their kids - it's perfect, a pack of collection swabs and a can of reagent... just wander through their room, swipe likely surfaces and then spray a bunch of reagents at the paper til you get a colour change that lets you lynch your kids for drugs...

BigTrancer :)
 
Oh yeah, once you've found that it IS cocaine, you can test the purity (approximately) by doing a quick home kitchen crack bake with bicarb soda - but you generally have to be prepared to sacrifice a decent amount of charlie to get a reliable result...

BT
 
I believe it's a modified Cobalt Thiocyanate Reagent... turns light blue in the presence of coke or crack. It will also return a false positive if a number of other chemicals are present, including PCP.
 
ODC Bulletin on Narcotics (1975) - A simple sensitive specific field test for cocaine based on the recognition of the odour of methyl benzoate as a test product

Details
Author: Fred W. GRANT, William C. MARTIN, Ralph W. QUACKENBUSH
Pages: 33 to 35
Creation Date: 1975/01/01

A number of field tests for cocaine have recently been described (1, 2, 3, 4) all based on the blue colour arising from the addition of a cobalt thiocyanate reagent to the test substance. The method of Scott (3) was recently given prominence in a United States Department of Justice publication (5). This test was found to be specific to cocaine among a group of 18 commonly encountered drugs. It requires the use of three reagents in sequence, including concentrated hydrochloric acid, and the recognition of colour changes, the formation and redissolving of a precipitate, and the colouration of an immiscible organic phase. The specificity of this test has already been brought into question (4) and we suspect more instances of this type will follow.

We had reason to explore the specificity of 2 per cent aqueous cobalt thiocyanate in drug testing and found 22 of 55 representative drugs to give a pronounced blue colour indistinguishable from that derived from cocaine. Twelve drugs gave a weaker blue colour. Acetone, alcohol, and certain soaps and detergents also gave a positive test. The reagent appears to be responding to the hydrophobicity of the test substance, among other properties, since a correlation generally prevails between test result and the partition of the drug between an aqueous and immiscible organic phase. Positive responding drugs will test negative if sufficient water is present, either in the reagent or in the test specimen.

Another anticipated failing of the Scott test is in dealing with cocaine specimens containing insoluble excipients. As previously noted, the test involves the recognition of a liquid-liquid phase boundary and the formation and redissolving of a precipitate. This could prove difficult if not impossible to do with certain specimens.

For the above reasons, we feel that tests for cocaine based on cobalt thiocyanate will continue to show an unacceptable incidence of false positives and false negatives despite modifications in test conditions.

Rationale for a test for cocaine
As is typical of many drugs, cocaine&rsquos biological activity is not matched by a comparable degree of chemical reactivity. However, it is quite unique among commonly abused drugs in being a benzoate ester. While colour tests for this functional group are not available, the lower alkyl esters of benzoic acid have quite distinctive odours detectable at very low concentrations relative to the average colour test. The transfer of the benzoate function of cocaine from methyl ecgonine to methanol is readily accomplished in the presence of dry methanolic potassium or sodium hydroxide as is shown in the figure above. Evaporation of the excess methanol leaves a residue containing methyl benzoate (Oil of Niobe) readily apparent by its odour. The test will not work in the presence of water but it is sufficiently specific to be unaffected by the presence of other drugs or excipients. Since the test conditions are those of transesterification rather than esterification, benzoic acid itself does not respond.

*Presented by FWG at the Sixth Northeast Regional American Chemical Society Meeting, Burlington, Vermont, 19 August 1974.


The odour of methyl benzoate arising from the test being applied to acetate esters such as aspirin or heroin might have led to ambiguities in test interpretation but for the fact that methyl acetate is more volatile (B.P. 57°) than methanol (B.P. 65°) and will dissipate during the solvent evaporation step. The odour of methyl benzoate (B.P. 198°) should persist for hours at normal temperatures.

Tests based on odour detection are generally suspect if subtle qualitative or quantitative distinctions between odours are called for. However, distinctions of this type are not required in the test described here. It is being recommended for the following reasons:

* Over one hundred of a wide variety of drugs (6) were tested and found to give no odour of any kind. Cocaine and piperocaine alone were benzoate esters and therefore gave a positive test. Occasionally a weak fishy odour was noted when the test reagent released a low molecular weight amine, such as amphetamine, from its salt.

* Test sensitivity and specificity exceed those of existing field tests for cocaine. This allows cocaine to be detected in low concentration in the presence of excipients or other drugs. Water will interfere with the test so reagent and specimen should be kept dry.

* The simplicity of the test makes it admirably suited to field testing.

* It has proven to be the test of choice for the field identification of cocaine by local County and State Police.

Test description
Reagent. One gram of sodium hydroxide or potassium hydroxide is dissolved in 20 mls. of dry methyl alcohol. This reagent should serve its purpose for many months if kept in a tightly stoppered container to minimize methyl alcohol evaporation and access of moisture.

Procedure. The dry test specimen is thoroughly moistened with the reagent on a spot plate or other non-corroding surface, a few minutes allowed for the evaporation of the excess alcohol (heating is not required), and the odour noted.
Click to expand...

Quoted from the above Linked report, and references are contained there. Oh yeah for those curious people:

Methyl benzoate's is also called Oil of Niobe, and its chemical name is: Benzoic Acid Methyl Ester. It's a colourless to slightly yellow liquid with a sweet fruity odour. Apparently this is the odor that drug sniffer dogs can smell from cocaine.

Excerpted from a court testimony by an analytical chemist and forensic scientist: re: drug sniffer dogs and american currency.

[...]

2. It is my expert opinion that a positive alert to U.S. currency by a properly trained narcotics detection canine indicates that the currency had recently, or just prior to packaging, been in close or actual proximity to a significant amount of narcotics, and is not the result of any alleged innocent environmental contamination of circulated U.S. currency by microscopic traces of cocaine.

3. My expert opinion is not affected by the alleged theory that the majority of circulated U.S. currency is innocently contaminated with microscopic amounts of cocaine, as my research has shown to a reasonable scientific certainty that a narcotics detection dog alerts to the odor of methyl benzoate as the dominant odor of illicit cocaine, and not to pure cocaine itself.

4. The dominant cocaine odor chemical, methyl benzoate, is a highly volatile substance associated with the manufacture of illicit cocaine and evaporates quickly when handled and/or exposed to air, while pure cocaine hydrochloride has almost no gaseous odor and is transferred rather easily by physical contact. The very processes, which result in the contamination of currency by cocaine (including the handling and mechanical counting of currency), tend to dissipate the cocaine odor chemical, methyl benzoate.

5. Additionally, cocaine is a local anesthetic and as such blocks the transmission of nerve impulses. Therefore cocaine should block the transmission of olfactory (smell) nerve fibers resulting in non-detection.

6. It is also my expert opinion that the methyl benzoate found in some perfumes is so minute as compared to the many other gaseous substances contained in perfume that a narcotics detection dog trained to alert to cocaine would not alert to perfume.

[...]

8. I am also aware of numerous non-alerts by trained narcotics canines to large amounts of circulated U.S. currency, a fact which supports my theories and is inconsistent with the theory that all U.S. currency is contaminated with so much cocaine that narcotics detection canines will always alert to money.

From: Currency sniffs
Click to expand...

BigTrancer :)
 
Apparently Cobalt Thiocyanate also gives the same blue reaction to most other 'caines (Nocacaine et al), which unfortunately are commonly used to cut real cocaine.
 
Open the baggie, it should be opaque, even pinkish-white, not crystalline! Smell it... it should smell a bit like sassafrass (think root beer) or ginger (think Dr.Pepper). The true test is this: one dip into the baggie, apply to the top gum right between your front two teeth. Within seconds it should become cold and numb. The numbness should spread up to your septum. If 5 minutes go by and nothing, then no buy my friend. These factors are the rules that most Police forces in The U.S. use to identify your substance as cocaine versus something else, before they take it back home and do it...
 
before they take it back home and do it...
Click to expand...

Ah but can you really blame them? I've often wondered why anyone would want to be a cop, but maybe I've just figured it out....
 
Within seconds it should become cold and numb. The numbness should spread up to your septum. If 5 minutes go by and nothing, then no buy my friend.
Click to expand...

This is not a good method for determining coke content. The numbness potential of coke can be easily increased, and is commonly used by incorporating one of the so called "perfect" cuts. I once tasted a small amount of coke which was raved about by the owner. It instantly numbed my mouth tongue everything. But the odd thing was that the taste wasn't as bitter as coke, well not in the same way. After a fiddly procedure involving cleaning and basing, we concluded at the most there was 23-25% coke. Certainly not high grade IMO



When we made PABA (the suntan additive) at Uni in Org Chem II, the lab manual described another part to the exercise - to synthesize benzocaine by simple estification of PABA with ethanol.

However we were told we would not be crystallising any benzocaine. I hassled the lecturer all morning for a reason, but he just smirked and said nothing. As I was leaving the class he pulled me aside and said the reason is that in the past the product has had a tendency to disappear from class to reappear on the street cut with meth - selling as cocaine. Therefore, powerful anesthetic actions (numbness) should not be used as an infailable test for high purity.




The Cocaine ester (benzoate) group is interesting because it can be easily removed, or substituted for another ester / functional group altogether. This chemistry allows cocaine to be transformed essentially into something else, transported to it's destination then reconverted back to its original form

Example:

Ester + base (saponification) or weak acid hydrolysis --> Organic Acid

Organic Acid + Thionyl Chloride ----> Acid Chloride----> (infinite number of possible compounds from here - many reversible)

Acid Chloride + Benzoic Acid -------------> Ester

Any residual methyl benzoate is easily mopped up, if the chemist is suitably equipped i.e. not a jungle lab. I'm surprised more coke isn't processed as to remove this product. I would imagine methy benzoate occurs as a trans esterfication product from methanol used as a solvent.

An ester is normally a very versatile chemical group, and cocaine has 2 of them. The smells from apples, bannanas and pears are good examples of esters.
 
Ok, so according to BT's post, if i dissolve one gram of sodium hydroxide, which is common table salt, right??? with methyl alcohol which i'm guessing is methanol, a swanky name for metholated spirits... i would have a tester of sorts. I would then have to "dry-out" the sample on an oven warmed, ceramic plate, immerse my sample with the tester solution, wait a few minutes and smell whatever is left on my plate. If it smells fishy, there's something fishy present... if its sweet and fruity i'm on the money.

Phase_dancers post is a little more 'mindboggling.' If i mix my ester with a base then i get an acid. The more ester that is present the more acidic my final solution? So assuming that other chemicals that may be present, react/not react to form acids, would the final acidity of the solution give an indication as to the amount of ester that was intially present? A quantitative test? :\

Its been a long time since i've last seen an organic chemistry textbook.

cheers for the replies
 
bicarb test for coke purity

Sorry about the mindboggling. I wasn't actually suggesting using post reaction pH as measurement of purity. It seems like far too much work, although there is some merit to the idea....anyway I digress again - (slaps face and reminds self these 2-3am mornings will end post exam week when normal sleeping patterns return)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is probably the best you can hope to do without specialized stuff. To do better would require a bunch of different solvents, phys info on coke and some good lab technique. However, in the hands of an experienced person, this techniques can be done in the time it takes to make a good coffee (well OK then, if you had to grind the beans by hand!! ;)

First establish there is no amphetamine by testing it with Marquis. If there is, it will react the same as coke and add to the final weight.

Weigh 1 gram of speed free coke using scales with a resolution no less than 0.01 resolution. Ideally these should be 0.001 or better. Anyway, the commonly seen 0.1g gram scales are not suitable or you'll only get a purity factor + - 10% (e.g. 60-69.9% + or -1%). The more accurate the measurement, of course the more meaningful the result will be.

Next is to liberate the free base using sodium bicarbonate

Mix ~1 part bicarbonate to 3 parts coke. Put in a small glass vial and add ~5-10 ml of warm water. Heat in a water bath (pot on the stove). It will start to fizz, but keep heating until fizzing stops and all is dissolved. Jiggle it to help. What doesn't dissolve is not something you want anyway. If something is left, and just in case the amount of water is too low, add a few extra mls of water and rewarm, but don't overdo it.

Let it cool and small rocks (sometimes a single large one will crystallize out of solution. Wait until it is completely cooled and tip onto a paper towel and dry.

**Take these rocks and dissolve in a small amount of zippo lighter fluid. Filter and keep the fluid. Leave in the air to evaporate and the rocks will remain.

Weigh the rocks with the same accuracy of scale. Even if the coke was 99.999999999999% pure, it will now weigh less. This is normal. You have just taken off ~11% of the weight by removing the HCl part.

For arguments sake, lets say the freebase coke now weighs 0.65g

Multiply this by 1.12 to give the original weight of cocaine HCl as 0.72.8g. This means the coke was roughly 72.8% pure

To get your coke back to the sniffable salt, dissolve in zippo, stir while adding HCl drop-wise until crystals cease to appear. It's good idea to brush up on some basic crystallization techniques before attempting this.

Summary:

Weigh Coke

Add bicarb

Heat slowly not to boiling

Cool when fizzing ceases (put your ear to it and listen closely)

Dry rocks on paper towel

Dissolve in zippo, then filter and evap zippo**

Reweigh

Percentage purity = weight of freebase x 1.12 x 100%

Re- acidify if required

** This step can be omitted, or others included to remove a greater selection of possible contaminants.
 
Ok, so according to BT's post, if i dissolve one gram of sodium hydroxide, which is common table salt, right???
Click to expand...

Nope, table salt is sodium chloride (NaCl). Sodium hydroxide is NaOH, or caustic soda.

with methyl alcohol which i'm guessing is methanol, a swanky name for metholated spirits...
Click to expand...

Nope, methylated spirits is a mixture of ethyl alcohol (95 per cent) and methyl alcohol (5 per cent). The methyl alcohol is poisonous and is added to prevent the methylated spirits being used as cheap drinking alcohol.

wait a few minutes and smell whatever is left on my plate. If it smells fishy, there's something fishy present... if its sweet and fruity i'm on the money.
Click to expand...

Something like that - the fruity smell should persist for some time compared to other odours, so you don't have to smell it immediately if it appears to be giving off awful smells to begin with. Never put your nose directly near a chemical reaction to smell it, but rather 'waft' your hand over it to bring some of the smell to your nose from a distance away.

BigTrancer :)
 
Phase Dancer, so benzocaine, lidocaine and novacaine (cuts) are not hydrochloride salts and/or will not convert to freebase form with the same process?
 
Steve Electro, how did I know that was going to be the next question? :\


OK yes, you are right some compounds can potentially freebase and form salts too. When looking at the cocaine molecule, it can be seen that the amine (a tertiary amine) is located away from the ester groups on the tropane backbone. The only "caines" I know of like this (without the NHx next to a C=O) are Novocaine and benzocaine (tetracaine too but I don't think that is made any longer). Lidocaine is an amide so wouldn't form HCl salts the same way as the other 2 do. I don't know about proparacaine without looking further.

Edit: Remembered that benzocaine is not made as a HCl salt as it is not water soluble, so benzocaine would not be likely to be used with coke, despite what my lecturer claimed. Perhpas he knew of another application ;)

One way of establishing whether there is a significant amount of other compounds in the freebase rock is to do a melting point test.

NOTE: the FB would need to be recrystallised from ether (or zippo) prior to melting point test as described in my post above

The melting point temperature of freebase cocaine will generally be lower and broader if impure. If you had access to a spectrophotomer you could check the index of refraction. (second hand units are cheap if you know where to look. Check s/h scientific suppliers. They are NOT sus items.

From my old CRC book on phys constants of Cocaine FB:

Refractive index: SOLID alpha 1.49, alpha -15.83 (20deg C) in chloroform

Melting point: 98 deg C

Solubilities

Water: (grams/100ml of ) 0.16 @ 25 degC, 0.38 @ 80 degC

Alcohol: (grams/100ml of ) 20.0 @ 25 degC

Ether: (grams/100ml of ) 26.3
Benzene: Soluble
Chloroform: Soluble

HCL Salt

Melting point 197 degC

Water: (grams/100ml of ) 250 @ 25 degC

Alcohol: (grams/100ml of ) 34.4 @ 25 degC

Ether: insoluble

Chloroform: (grams/100ml of ) 8.0

Glycerine: Soluble
Click to expand...



To address the question of what to do about getting other "caines" out of coke, the first thing that needs to be done is to look at the physical properties of the substances which then allows a strategy of separation to be developed.

Without equipment and chems, the best tools to work with are solvent solubilities at different temperatures and the variations between suspected and known contents of the mixture.

Some very quick data on Novacaine from CRC

Procaine HCl (Novocaine) (Mole Weight 272.77g) [sorry can't find FB info]


Melting point 156 degC

Water: (grams/100ml of ) 166.0 @ 25 degC

Alcohol: (grams/100ml of ) 3.3 @ 25 degC

Ether: Very Slightly Soluble

Chloroform: Soluble[/QUOTE]


After all those figures, lets look at what this tells you with a suspected mixture of Novocaine and cocaine, both as HCl salts. We can first see there is quite a difference in melting points, but to attempt to separate by melting one and pouring off would result in loosing a significant portion of the desirable That is because a mixture will result in an overall melting point of both substances. Another difference is that the solubility in alcohol is greatest for coke HCl, almost 10:1 in favour at 25 degC. So attempting to separate these adequately may begin by:

a) Choosing the most suitable alcohol. Solubilities will vary with methanol, ethanol, propanol etc.
b) Estimating, or looking up variations in solubilities over wide temperature ranges

A third option requiring a greater degree of knowledge in solubilities, disassociation etc is to use a mixed solvent, where one solvent is more hydrophobic or hydrophillic. Knowing the pKa one can then change pH, or add other things (buffers) and effectively alter the solubility of one or both compounds.

Getting back to the mixture above, I would choose MeOH for this one, as (hunch) Novacaine may be more soluble in longer chain alcohols [Biscuit or BT comment here??] Cooling the alcohol down should lower the solubility of both, but also hopefully widen the gap between the compounds. Using appropriately large amounts of solvent should help minimise losses of the coke, but it will happen - some is always lost. But good technique can make quite a difference. You then extract the highly dilute coke FB /alcohol soln. with ether or Zippo

Another method, is elution chromatography. It is simple and chemicals are generally easily available (although expensive for pure). It usually separates such differently sized molecules quite adequately by employing the principle that different things travel at different rates through a certain medium in a certain solution.


As BT said, basing usually requires quite a bit of coke. Doing multi step cleaning loses more product each time. Just transferring contents will lose a bit, so these procedures aren't probably economical to do unless you want to prepare as pure as sample as possible to use as a close to pure reference. You may end up with 25% or less from 50% pure coke, but if done correctly it can be used to check other coke (using the thiocyanate reaction colour change) or by using thin layer chromatography


Here's two excellent databases on physical properties of
solvents and chemicals

By the way, I don't encourage people to use Coke. The chemistry outlined here hopefully demonstrates the potential for coke to be cut and will enlighten "would be hollywoods" on their anxious pursuit. Personally, although tasty, I feel it is potentially the most insidious inducer of psychosis. Apart from the very rare offer of a line, these days I have no interest in coke at all. I could write a book on the lives i've known to have been adversely changed by it - including my own.

My advice if you are tempted towards the mystique surrounding coke is to keep it as a tasty delicacy - just for occasion. That way it will remain good for many things, and bad for relatively few :)



Edit: Removed irrelevant details on benzocaine
 
Last edited:
in an ideal world, if you wanted coke, you'd simply go to Bolivia! of course you'd come back tanned, with no septum, but hey, you wanted coke right? ;)
 
You must log in or register to reply here.
Top