Acids and Salts

[ergoamide]

Here's some info on acids if you make your alkaloids into salt to help storage.

M - Molecular Weight

Hydrochloric Acid HCl - M 36.5

Acetic Acid(vinegar) C2H4O2 - M 60 (1.6 x HCl)

Sulphuric Acid H2SO4 - M 98 (2.5 x HCl)

Tartaric Acid C4H4O6 - M 148 (4 x HCl)

Citric Acid C6H8O7 - M 192 (5.2 x HCl)

When converting alkaloids to salts it is easier to handle and wiegh for accurate dosage and measurments if you have more. The acid with the higher molecular formula will form more salt than an acid with a lower formula hence the reason that it is easier to handle a tartrate to a hydrochloride.

In the case of changing alkloids to salts excess acid can sometimes be left behind after evaporation this can be removed but it can be a nusance. That's why it is more user friendly to use acid that are safe for consumption such as Acetic, Tartaric or Citric. A common acid used in pharmacy is Tartaric due to it's larger Mf making it easier to weigh(A Tartrate would yield roughly 4 x that of HCl salt). Citric acid is generally not used as while it is 'larger' than Tartaric it is considered excess for the point of wieghing. Sulphuric and Hydrocholric acid are also fequently used but for the sake of the home chemist Sulphuric is very corrosive and not safe for consumption so any excess acid left after making salts can be harmful, this is also the case with Hydrocholric however to a much lesser extent that it is nearly irrelevant. The main reason hydrochloric is not as good is because fo it's low Mf maing wieghing and handling of the salt harder.

Tartaric, Citric and Acetic acid can all be bought at supermarkets in their crystal form in small jars.

Hydrochloric and Sulphuric can be bought from most big hardware store chains as a floor cleaner(It comes very concentrated). Keep in mind though these chemicals are very dangerous when concentrated.

I hope this helps any young budding chemists in their home labs.

If you disagree with anything I've said please feel free to point it out as I am not an authority on this subject.

[dracos6]

cheers ergo,

that is a usefull bit of info, maybe i'll stop using hydrochloride as my last a/b ended up with diddly squat and its quite possible (actually most likely) that this was due to the small concentration of alkaloids in the material.

more would def have been better, as i could then have been closer to ruling out a mistake on my part (cant think of any) or inactive plant material (seriously doubt it).

citric would also be quite good if you only had a small amount of material and wasnt sure of alkaloid content

thanks muchly

[ergoamide]

Drasco i found otu shortly after i posted this some other fact about acids. Certain acids are diprotic and triprotic meaning they bond to 2 or 3 alkaloids respectively.

Citric acid is triprotic so while it may have a much larger mass than hydrochloric it will not form too much more than a hyrdochloride as it bonds to 3 alkaloids. The most comonly used acids are tartaric, sulphuric and hydrochloric. Tartrates are generally the larger compound after making the salt as compared to sulphates and hydrochlorides.

Sulphuric acid is diprotic so bonds to 2 alkaloids but it still leaves more than a hydrochloride which is why it is the main acid used for mescaline.

Also another factor in choosing your acid, if you intend to use the salt form make sure you cna find dosages using that salt as not all salt doseages will be the same. 300mg of a sulphate wont be the same as 300mg of a tartrate.

Also excess hydrochloric or sulphuric acid can be evaporated off in the oven at a temp of about 100 so as not to ruin your salts.

As always some acids are very caustic so just dont be silly and spill it on your self.

On a different note i wonder if anyone has ever used hyrdoflouric acid hehe like to see that one.

[dracos6]

cheers ergo, gonna have to go find some tartaric acid

[cookie-monster]

ergoamide:

Certain acids are diprotic and triprotic meaning they bond to 2 or 3 alkaloids respectively.

Citric acid is triprotic so while it may have a much larger mass than hydrochloric it will not form too much more than a hyrdochloride as it bonds to 3 alkaloids. The most comonly used acids are tartaric, sulphuric and hydrochloric. Tartrates are generally the larger compound after making the salt as compared to sulphates and hydrochlorides.

Sulphuric acid is diprotic so bonds to 2 alkaloids  but it still leaves more than a hydrochloride which is why it is the main acid used for mescaline.

Also excess hydrochloric or sulphuric acid can be evaporated off in the oven at a temp of about 100 so as not to ruin your salts.

As always some acids are very caustic so just dont be silly and spill it on your self.

OMG this info is so wrong that I have to speak up.

How protic an acid is refers to the number of acidic protons it has. Sulphuric acid has 2. They are the 2 Hs in H2SO4. It will form a salt by binding to each amine group within your alkaloid, once. The salt will be designated as (alkaloid.HSO4) not a salt of ((alkaloid)2.SO4). It takes a much more powerful reagent than an amine to displace the 2nd acidic group from a diprotic acid. If your alkaloid has more than one amino group the acid will bind with each.

Sulphuric acid is also very destructive to complex organic molecules, reducing them to elemental carbon (tar).

Simple orgainics like speed and ecstasy are made into hydrochloride and sulphate salts but complex organic molecules are generally converted to tartrates and citrates due to their ease of purification and lack of destruction of the parent chemical. An additional problem is that strong mineral acids also form complexes with the waters of hydration that the salt has. This bound acid and water will require a temperature of around 300 C to drive it off. This temp is totally incompatible with the salt resulting in reduction to elemental carbon (tar).

A caustic acid is the best example of an oxymoron that I've seen in years!

In summary simple alkaloids such as ephedra can be converted to salts of mineral acids but more complex orgainic chemicals such as LSAs have to be made into organic acid salts.

[teonanacatl]

ok so now im confused cos im the one that wrote that info that ergoamide got his info from . im fully aware what protic means, you say it takes a much more powerful reagent then an amine to displace the second H+ from a diprotic acid, then y does it dissociate in water to give 2 H+???? the H+ protonate the alkaloid and the conjugate base of the acid is drawn to the + charge through electrostatic interaction. now im not saying your wrong but as far i know to my knowledge (not the be all and end all by any means)what i wrote is correct. what i wrote about alkaloids and polyprotic acids bonding together i did not learn at uni but came across it said at the nook by a person who seems to know his stuff. also im not sure what u are implying about using caustic to describe an acid, i wouldnt use it but caustic just means, somthing capable of burning, corroding, dissolving, or eating away by chemical action, and acids do that.

this is my reply to ergo's post on another forum, please tell me if you think its wrong and i am happy to believe you.

 

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When converting alkaloids to salts it is easier to handle and wiegh for accurate dosage and measurments if you have more. The acid with the higher molecular formula will form more salt than an acid with a lower formula hence the reason that it is easier to handle a tartrate to a hydrochloride.

 

yes thats true but its still going to be measured in grams or miligrams as long as you have some digiscales it doest matter. if your lookin to buy digiscales check out ebay they got good prices.

 

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Tartaric, Citric and Acetic acid can all be bought at supermarkets in their crystal form in small jars.

 

Hydrochloric and Sulphuric can be bought from most big hardware store chains as a floor cleaner( It comes very concentrated ). Keep in mind though these chemicals are very dangerous when concentrated.

 

any thing that you buy in crystal form is likely to become crystal form again apon evaporation, there will be excess acid so you must weigh the amount you use and subtract that from the amount you get, that will give you the freebase weight. this is not complicated but is probably to complicated for a newbie. also some acids are polyprotic. eg citric acid is triprotic, H2SO4 is diprotic. diprotic means that when they dissociate they give up 2 H+ which means when salting they will bind to 2 molecules of alkaloid, triprotic means three. this can complicate weighing.

 

The reason for using HCl is because its easy to evaporate all off. the crystals optained should be ground and placed in the oven on a low temp to drive off any HCl that was in the crystals. H2SO4 is corrosive but once again it is driven off apon evaporation. the good thing about mescaline sulphate is it recrystalises easy giving purer crystals. another thing to consider about choosing the acid is if your a newbie its best to pick an acid where there is dosage info about it becuase 4 grams of citrate wont be the same as 4 g of sulphate, its not hard to work out but maybe confusing for a newbie. one final thing about choosing an acid is pick one that has documented use, y? because certian salts have different properties, im pretty sure mescaline tartrate is very hydroscopic which can cause problems for handleing and if washing with acetone to clean it.

 

on a side note i wouldnt think HCl was that bad for you, your stomach is made up of it, providing you didnt drink concentrated acid. ive tasted it before as im sure many others have, its just sour.

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[cookie-monster]

No it doesn't disociate in water to give 2 H+. In water it reacts as :

H20 + H2SO4 = H3O+ + HSO4-

If you keep titrating with a strong base you will lead to:

H3O+ + HSO4- + 2OH- = SO4-- and 2H2O.

The first proton disociates at the pH of the pKa1 value and the second proton at the pH of pKa2. It will take a strong alkali metal base like sodium hydroxide to get that 2nd proton free.

The old system of rating acids by normality rather than molarity is the source of this confusion. Under this old system 1 molar sulphuric acid was classified as 2N, because it had 2 protons to give. But the second proton is not as reactive and takes a strong base to dislodge it. In a typical chem lab lesson they will have you titrate the acid with base and under these conditions you will remove the second proton. But if you are adjusting the pH of water or forming amine salts you will only be dealing with the first proton.

I too like HCl for its relative ease of evaporation but regardless of what you use it really is important to titrate the added acid as the need to evaporate excess can lead to substantial degredation of the more delicate organic molecules. It really is a matter of doing the homework on your desired extract to see what is suitable.

[teonanacatl]

ah yep makes sense, though once it looses its 2 H+ it has more resonance structures therefore its more stable so wouldnt this be thermodynamically prefered???