Joe,
Unfortunately there are no references for these things because this is basic chemistry knowledge. Trust me, it is VERY BASIC chemistry. You can do the math yourself even if the last chemistry you did was in high school.
Allow me to correct your understanding here... i'll give you a small chemistry lesson and even take the time here to photoshop pictures of chemical structures for you so that you may understand better. I'm also going to copy and paste direct from my chemistry notes from school, since I have all the descriptions right here of what an ester bond is and how it is formed. Testosterone is not an independant ingredient when it is colloquially known as 'testosterone enanthate', or 'testosterone propionate'. Now the lesson shall begin:
Here is your basic bare-bones testosterone molecule:
<img src="http://forums.steroid.com/attachment.php?attachmentid=124978"/>
What you have here is testosterone without an ester bonded to the molecule. Lets focus on testosterone propionate here in order to put this in perspective for you. Testosterone itself is a lipid (a fat), as it is cholesterol based. Its sterane structure makes it a fat (all steroid hormones are really fats), and this is why anabolic steroids work in the manner they do, by diffusing through the phospholipid bilayer membrane of the target cells. They are fat-soluble, so they can do this with ease. In comparison, protein hormones cannot do this as they are proteins, and not fats. Protein is not fat-soluble.
Now, here's a little refresher on lipids in general for you, copypasted straight from my chem notes:
Fats and oils are made by attaching fatty acids to a glycerol molecule. The glycerol molecule - see page 16 in written notes. Glycerol molecules can react with the carboxylic acid part of up to 3 fatty acids producing up to 3 water molecules and either a fat or an oil molecule - see page 16 in written notes and page 52 in textbook. The resulting fat or oil molecule is called a triglyceride. Whether the fat or oil is solid or liquid in room temperature depends on whether or not the fatty acids in the triglyceride are polyunsaturated or a saturated. If the fatty acids are saturated, then it's most likely a solid. If they are polyunsaturated, then it's most likely a liquid. The shorter the chain lengths, the less the attraction between molecules, so therefore the smaller the chain then the more likely it's an oil and the larger the chain, the more likely it's a fat.
<img src="http://forums.steroid.com/attachment.php?attachmentid=124982"/> <img src="http://forums.steroid.com/attachment.php?attachmentid=124983"/>
Alright, that's the basic low-down on fats. Now, here is where the ester bonding comes into play. Again, more from my chem notes:
Whenever an alcohol-containing molecule reacts with a carboxylic acid-containing molecule such as a fatty acid reacting with glycerol, water molecules (H2O) are always produced and the bond between the newly united molecules is called an ester linkage (or, ester bond) and the process is called esterification (see page 40 in Arms & Camp textbook). The result is a molecule called a triglyceride.
Diagram of the esterification process:
<img src="http://forums.steroid.com/attachment.php?attachmentid=124984"/>
(3) Phospholipids
Phospholipids are similar to triglycerides in that fatty acids are esterifying but the difference is that one of the alcohol groups is esterifying to a phosphate group (see page 40 in Arms & Camp textbook.)
<img src="http://forums.steroid.com/attachment.php?attachmentid=124985"/>
Alright, thats the basics on ester bonding. Now, back to testosterone propionate.... i've already posted a picture of the chemical strucutre of bare bones testosterone with no ester attached to it. Now, allow me to introduce you to our friend here, called Propionic Acid:
<img src="http://forums.steroid.com/attachment.php?attachmentid=124990"/>
As you can see, its a very small molecule. I will now explain where the typical bonding area is when it esterifies (bonds) to other molecules (in this case, testosterone). So, what happens in a lab is a chemical reaction is produced whereby the propionic acid loses its OH group, and an H comes off the testosterone. The OH from the propionic acid, and the H from the testosterone bond to form H2O, and leave the molecule as such. Now, you have a newly formed chemical compound: TESTOSTERONE PROPIONATE.
Scroll up and take a look at the bare-bones testosterone picture. Now compare it with this, testosterone propionate:
Here, in case you haven't noticed, I took the liberty of outlining the area on the molecule that has now changed (or rather, an addition):
See where the OH is gone from the Propionic Acid? And how it is now bonded to testosterone? Once again, this forms Testosterone Propionate. It is no longer testosterone - peroid.
Here is a further 3D-ish picture of a Testosterone Propionate molecule I built out of my organic chemistry set (I originally posted this in a thread from a loooong time ago, here:
http://forums.steroid.com/showthread...ight=chemistry )
Bare-bones testosterone:
Testosterone Propionate:
See the prop attached to it?
What this esterification process does is enable the main compound (testosterone) to be released at slower rates in the body than if testosterone was un-estered to anything. Your body now has to send the anabolic steroid to the liver and use enzymes to cleave off that ester so that testosterone is in its bare-bones form again (which is the only form it can actually do its job and be used by the body). This is also THE reason why there is no such thing as site-specific growth except for AAS like testosterone suspension. Test suspension is simply un-esterified testosterone suspended in water. All esterified anabolic steroids must be processed by enzymes before they can be in their useable form. The longer the bigger the ester is, the longer it takes the body to cleave the ester off (hence the longer release times for esters like enanthate, undecanoate, etc.)
Alright, so the chemistry lesson is over. What does all this mean and how does it refer to the mg/ml stuff I was talking about earlier? Well, it's pretty simple at this point in case you haven't figured it out... the propionic acid has a particular molecular weight to it.... and testosterone has a particular molecular weight..
So at this point, its basic grade 2 math. You take the molecular weight of propionic acid and use this nifty little function on your calculator: + and punch in the molecular weight of bare-bones testosterone. Now you have the molecular weight of testosterone propionate. Now, it stands to reason that if you have a longer heavier ester attached to testosterone, your weight measurements of pure testosterone will become fudged because you now need to factor in the weight of the ester, because remember: testosterone is no longer testosterone when you have enanthate attached. It is now testosterone enanthate.
I hope you understand now and I hope this helped you!