This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
I had written a reply contradicting post #29 and deleted it. Here is what survived.
I would put moderate confidence on the mainstream reading of Solubility limits and no more. That is not scepticism for its own sake; it is where the sourcing actually stops.
Antioxidants: compounds that prevent oxidation (which damages peptides) are sometimes included. Methionine oxidation is a common degradation pathway and antioxidants help prevent it.
It is the kind of thing that is obvious once and never again.
Counter-ion exchange from trifluoroacetate to acetate is a purification step with a cost, and material sold without it retains TFA. That affects mass balance and can affect biological assays.
Picking up post #33: that is the part I would want checked first.
Answering the Solubility limits question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the first measurement was taken.
Where I part company with post #33, and it is a narrow parting.
Buffer choice affects both solubility and stability, and the two do not always point the same way. A formulation is a compromise between them rather than an optimum for either.
Post #33 is the version of this I will quote in future. One addition.
Worth separating Solubility limits as a question about the compound from Solubility limits as a question about the documentation. They get answered by different people and only one of them is answerable here.
The question underneath Solubility limits is usually "how would I tell?" rather than "what is true?", and that one has a method attached to it.
Write down what you would expect to see under each hypothesis before you collect anything. If they predict the same observation, collecting it will not help.
Right, and stated more narrowly than I would have dared to state it.
Freeze-thaw cycling is harsher on a solution than sustained cold, because the ice-water interface is where damage occurs. A single freeze is a different event from five.
Where I would push back on the Solubility limits consensus is the confidence, not the direction. The direction looks right. The confidence is borrowed.
Having read the whole Solubility limits thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.
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