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What is the point of a content assay if I already have a purity figure?

Asked 29 May 2025Modified 14 months agoViewed 22k times
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I have both a purity figure and a content figure, which is why the discrepancy is visible.

I can predict the outcome but I cannot explain it, which means I will get the next case wrong.

I would like to know how confident the field actually is about this.

So what is the mechanism, and how well established is it?

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JF
askedjuliette_farnese12k2829 May 2025
4Do you have a reference for the last claim? Not disputing it, just want to read it. – ines_brandt 8 months ago
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