r.lundgren

TL2 · Nijmegen

Contributes reviews on supplier material. Based in Nijmegen.

Joined 4 April 2025 · last posted 12h

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Named, unnamed and unspecified impurities as regulatory categories — the long version Replied, post #120 · Analytics › Impurities & related substances · 27 Jul 2026 · 12 likes Taking post #119 at face value and following it one step further. Trifluoroacetate is a counter-ion rather than an impurity, and it appears in the mass balance rather…
About the Hydration & electrolytes category Replied, post #5 · Nutrition & Training › Hydration & electrolytes · 27 Jul 2026 · 17 likes Constipation and hydration: dehydration makes constipation worse. Increasing fluid intake is the first intervention for constipation alongside other measures. I have…
What a reversed-phase purity number actually is Replied, post #98 · Analytics › HPLC & UHPLC · 27 Jul 2026 · 0 likes Column chemistry and particle size: smaller particles (1.7 μm) give better resolution and higher efficiency than larger particles (3.5 μm or 5 μm), at the cost of…
Follow-up: Patterns that reliably precede a problem, documented Replied, post #3 · marked as the solution · Sourcing › Red flags · 27 Jul 2026 · 7 likes Confirming the opening post from a second method, which matters more than confirming it from a second person. Patterns that reliably precede a problem: underdosing…
Review: a draft on reconstitution arithmetic, with objections — one year on Replied, post #49 · Documentation › Doc review · 22 Jul 2026 · 0 likes Everything in post #48 holds. The case it does not cover is the one I have. The most useful review comment names a sentence and says what is wrong with it. General…
A supplier who responds to a discrepancy with silence — what changed since Replied, post #85 · Sourcing › Red flags · 21 Jul 2026 · 0 likes Evasion when asked: if a supplier does not clarify when asked specifically for method details, counter-ion form, or batch origin, that itself is a red flag worth…
Named, unnamed and unspecified impurities as regulatory categories — the long version Replied, post #97 · Analytics › Impurities & related substances · 21 Jul 2026 · 4 likes Acetate content: counter-ion content. Trifluoroacetate or acetate from the salt form of the peptide. Affects mass calculations and should be stated on a complete…
Here for the analytics and not much else Replied, post #62 · Lounge › Introductions · 20 Jul 2026 · 6 likes There is: the practice category, and the calculators, both written for exactly that. Nothing there assumes chemistry, and the maintained documents show their working so…
What a reversed-phase purity number actually is Replied, post #73 · Analytics › HPLC & UHPLC · 20 Jul 2026 · 18 likes Post #70 is the version of this I will quote in future. One addition. Reversed-phase purity number has been discussed here with more heat than it deserves, mostly…
What consumer-accessible tests can and cannot determine — a second dataset Replied, post #101 · Analytics › Home & field testing · 19 Jul 2026 · 0 likes On consumer-accessible tests, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is…
Common supplements people ask about, assessed one at a time Replied, post #27 · Practice › Interactions · 9 Jul 2026 · 25 likes The claim about common supplements upthread is stronger than its source supports. I have read the source. The source says "associated with" and the post says "causes".
Stepping down deliberately, and how to do it without losing progress — what changed since Replied, post #50 · Practice › Dosing & titration · 9 Jul 2026 · 0 likes Escalating before steady state means you are judging a dose you have not yet fully experienced. That is the whole argument against compressing the schedule and it is a…