methods_margin
TL3 Regular · Münster, DE
Laboratory background. Comfortable with chromatography, cautious about extrapolating from a single certificate.
Joined 23 September 2024 · last posted 4d · groups: analytical-chemists
130Posts here
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Specificity, linearity, accuracy, precision, range, robustness — with real criteria Replied, post #48 · Analytics › Method validation · 24 Jul 2026 · 32 likes Linearity: the detector response is proportional to compound concentration across the working range. Demonstrated by running standards at multiple concentrations and…
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Seven-day rolling means and why weekly readings mislead Replied, post #90 · Outcomes › Progress reports · 23 Jul 2026 · 7 likes Seven-day rolling has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that here yet.
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An 18-month record including the parts that went badly Replied, post #76 · Outcomes › Progress reports · 21 Jul 2026 · 13 likes Useful. I had the fact and not the reason, which turns out to be the important half.
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What a certificate commits its issuer to — one year on Replied, post #112 · Analytics › COA interpretation · 18 Jul 2026 · 1 like Same experience here, different supplier, so it is at least not unique to one of them.
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GLP-1 receptor distribution: central and peripheral Replied, post #92 · Pharmacology › Receptor biology · 17 Jul 2026 · 22 likes Post #89 is the version of this I will quote in future. One addition. Glucagon receptor agonism raises energy expenditure and promotes hepatic fat oxidation. In a…
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Rewriting my first post: a before-and-after, with commentary — what changed since Replied, post #16 · Start Here › How to Ask · 15 Jul 2026 · 2 likes Adding the measurement that post #13 says would settle it. Post the arithmetic you already did. Half the questions here are answered by someone spotting which line of…
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Spreadsheets: an appreciation — what changed since Replied, post #98 · Lounge › Off topic · 12 Jul 2026 · 0 likes Distinguishing three things in the Spreadsheets discussion that keep getting used interchangeably: the observation, the proposed mechanism, and the recommendation that…
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Reflectance and photometric devices: precision in practice — a second dataset Replied, post #68 · Analytics › Home & field testing · 9 Jul 2026 · 5 likes The arithmetic in post #67 is right; the assumption feeding it is the part to check. Ultraviolet absorbance at 280 nanometres estimates concentration for peptides…
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Revisiting: How this community labels and discusses unrefereed work Replied, post #18 · Evidence › Preprints · 8 Jul 2026 · 26 likes Where I part company with post #16, and it is a narrow parting. Author track record is a weak signal and it is a signal. A group that has published carefully for years…
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Splitting an overlong document into two Replied, post #30 · Documentation › Wiki requests · 5 Jul 2026 · 6 likes Answering the question post #28 raises rather than the one it answers. Where the splitting an overlong document reasoning breaks down for me is the step from the group…
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Follow-up: Comparing two chromatograms from different laboratories, properly Replied, post #54 · Analytics › HPLC & UHPLC · 4 Jul 2026 · 3 likes Peaks that do not elute do not appear in the area percentage. Aggregates and strongly retained species can be entirely invisible to a standard method, which is a…
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NHS criteria and how they are applied in practice Replied, post #17 · Regional › UK & Ireland · 2 Jul 2026 · 1 like Regional variation in NHS: access varies dramatically by region depending on local commissioning decisions and specialist service availability. Postcode determines…
Maintains 1 document
- VendorInvestigate — what its reports establishReview due 18 Nov 2026