| ▲ | refulgentis 7 hours ago | ||||||||||||||||||||||||||||||||||
Not OP, but: > "You found a paper" johnbarron didn't find it. The authors cited it as foundational to their own work. it's ref. 38 in the paper under discussion. From the paper: "this finding had not been reported in the MP literature until 2020, when Witzig et al. reported that laboratory gloves submerged in water leached residues that were misidentified as polyethylene."[1] > "most of these plastic studies are [not] doing the necessary controls" which studies? The paper they linked surveys 26 QA/QC review articles[1]. Seems well understood. > "a laboratory setting where nanomolar detection levels are used to make broad claims" This is like saying "miles per gallon" when discussing weight. "nanomolar detection levels"...microplastics are individual particles identified by spectroscopy, reported as particles per mm^2. "Nanomolar" is a dissolved-species concentration unit. It has nothing to do with particle counting. (I, and other laymen, understand what you mean but you go on later in the thread to justify your unsourced and unjustified claims here via your subject-matter expertise.) > "(almost impossible) task of preventing the contamination" The paper provides open-access spectral libraries and conformal prediction workflows to identify and subtract stearate false positives from existing datasets[1]. Prevention isn't the strategy. Correction is. That's the entire point of the paper they linked and the follow-up in [2] [1] https://pubs.rsc.org/en/content/articlehtml/2026/ay/d5ay0180... [2] https://news.umich.edu/nitrile-and-latex-gloves-may-cause-ov... | |||||||||||||||||||||||||||||||||||
| ▲ | timr 6 hours ago | parent [-] | ||||||||||||||||||||||||||||||||||
> This is like saying "miles per gallon" when discussing weight. "nanomolar detection levels"...microplastics are individual particles identified by spectroscopy, reported as particles per mm^2. "Nanomolar" is a dissolved-species concentration unit. It has nothing to do with particle counting. (I, and other laymen, understand what you mean but you go on later in the thread to justify your unsourced and unjustified claims here via your subject-matter expertise.) This paper used “light-based spectroscopy” [1]. Many others use methods that depend on gas chromatography or NMR. A relatively infamous recent example used pyrolysis GCMS to make low-concentration measurements (hence: nanomolar), which they credulously scaled up by some huge factor, and then made idiotic claims about plastic spoons in brains. Relatively little quantitative science in this area depends on counting plastic particles in microscopic images, but it’s what gets headlines, because laypeople understand pictures. [1] as an aside, the choice of terminology here is noteworthy. A simple visual light absorption spectra is also “light based spectroscopy”, but is measuring the aggregate response of a sample of a heterogeneous mixture, and is conventionally converted to molar equivalents via some sort of calibration curve (otherwise you can’t conclude anything). But there could be other approaches that are closer to microscopy, which they also discuss. “Particles per square millimeter” is also a unit of concentration (albeit a shitty one, unless your particles are of uniform mass). Anyway, the point is that these kinds of quantitative analyses are all trying to do measurements that are fundamentally about concentration, which is why I chose the words that I did. | |||||||||||||||||||||||||||||||||||
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