Micro-Raman analysis of visually isolated particles above a coarse filtration threshold in retail salts.
Source details
Ali Karami, Abolfazl Golieskardi, Cheng Keong Choo, Vincent Larat, Tamara S. Galloway, Babak Salamatinia. Scientific Reports. 2017.
Findings
Only part of the visually selected particles were confirmed plastic polymers. Polypropylene and polyethylene were common; pigments, amorphous carbon, and unresolved spectra were recorded separately. A lake-salt sample blocked the filter and was excluded.
Scroll horizontally for methods and measurement limits.
| Reported result | Conditions | Size context | Original locator |
|---|---|---|---|
| 30 of 72 selected particles were confirmed plastic polymers | Salt packages dissolved, coarse-filtered, density-separated, visually screened, then each selected particle analyzed by micro-Raman | Extraction >149 µm; selected particles observed 160-980 µm | PDF p. 2 Results |
Methods and scope
Whole packages dissolved and filtered through a coarse membrane, followed by sodium-iodide density separation and visual selection. All selected particles received micro-Raman analysis. Covered glassware, cleaned equipment, filtered reagents, biosafety-cabinet processing, and procedural water/NaI blanks were used; the inspected text does not provide a complete numeric blank-count distribution.
What this source can support
Direct salt occurrence evidence with particle chemistry. Especially useful for showing why visual particle counts are not equivalent to confirmed microplastics.
Excludes particles smaller than the filtration threshold and may miss visually unselected particles. An excluded sample is not a nondetect. Unknown spectra remain unknown, not zero plastic. The authors’ health reassurance is not adopted because this study did not measure human health outcomes. Figure 3 panels were corrected separately.
Related evidence
Reported values and source locations
| Reported value | Measurement basis | Conditions and size context | Original document location |
|---|---|---|---|
| 30 of 72 selected particles were confirmed plastic polymers | Number across selected salt samples; not all-particle capture or universal confirmation fraction | Salt packages dissolved, coarse-filtered, density-separated, visually screened, then each selected particle analyzed by micro-Raman Extraction >149 µm; selected particles observed 160-980 µm | PDF p. 2 Results |
Source provenance
Primary PDF SHA-256: d5adaa4c2600cdf37747bcb8a956f08ca847bcd63c017e6bfb97a71977eb259c
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