Raman imaging of particles released from nonwoven PET, nonwoven PP, and woven nylon filter bags and their strings.
Source details
Tingna Mei, Jiahua Wang, Xiaofeng Xiao, Jingwen Lv, Qiaocong Li, Huang Dai, Xiaodan Liu, Fuwei Pi. Foods. 2022.
Findings
Chemical imaging identified PET, PP, nylon, and PE in soaking samples. Multichannel spectral fitting found additional particles missed by a single-peak imaging approach. Surface-attached fragments and string material contributed to the observed findings.
Scroll horizontally for methods and measurement limits.
| Reported result | Conditions | Size context | Original locator |
|---|---|---|---|
| 34 of 36 soaking samples contained Raman-identified polymers | Nonwoven PET, nonwoven PP, woven nylon bags in 30 mL ultrapure water; 70, 80, 90 °C; 1, 5, 10, 30 min; selected Raman regions | Raman mapping regions; 3 µm scanning step; no complete validated lower-size count boundary | PDF p. 9 §3.4 and p. 10 Table 1; p. 2 §2.1 |
Methods and scope
Separate method-optimization and detection experiments. The detection experiment soaked individual filter bags in ultrapure water over stated temperatures and times; glass microfiber filtration and selected-region Raman imaging followed. Direct classical least squares used reference spectra to distinguish overlapping polymer signals. Cleaned samplers, covered glass dishes, and powder-free gloves were reported. A numerical full-procedure blank series is not reported in the main article.
What this source can support
Direct evidence of chemically identified polymer release and method-dependent detection, without extrapolating observed-region counts to all consumer bags.
Selected regions were imaged; not a complete filter census. Main-text count examples belong to imaging comparisons, not particles per retail cup. Some detected material can come from strings and particles already attached to bag surfaces. No standardized lower-size quantitation validation or human-health endpoint. PDF text layer contains extensive duplicated text; cited pages were visually checked.
Related evidence
Reported values and source locations
| Reported value | Measurement basis | Conditions and size context | Original document location |
|---|---|---|---|
| 34 of 36 soaking samples contained Raman-identified polymers | Detection frequency across study conditions, not product-market prevalence | Nonwoven PET, nonwoven PP, woven nylon bags in 30 mL ultrapure water; 70, 80, 90 °C; 1, 5, 10, 30 min; selected Raman regions Raman mapping regions; 3 µm scanning step; no complete validated lower-size count boundary | PDF p. 9 §3.4 and p. 10 Table 1; p. 2 §2.1 |
Source provenance
Primary PDF SHA-256: 344cfd824c7ee6c0cc5f35b6b33c66dae98b6a6be81750b3d207b73c4ea90954
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