An ICP-AES method after nitric, hydrochloric, and hydrofluoric acid digestion was applied to five coded commercial sunscreens. Titanium, reported as the element, reached 8.13 × 10^3 and 18.5 × 10^3 μg/g in two products that listed titanium dioxide and was below 0.2 μg/g in two others. Lead was below the 3.2 μg/g detection limit in all five. Chromium, copper, manganese, iron, zinc, aluminium, magnesium, and boron varied widely among the codes, including high iron, zinc, copper, manganese, and chromium in code IS. Emulsion slurry introduction was tried and abandoned because the plasma was unstable. Product names are not printed; only laboratory codes are used.
Key numbers
| Analyte | Matrix | Value | Unit | Statistic | N | Where |
|---|---|---|---|---|---|---|
| Ti | sunscreen cream, ICP-AES, 100 mg sample | 0.2 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Al | sunscreen cream, ICP-AES, 100 mg sample | 0.4 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Zn | sunscreen cream, ICP-AES, 100 mg sample | 0.2 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Mg | sunscreen cream, ICP-AES, 100 mg sample | 0.5 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Fe | sunscreen cream, ICP-AES, 100 mg sample | 0.5 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Cu | sunscreen cream, ICP-AES, 100 mg sample | 0.9 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Mn | sunscreen cream, ICP-AES, 100 mg sample | 0.2 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Cr | sunscreen cream, ICP-AES, 100 mg sample | 0.6 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Pb | sunscreen cream, ICP-AES, 100 mg sample | 3.2 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| B | sunscreen cream, ICP-AES, 100 mg sample | 0.8 | μg/g | lod | Table 5 p.PDF p.5 (printed 346) | |
| Ti | sunscreen code NA, SPF 15, ICP-AES | 8.13 × 10^3 | μg/g | mean | 3 | Table 6 p.PDF p.6 (printed 347) |
| Ti | sunscreen code CT, SPF 30, ICP-AES | 18.5 × 10^3 | μg/g | mean | 3 | Table 6 p.PDF p.6 (printed 347) |
Methods (brief)
About 100-150 mg in PTFE, heated to 125-130 °C for 2 h in a steel bomb, diluted with 0.5 M HNO3. RF power 1500 W, nebulizer 0.8 L/min, axial view. Recoveries from spikes (n=5) were 95.0% Ti, 98.2% Zn, and 101.3% Fe, with the full set in Table 5. RSD at 250 μg/L was 2.2-8.1%.
Detection and reporting: Table 5 LODs (μg/g, 100 mg sample, 3s): Ti 0.2, Al 0.4, Zn 0.2, Mg 0.5, Fe 0.5, Cu 0.9, Mn 0.2, Cr 0.6, Pb 3.2, B 0.8. LOQ described as nearly three-fold the LOD, without a second numeric column.
Basis: Total element in the cream or lotion as sold, μg/g, after acid digestion. Not a migration or sweat-extraction test. Titanium is measured as Ti (labels list titanium dioxide). Chromium is total Cr, not chromium(VI).
Evidence fitness
This source can support: Total Ti, Al, Zn, Mg, Fe, Cu, Mn, Cr, Pb, and B in five coded sunscreens after total digestion; Method LODs and spike recoveries.
It cannot support: Dermal migration or bioaccessible fraction; Chromium(VI); Brand-named concentrations; A certification limit.
Limitations
Only five of nine collected products are in Table 6. Slurry results were not quantitative and are not entered. No regulatory numeric limit for these analytes in sunscreen is stated as a measured comparison value, so no regulatory_limit rows were added. Chromium and arsenic species were not determined; arsenic was not in the analyte list. Codes may abbreviate brands but are not expanded here.
Related evidence
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