Direct multielement determination of human hair by induction-heating electrothermal vaporization with ICP-MS
Bibliographic record
Abstract
Conventional methods of hair analysis using instruments, such as inductively coupled plasma-mass spectrometry (ICP-MS), typically require a digestion step that has many disadvantages. As an alternative, we report on the application of an induction heating-electrothermal vaporizer (IH-ETV) with ICP-MS detection for direct multielement determination of sub-milligram amounts of solid hair material. As, Cd, Cu, Hg, Pb and Zn were determined using powdered hair standard reference materials (SRMs) with IH-ETV-ICP-MS. Transient profiles reveal that powdered hair SRMs and hair strands have the same analyte signal shapes, while solutions have different shapes. External standards calibration using SRMs gives results that agree with the certified values, with the precision of determination ranging from 9–54%. Absolute detection limits ranged from 0.01–8 ng. These values are sufficiently low that they should allow the determination of metals at natural levels in a single human hair strand.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".