Second-Dimension Temperature Programming System for Comprehensive Two-Dimensional Gas Chromatography. Part 2: Technical Improvements and Compatibility with Flow Modulation and Time-of-Flight Mass Spectrometry
Bibliographic record
Abstract
The second-dimension ( 2 D) temperature programming system ( 2 DTPS) for comprehensive two-dimensional gas chromatography (GC × GC) described in Part 1 was updated and tested with the time-of-flight mass spectrometer (TOFMS) and flow modulator. Addition of a real-time clock and remote port allowed the 2 DTPS to be a truly standalone system to be used with any GC × GC instrument. GC × GC reproducibility with the 2 DTPS was tested with thermal and flow modulation, coupled with the TOFMS and/or FID to demonstrate compatibility with all typical GC × GC setups. An improvement in the match factor, reverse match factor, and signal-to-noise ratio was found when performing 2 D temperature programming. Within-day and day-to-day reproducibility of the 2 DTPS for the 1 D retention time (≤0.04 and ≤0.05%), 2 D retention time (≤0.36 and ≤0.52%), and peak area (≤2.47 and ≤3.37%) were acceptable, while providing flexibility in 2 D optimization and improved peak capacity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.004 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.012 | 0.008 |
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 source (direct Gemma or distilled Codex), 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".