Plasma Amino Acid Analysis by Tandem Mass Spectrometry: A comparison to Amino acid analyzer
Bibliographic record
Abstract
Objective: To validate use of tandem mass spectrometry in the analysis of plasma amino acids in comparison to a dedicated amino acid analyzer. Introduction: Plasma amino acid analysis in regularly performed on a dedicated amino acid analyzer that utilizes a ninhydrin based HPLC technique. Sample run times are long with no resolution between citrulline and homocitrulline. Method: 111 plasma samples were obtained on an anonymous basis and were anayzed on the Biochrome® and API2000 tandem mass spectrometry (MS/MS) for Ala, Arg, Cit, Gly, His, Leu, Met, Orn, Phe, Pro, Tyr, Homocit and Val. Sample preparation for MS/MS involved methanolic precipation, derivatization to the respective dibutyryl ester derivatives of the amino acids and detection by MS/MS. Results: All the amino acids showed good correction (r=0.92–0.99) between the two instruments. In addition, MS/MS was able to distinguish between Cit and Homocit, provided greater sensitivity and specificity and faster turn around time(TAT) (total TAT of 30 min). Conclusion: MS/MS can provide equal or even better service in amino acid analysis as is with dedicated amino acid analyzers.
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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 | 0.007 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".