Determination of Quercetin by Dual-wavelength Overlapping Spectrophotometry
Bibliographic record
Abstract
An UV-spectrophotometric method for the determination of quercetin was reported.In a B-R buffer medium of pH=7.45,two absorption peaks at the wavelength of 256 nm and 368 nm were observed,and the sum of absorbance at these two peaks showed good linearity with quercetin concentration in the range of 0.84～42.0 μg\5mL-1.The apparent molar absorptivity was 4.24×104 L\5mol-1\5cm-1 which was 86.8% higher than that obtained under the conventional single wavelength measurement mode.Detection limit of the proposed method was found to be 0.30 μg\5mL-1.The method was applied to the determination of quercetin in Jiangzhining capsules.The relative standard deviation of results was no more than 3.23%,and the values of recovery test obtained by the standard addition method were in the range of 95.2%～102.7%.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| 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".