Determination of Dicyclohexylamine in Beeswax by Aqueous Normal Phase Liquid Chromatography Coupled With Tandem Mass Spectrometry
Bibliographic record
Abstract
Dicyclohexylamine (DCH) is an excipient present in commercial formulations of fumagillin (Fumagilin-B® and Fumidil-B®), an antibiotic which is employed in apiculture for the control of nosema disease. DCH has been demonstrated to be stable in harvested honey; however, its fate in the beehive has not been investigated. In this study, DCH residues were determined in beeswax samples collected from brood chambers and honey supers from various apiaries throughout Alberta. The determination of DCH was performed using a simple extraction procedure followed by low-temperature cleanup and finally analysis with aqueous normal phase liquid chromatography-electrospray ionization tandem mass spectrometry. The method was found to yield high accuracy and precision (94.9 ± 1.7% to 110.8 ± 6.6%) for replicate beeswax samples spiked with 4, 80, 360 and 2,000 μg kg-1 of DCH. With a limit of quantification of 1 μg kg-1, 100% of the 61 beeswax samples analyzed were found to contain residues of DCH ranging from 15 to 6,410 μg kg-1. The results indicate that DCH can accumulate in beeswax when Fumagilin-B® or Fumidil-B® is applied in apiculture and that these concentrations can vary significantly among beekeeping operations.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| 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 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".