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Year of synthesis
1883
Synonyms and Molecular Information
- Basic Yellow 2, C.I. 41000
- Commercial names: Auramine O, Auramine II
- IUPAC Name: 4-[4-(dimethylamino)benzenecarboximidoyl]-N,N-dimethylaniline
- CAS Number: 2465-27-2
- Dye class: Diarylmethane
- Molecular Formula : C17H22N3+
- Molecular Weight = 268.1808 g/mol
Analytical instrumentation and procedures
Extraction: The sample (ca. 2 mm of a thread) was put in 2 mL vials, admixed with 200 μL DMSO and heated at 80 °C for 10 min. After centrifugation, the supernatant was transferred into another vial. The residue was admixed with 200 μL of methanol/acetone/water/0.5 M oxalic acid 30:30:40:1 (v/v/v/v) and heated at 80 °C for 15 min. The solution was evaporated under N2 and reconstituted using 200 μL of MeOH/H2O 1:1 (v/v). The DMSO extract was combined with the oxalic acid extract and the solution was centrifuged for 10 min. The supernatant was transferred to a fresh 250 μL insert and 5–10 μL of the solution were injected into the HPLC system.
HPLC-DAD-ESI-Q-ToF system: Analyses were carried out using a 1260 Infinity HPLC (Agilent Technologies), coupled to a 1260 DAD detector (Agilent Technologies) and to a Quadrupole-Time of Flight tandem mass spectrometer 6530 Infinity Q-ToF detector (Agilent Technologies) by a Jet Stream ESI interface (Agilent Technologies). Separation was achieved using a Zorbax Extend- C18 column (2.1 mm ⨯ 50 mm, 1.8 μm particle size) with a 0.4 mL/min flow rate and 40 °C column temperature, and a gradient of water with 0.1% formic acid (eluent A) and acetonitrile with 0.1% formic acid (eluent B). The elution gradient was programmed as follows: initial conditions 95% A, followed by a linear gradient to 100% B in 10 min, and held for 2 min. Re-equilibration time for each analysis was 10 min. 5 μL injection volume was adopted for MS experiments and 10 μL for MS/MS experiments. The DAD detector (cell volume 50 μL) scanned in the range 190–700 nm with 2 nm resolution. The ESI operating conditions were: drying gas (N2, purity >98%) temperature 350 °C and 10 L/min flow; capillary voltage 4.0 kV; nebulizer gas pressure 40 psig; sheath gas (N2, purity >98%) temperature 375 °C and flow 11 L/min. High resolution MS and MS/MS spectra were acquired in both negative and positive ionisation modes in the range 100–1700 m/z. The fragmentor was kept at 150 V, nozzle voltage 1000 V, skimmer 65 V, octapole RF 750 V. For the MS/MS experiments, different voltages were tested for Collision Induced Dissociation (CID), to maximise the information obtained from the fragmentation of the parent ions. The collision gas was N2 (purity 99.999%). The data were collected by targeted MS/ MS acquisition with an MS scan rate of 1.0 spectra/sec and a MS/MS scan rate of 1.0 spectra/sec. Auto-calibration was performed daily using Agilent tuning mix HP0321 (Agilent Technologies) prepared in 90% water-10% acetonitrile. MassHunter® Workstation Software was used to carry out mass spectrometer control, data acquisition, and data analysis.
Chromatograms and Mass Spectra
Basic Yellow 2, C.I. 41000, DAD Chromatogram at 350 nm By Diego Tamburini, The British Museum, London
Results
References
Tamburini, D., On the reliability of historic books as sources of reference samples of early synthetic dyes – The case of “The Coal Tar Colours of the Farbwerke vorm. Meister, Lucius & Brüning, Höchst on the Main, Germany – A General Part” (1896). Dyes and Pigments, 2024. 221: p. 111796.