Appendix A. Methods of HPLC-MS analysis of Gelsemium nectar samples.
Lyophylized sample + 500µL MeOH
Column: Merck LiChroCART RP-18 (5 µm, 250 mm × 4 mm)
Mobile phase: A: water + 0,1% formic acid and B: Acetonitril
Linear gradient from 30 to 100% acetonitril in 20 min
Flow rate: 1 mL/min
Detection wavelength DAD: 280 nm
Capillary voltage: 3.50 kV
Cone voltage: 45 V
Source temperature: 120°C
Flow rate: 100µL/min
Injection volume: 20µL
Sample amount was estimated from total ion current using a response factor.