Waters 2690 hplc

Manually collected C-glycosyl flavones in aqueous ethanol fraction were tested for their purity according to the method described in Section 2.4. HPLC–ESI–MS analysis was done on a Waters platform ZMD 4000 system composed of a micro ZMD mass spectrophotometer, a Waters 2690 HPLC and a Waters 996 photo diode array detector (Waters corporation, MA, USA). Data were collected and processed via a personal computer running Mass Lynx software version 3.1 (Micromass, a diversion of Waters corporation, MA, USA). The samples in 10 μl diluted aliquot were separated on a reversed phase C18 column (4.6 × 250 mm), using a diode array detector (operating at 337 nm). Solvent A water: formic acid (99:1) and solvent B methanol: formic acid (99:1) was used as mobile phase at a flow rate of 1 ml/min for a total run time of 40 min. UV–vis absorption spectra were recorded on-line during HPLC analysis. The following ion optics was used- capillary voltage 3.5 kV, cone voltage 100 V and collision voltage 10 V. The source block temperature was 120 °C and the desolvation temperature was 350 °C. ESI–MS was performed using argon as cone gas (50 l/h) and nitrogen as desolvation gas (500 l/h). The electron spray probe flow was adjusted to 70 ml/min. Continuous mass spectra were recorded over the range of m/z 100–1000 with scan time 1 s and inter scan delay 0.1 s.