Electrospray ionization mass spectrometry (ESI-MS)
procedure.
A Varian 1200L Quadrupole MS
instrument was used to analyze samples. Table 2 sh
ows instrument specifications. Samples were loaded
into a 5.0
μL sample loop using the Varian 1200L-LC-ESI Switch
ing Valve. A DI water mobile phase was set at a fl
ow rate
of 0.1 mL/min to carry the sample to the electrospr
ay. Varian MS Data Review software and Microsoft O
ffice
Excel 2003 were used to analyze the raw data.