The binary mixture of BTTN and NG was separated and determined by means of simultaneous techniques of API-ES-LC-MS. Through the reversed-phase high performance liquid chromatography,BTTN and NG were separated on the C₁₈ column. The detection was performed at 225 nm. The mobile phase was a mixture of methanol and water(1：1,V/V) at a flow rate of 0.2 ml·min^-1. The influence of CapEx voltage,pH of sample solution,temperature of a counter flow of neutral,heated dying gas(T) and ionization mode on the mass spectra of BTTN and NG was studied. The results show that under the conditions of CapEx voltage=-100 V,pH=7 and T=100 ℃,the perfect mass spectra of BTTN and NG were obtained using the negative ion mode.