Mass spectroscope for liquid chromatograph

A mass spectrometer for a liquid chromatograph, said mass spectrometer comprising:

• an interface including an atomization chamber into which a liquid sample from said liquid chromatograph is sprayed to be converted into ions, an intermediate chamber at a reduced inner pressure and a detection chamber at a lower inner pressure than said intermediate chamber and containing a mass analyzer;
• a solvent-removing tube for causing liquid droplets containing said ions to pass therethrough from said atomization chamber into said intermediate chamber;
• means for causing said ions to travel along a travel path through said intermediate chamber into said detection chamber;
• a deflector having at least one pair of planar electrodes disposed inside said intermediate chamber and opposite each other sandwiching said travel path therebetween;
• a first voltage generating means for applying a variable DC voltage to said solvent-removing tube;
• a second voltage generating means for independently applying a different variable DC voltages to each of said electrodes;
• a memory storing data on optimum voltages to be applied to said solvent-removing tube and to said electrodes for optimizing efficiency with which ions with different mass numbers are received by said mass analyzer;
• and
• a control unit for applying a specified voltage to said mass analyzer and simultaneously controlling said first voltage generating means and said second voltage generating means so as to have selected voltages applied to said solvent-removing tube and to said electrodes, said selected voltages being selected according to said data stored in said memory.