Method and means for vaporizing liquids for detection or analysis

An ion vapor source for obtaining an ion vapor from a liquid sample, said sample having ions of interest therein, the source comprising:

• (a) an electrically conductive capillary tube for receiving said sample, said tube defining a nozzle on one end thereof,
• (b) a means for supplying a liquid sample containing ions of interest to said capillary tube,
• (c) a heating means for applying electrical energy to a predetermined length of said conductive capillary tube for partially vaporizing the liquid sample passing through said capillary tube,
• (d) a control means for controlling the temperature of the sample within the capillary to maintain a constant fraction of the sample of liquid form as it is ejected from the nozzle as a thermospray of minute particles entrained in an intense vapor jet, said control means including a means for measuring the temperature of the liquid sample in the capillary, said means including a temperature sensor mounted in thermal contact with the capillary within a first third of the predetermined length heated by said heating means,
• whereby ions of interest are vaporized from the particles as a consequence of an electrical charge on the particles and the internal enthalpy of the particles.

An ion vapor source for obtaining ion vapor for a liquid sample, said sample having molecules of interest contained therein, said source comprising:

• (a) an electrically conductive capillary tube for receiving said sample, said tube defining a nozzle on one end thereof,
• (b) a means for supplying a liquid sample containing molecules of interest to said capillary,
• (c) a heating means for applying electrical energy to a predetermined length of said conductive capillary tube for partially vaporizing the liquid sample passing through said capillary tube,
• (d) a control means for controlling the temperature of the sample within the capillary to maintain a constant fraction of the sample in liquid form as it is ejected from the nozzle as a thermospray of minute particles entrained in an intense vapor jet, said control means including a means for measuring the temperature of the liquid sample in the capillary, said means including a temperature sensor mounted in thermal contact with the capillary within a first third of the predetermined length heated by said heating means,
• (e) a means for ionizing the selected molecules of interest after ejection from said nozzle.

A thermospray vaporizer for obtaining an ion vapor from a liquid sample for analysis of vaporized ions of interests, the vaporizer comprising:

• (a) a capillary tube means defining a discharge nozzle and an end thereof for passing the liquid sample therethrough;
• (b) a temperature sensing means for sensing the temperature of the liquid sample at a predetermined location within the vaporizer;
• (c) first heating means for heating a predetermined length of the capillary tube means and thereby heating the liquid sample passing therethrough;
• (d) control means for regulating the first heating means in response to the temperature sensing means to partially vaporize the liquid sample within the capillary tube and to form a thermospray of vapor having ions of interest in unvaporized minute particles, the thermospray having a constant proportion of vapor to unvaporized particles when discharged from the capillary tube means;
• (e) a means for purging the vapor from the ions of interest as said ions are selected for further analysis,
• (f) a moving belt arranged to receive said ions of interest, and a temperature transducer for regulating the temperature surrounding said belt.

A thermospray vaporizer for vaporizing a liquid sample containing large molecules of interest for analysis of the large molecules, the vaporizer comprising:

• (a) a capillary tube means in defining a discharge nozzle at an end thereof for passing the liquid sample therethrough;
• (b) a first heating means for heating a predetermined length of the capillary tube means and thereby heating the liquid sample passing therethrough;
• (c) a temperature sensing means for sensing the temperature of the liquid sample prior to the onset of vaporization, said means in intimate contact with said capillary, within a first third of the predetermined length heated by said heating means,
• (d) control means for regulating the first heating means in response to the temperature sensing means to partially vaporize the liquid sample within the capillary tube and to form a thermospray of vapor and unvaporized minute particles having said large molecules preferentially contained therein, the thermospray having a constant proportion of vapor to unvaporize particles when discharged from the capillary tube means;
• confining means forming a chamber for receiving at least the portion of the thermospray discharged from the capillary tube means to limit adiabatic expansion of the discharged vapor;
• and
• second heating means for heating the vapor within the confining means to vaporize substantially all of the discharged minute particles within the confining means by contact with the heated vapor.