Apparatus for automatically generating and measuring gaseous measuring samples from a series of liquid samples

An automatic system for generating gaseous samples from liquid samples and reagents and for transferring gaseous samples for measurements in an atomic absorption spectrometer, said system comprising:

• means defining a reaction chamber having a first outlet in communication with an absorption spectrometer measuring cuvette and first, second, and third inlets for injecting liquid samples and first and second liquid reagents respectively into said chamber;
• pumping means for withdrawing the liquid sample and the liquid reagents from respective supply vessels and injecting the sample and reagents through their respective inlets;
• said system further including a fourth inlet to said chamber for admitting an inert gas, means adjacent the internal surface of the wall of said chamber for directing the injected liquids for flow in a first direction, said fourth inlet being positioned in said chamber to admit gas into said chamber for flow in a second direction substantially opposite to said first direction to carry the gas from the liquid sample countercurrent to the direction of the liquids flow and toward the spectrometer;
• pump timing means for controlling the withdrawal and injection of sample and liquid reagents by said pumping means and operable in a plurality of discrete time periods within a test cycle including a first time period and a second time period subsequent to said first time period;
• said pump timing means being operable during said first and second time periods to control said pumping means to substantially continuously inject liquid reagents at a substantially uniform rate into said reactor chamber;
• said pump timing means being operable during said second time period to control said pumping means to substantially continuously inject liquid sample into said reactor at a substantially uniform rate, thereby enabling spectrometer analyses during said first and second time periods to provide indications of the amount of the element of interest contained in the liquid reagents and the amount of the element of interest contained in both the reagents and the liquid sample, respectively.

An automated system for generating gaseous samples from liquid samples and reagents and for transferring gaseous samples for measurements in an atomic absorption spectrometer, said system comprising:

• means defining a reaction having a first outlet in communication with an absorption spectrometer measuring cuvette and first, second, and third inlets for injecting liquid samples and first and second liquid reagents respectively into said chamber;
• pumping means for withdrawing the liquid sample and the liquid reagents from respective supply vessels and injecting the sample and reagents through their respective inlets;
• pump timing means for controlling the withdrawal and injection of sample and liquid reagents by said pumping means and operable in a plurality of discrete time periods within a test cycle including a first time period and a second time period subsequent to said first time period;
• said pump timing means being operable during said first and second time periods to control said pumping means to substantially continuously inject liquid reagents at a substantially uniform rate into said reactor chamber;
• said pump timing means being operable during said second time period to control said pumping means to substantially continuously inject liquid sample into said reactor at a substantially uniform rate, thereby enabling spectrometer analyses during said first and second time periods to provide indications of the amount of the element of interest contained in the liquid reagents and the amount of the element of interest contained in both the reagents and the liquid sample, respectively;
• said reactor chamber being generally cylindrical and having upper and lower end portions, said first outlet being adjacent said upper portion, a second outlet located adjacent said lower portion for draining liquid waste from said reactor chamber, a fourth inlet to said chamber for admitting an inert carrier gas, means adjacent the internal surface of said cylindrical chamber for directing the injected liquid for flow in a first direction, said fourth inlet being disposed adjacent said lower portion to admit carrier gas into said chamber for flow in a second direction substantially opposite to said first direction to carry the gas from the liquid sample countercurrent to the direction of the liquids flow and towards the spectrometer, a liquid sample carrier for receiving a plurality of liquid sample vessels, a support for a wash liquid receptacle, said pumping means including a withdrawal conduit, means responsive to said timing means for locating said conduit and said sample carrier relative to one another to withdraw sample liquid from a selected liquid sample vessel during said first time period and for locating said conduit and said support relative to one another for withdrawing wash liquid from the wash liquid receptacle during the third time period of said measuring cycle, said conduit lying in communication with said first inlet, discrete supply vessels for the first and second liquid reagents respectively and conduits coupling said first and second reagent supply vessels and said second and third inlets respectively.