Solution cathode glow discharge plasma-atomic emission spectrum apparatus and method capable of performing direct gas sample introduction and used for detecting heavy metal element

A microplasma apparatus used for analysis of metal elements by means of gas sampling,

• comprising a high-voltage power supply, a ballast resistor, a hollow metal anode, a waste reservoir located beneath the hollow metal anode, and a solution cathode;
• the hollow metal anode being connected to a positive electrode of the high-voltage power supply by means of the ballast resistor, and the solution cathode being connected to a negative electrode of the high-voltage power supply by means of a graphite electrode;
• the microplasma apparatus being further configured in such a manner that a discharge region is formed between the hollow metal anode and the solution cathode, and the hollow metal anode also serves as a sample introduction pipe so that the gas to be tested enters the discharge region and is excited;
• the solution cathode being an electrolyte solution introduced into a cathode capillary tube through a peristaltic pump and overflows the cathode capillary tube;
• the top end of the cathode capillary tube being kept at a distance of 3 to 4 mm from the bottom end of the hollow metal anode;
• the graphite electrode horizontally penetrating a wall of the waste reservoir and being fixed to one side of the waste reservoir;
• and
• the cathode capillary tube vertically penetrating the graphite electrode.