Automatic analysis apparatus

An electrochemical automatic analyzer to measure a component bound to magnetic particles in a measurement liquid, the electrochemical automatic analyzer comprising:

• a first container which holds the measurement liquid;
• a measurement solvent supply bottle which holds a measurement solvent;
• a detector including a channel, one or more counter electrodes made of platinum, a working electrode in which platinum or gold occupies 50% or more of an elemental composition of a surface thereof, a reference electrode made of silver-silver chloride, and a magnet configured to apply a magnetic field;
• a nozzle and a syringe connected to the channel of the detector and configured to introduce the measurement liquid from the first container and the measurement solvent from the measurement solvent supply bottle into the detector;
• an inert gas container which holds an inert gas, an introduction channel connected between the inert gas container and the measurement solvent supply bottle and a supply valve which are configured to supply the inert gas into the measurement solvent in the measurement solvent supply bottle and degas a gas from the measurement solvent in the measurement supply bottle;
• a dissolved oxygen analyzer in the channel of the detector to measure a degassed state of the measurement solvent;
• a power supply;
• and
• a controller programmed to:
• control the nozzle and the syringe to introduce the measurement liquid into the channel of the detector and control the magnet to trap the magnetic particles on the working electrode;
• control the supply valve to supply the inert gas into the measurement solvent while controlling the nozzle and the syringe to introduce the measurement solvent into the channel of the detector;
• control the power supply to apply a voltage between the working electrode and the reference electrode and control the power supply to apply a predetermined voltage between the working electrode and the counter electrodes to detect a current corresponding to a concentration of the component in a state in which the measurement solvent is introduced into the channel of the detector,
• wherein the component is a chemical substance that is oxidized by applying a voltage of +1.2 V or more between the working electrode and the reference electrode, and
• wherein a measurement alarm is output when dissolved oxygen measured by the dissolved oxygen analyzer exceeds a predetermined amount.