Abstract: A batch chemical analyzer is disclosed, the analyzer including a reaction tank (100) in which sample and reagent are mixed, a detector (200), a switching valve (300), a multi-port valve (400), a pump (500) and an air suction/discharge hole (600), and particularly, the switching valve (300) includes a plurality of holes (301˜310) configured to receive sample and reagent and to send the same to the reaction tank (100) and the detector (200) for discharge to the outside, and the rotor (320) formed with a plurality of inlets (321˜325) simultaneously communicating with two adjacent holes of the plurality of holes (301˜310), whereby the two adjacent holes are differently paired to be communicated in two ways by the rotation of the rotor (320).

Abstract: An automatic chlorophyll analyzer and an analytical method for measuring fluorescence of chlorophyll after automatic processes of sample filtration and pigment extraction is disclosed, wherein the analyzer comprises: a flow path for fluid transfer; a multi-port valve for selectively connecting one of its ports with the said flow path; a filter for separating particulate materials from water sample and chlorophyll extract; a detector for measuring the fluorescence of chlorophyll extract; a syringe pump for picking up or dispensing the water sample; and a 4-port valve connected to the said syringe for selecting and switching flow paths.