Flow injection analysis device for nitrite or nitrate in water

Abstract

The invention relates to a flow injection analysis device for nitrite or nitrate in water. The device comprises a photoelectric flow cell, a reactor, a developer bottle, a carrier liquid bottle, a copper-cadmium column, an injection pump of carrier liquid, a developer delivery pump, a sample delivery pump, a triple valve, a four-way valve and two six-way sampling valves, with the components and valves connected by capillaries. In the device, a phosphoric acid solution with a pH of 1.8 is taken as the carrier liquid which is continuously injected into the pipelines of the capillaries by the constant-current injection pump. A quantitative water sample and a developer are pitched into the carrier liquid by the sampling valves. Then the water sample diffuses in the oriented flowing carrier liquid and mixes and reacts with the developer, and the reaction liquid is brought into the colorimetric flow cell (i.e. the photoelectric flow cell) by the carrier liquid. After absorption of lights with a wavelength of 540nm and photoelectric conversion, an absorbance value can be tested. And finally, the carrier liquid flows out of the outlet capillaries of the flow cell. With accurate test data and substantially shortened test period, the analysis device of the invention is suitable for rapid detection of nitrite and nitrate.

Description

technical field [0001] The invention relates to a water quality nitrite or nitrate flow injection analysis device for rapid analysis or on-line monitoring of nitrite or nitrate in surface water or solution. Background technique [0002] Nitrate and nitrite are extremely harmful to human health. Long-term intake of nitrate or nitrite will cause mental decline. Children who drink water with high nitrate or nitrite content for a long time will have better auditory and visual conditioned reflexes. slow. In addition, it can also cause endemic goiter, and interfere with the normal utilization of vitamin A by the body, leading to vitamin A deficiency, decreased blood quality, nerve inhibition, and tachycardia. Nitrate can be converted into nitrite in the stomach of the body, and under the action of various nitrogen-containing organic compounds (amines, amides, urea, cyanamide, etc.), it will form direct carcinogenic, teratogenic, and mutagenic substances with chemical stability. ...

AI Technical Summary

Problems solved by technology

Although polarography and chromatography have high sensitivity, they have poor precision, require harsh analysis conditions, and the instruments are expensive, making it difficult to popularize them.

These existing detection methods inevitably have various shortcomings such as cumbersome operation, lengthy and time-consuming steps, large reagent consumption, and many interference factors, so fast online analysis cannot be realized.

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