Multi-passage direction selecting flow-injection quick analysis system for hexavalent chromium water quality

Abstract

The invention relates to a multi-passage direction selecting flow-injection quick analysis system for hexavalent chromium water quality. A photoelectric flow cell, a reaction tube, an injection pump, an indicator storage bottle and a carrier fluid storage bottle are connected with a multi-passage direction selecting valve through a capillary pipeline; a valve cover of the multi-passage direction selecting valve is provided with a direction selecting connector which can be communicated with one of connectors of an upper valve seat through the rotation of the valve cover; the direction selecting connector of the valve cover is connected with the injection pump through a capillary storage pipe; the connectors of the valve seat are connected with the reaction tube, a water sample source, two guide samples, the indicator bottle and the carrier fluid bottle respectively; and the photoelectric flow cell is connected with an outlet of the reaction tube. The system makes the quantitative water sample and the diphenylcarbazide indicator continuously flow along with the carrier fluid in a continuous flow-injection mode; the water sample and the indicator diffuse in the carrier fluid and react to generate red fluid; and the content of hexavalent chromium in the water sample is measured through the photoelectric flow cell. The system has the advantages of simple structure, convenient operation and quick measurement, and is applicable to on-line real-time monitoring of the hexavalent chromium water quality.

Description

technical field [0001] The invention relates to a rapid water quality analysis system for hexavalent chromium by flow injection and spectrophotometry, which is used for rapid analysis or analysis of hexavalent chromium content in water sources such as surface water or factory discharge water. The online monitoring belongs to the field of chemical analysis and water environment monitoring and analysis. Background technique [0002] Hexavalent chromium compounds are commonly used in metal plating, tanning electronics industry and various metal industries. In addition, they are also used in colorants in pigments (that is, lead chromate) and heat-absorbing pumps in cooling water circulation systems, industrial freezers and Corrosion inhibitor (sodium dichromate) in refrigerator heat exchangers. [0003] Hexavalent chromium is extremely toxic. It can cause vomiting and abdominal pain when it invades through the digestive tract. It can cause dermatitis and eczema when it invades ...

AI Technical Summary

Problems solved by technology

The polarographic method and the direct current method can directly measure ultra-trace amounts of hexavalent chromium (the analysis accuracy can reach (10 -3 mg / L), neutron activation method and isotope dilution mass spectrometry have high sensitivity and high selectivity, but due to limited conditions, these methods have not been widely used

Most of the other methods are difficult to be widely used due to the expensive equipment

[0005] Flow injection analysis is a new rapid analysis technology, which has developed rapidly in recent years, but the flow injection analysis system currently used to detect hexavalent chromium has shortcomings such as short service life and high failure rate

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