Low-detection lower limit total arsenic on-line analyzer and analytical method thereof

Abstract

The invention discloses a low-detection lower limit total arsenic on-line analyzer, which comprises a cuvette, a measuring light source arranged on one side of the cuvette, and a photoelectric conversion module which is arranged on the other side of the cuvette and corresponds to the position of the measuring light source. The cuvette is connected with the inlet/outlet pipe of a multi-way valve by a pipe; other inlet/outlet pipes of the multi-way valve are respectively connected with a sulfuric acid reagent bottle, a distilled water bottle, a color developing agent bottle, a sample bottle, a screening agent reagent bottle, a thinning chamber, a waste liquor barrel and a dosing device by pipes; the dosing device is connected with a peristaltic pump through a pipe; and the multi-way valve is electrically connected with a control module which is electrically connected with the dosing device, the peristaltic pump and a man-machine interface. The invention further discloses a method for analyzing a water sample by using the low-detection lower limit total arsenic on-line analyzer . The invention has the advantages of precise dosing, capability of effectively reducing the measurement error, low cost, and capability of effectively reducing the detection lower limit of the total arsenic.

Description

technical field [0001] The invention relates to a total arsenic analyzer, in particular to a total arsenic on-line analyzer with a low detection limit and an analysis method thereof. Background technique [0002] Arsenic (As) is a non-essential element for the human body. Elemental arsenic has low toxicity, while arsenic compounds are highly toxic. Trivalent arsenic compounds are more toxic than pentavalent arsenic compounds, and organic arsenic is highly toxic to humans and organisms. Arsenic accumulates through the respiratory tract, digestive tract, bones, muscles, etc., especially in hair and nails, causing chronic arsenic poisoning, and the incubation period can be as long as several years or even decades. Chronic arsenic poisoning has digestive system symptoms, nervous system symptoms and skin lesions. Arsenic is also carcinogenic and can cause skin cancer. In general, soil, water, air, plants, and the human body contain trace amounts of arsenic. Arsenic pollution m...

AI Technical Summary

Problems solved by technology

Atomic absorption, atomic fluorescence, and plasma emission spectrometry have the advantages of high sensitivity, simplicity, speed, and less interference. However, due to the high development costs and technical difficulties of these methods for online monitoring, it is still difficult to realize arsenic on a large scale. Therefore, the automatic online monitoring of total arsenic in water is mainly realized by colorimetric and electrochemical methods. The online monitors using electrochemical methods are still at the level of mercury electrodes, rather than mercury electrodes. The manufacturing process, the anti-interference ability of the electrode itself to the pollution source water sample, and the automatic cleaning technology of the electrode surface are still difficult to meet the technical requirements of automatic online monitoring. In contrast, the colorimetric method has good stability, low instrument development cost, Advantages of easy operation and maintenance

However, all the heavy metal series water quality online monitoring instruments currently using colorimetry in China are still not ideal in terms of monitoring sensitivity, especially the total arsenic online analyzer, due to many defects in its color development process and control process, the lower limit of detection is not very good. The non-detectable limit of 0.5mg / L stipulated in the Comprehensive Sewage Discharge Standard (GB8978-1996) obviously fails to meet the non-detectable limit of 0.01mg / L stipulated in the Hygienic Standard for Drinking Water (GB5749-2006)

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