A method for enriching and purifying nitrosamine precursors in water based on ion exchange technology

A nitrosamine precursor, ion exchange technology, applied in the field of analytical chemistry, can solve problems such as competitive interference, and achieve the effect of strong pertinence, elimination of interference, and strong force

Active Publication Date: 2018-04-10
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0016] To realize the enrichment and purification of precursors, it is first necessary to solve the problem of competitive interference of cations such as calcium and magnesium in water during the ion exchange process

Method used

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  • A method for enriching and purifying nitrosamine precursors in water based on ion exchange technology
  • A method for enriching and purifying nitrosamine precursors in water based on ion exchange technology

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Experimental program
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Embodiment approach 1

[0043] For the water sample of the target water source, first use a 0.45 μm polytetrafluoroethylene filter membrane to filter out insoluble matter, suspended matter and microorganisms, etc., to avoid interference with subsequent operations and detection, and then connect the filtered water to a 2L beaker or other glass containers. Use ion chromatography to measure the concentration of cations such as calcium and magnesium in water samples, and calculate the molar equivalent concentration of cations. Add 1mol / L sodium hydroxide solution to adjust the pH to 11.5, then add sodium-type 001×7 resin according to 6 times the total equivalent concentration of cations, and fully stir the reaction with a magnetic stirrer for 4 hours. Take the supernatant and add 1:5 hydrochloric acid to adjust the pH=3.0, and carry out the solid phase extraction operation. The solid-phase extraction operation requires automatic solid-phase extraction. The solid-phase extraction cartridge used is the PR...

Embodiment approach 2

[0046] For the water sample of the target water source, first use a 0.45 μm polytetrafluoroethylene filter membrane to filter out insoluble matter, suspended matter and microorganisms, etc., to avoid interference with subsequent operations and detection, and then connect the filtered water to a 2L beaker or other glass containers. Use ion chromatography to measure the concentration of cations such as calcium and magnesium in water samples, and calculate the molar equivalent concentration of cations. Add 1mol / L sodium hydroxide solution to adjust the pH to 11.5, then add sodium-type 001×7 resin according to 6 times the total equivalent concentration of cations, and fully stir the reaction with a magnetic stirrer for 4 hours. Take the supernatant and add 1:5 hydrochloric acid to adjust the pH=3.0, and carry out the solid phase extraction operation. The solid-phase extraction operation requires a semi-automatic solid-phase extraction instrument. The solid-phase extraction cartri...

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Abstract

The invention provides a method for enriching and purifying nitrosamine precursors in purified water based on the ion exchange technology and belongs to the field of analytical chemistry. The method is characterized in that a proper amount of sodium hydroxide is added into a water sample to adjust the pH of the water sample to be larger than or equal to 11.5, and enough sodium type strong-acid cation exchange resin is put to remove inorganic cation like calcium and magnesium; then supernatant liquor is taken, a proper amount of hydrochloric acid is added, and the pH of the water sample is adjusted to be smaller than or equal to 3.0; then the water sample passes through a pretreated cation exchange solid-phase extraction column, so that the nitrosamine precursors in the water are adsorbed to the cation exchange solid-phase extraction column; finally, 10% methyl alcohol ammonia water or a CaCl2 solution is selected to serve as strippant to elute the nitrosamine precursors away from the cation exchange solid-phase extraction column, so that a nitrosamine precursor solution with concentration improved greatly and high purity is obtained. The method has a good effect of holding back the nitrosamine precursors, the recovery rate and the concentration rate are high, enrichment and purification pertinence is high, and interference unrelated to neutral or negative electricity organism is eliminated.

Description

technical field [0001] The invention relates to a method for pretreatment, enrichment and purification of nitrosamine precursors in water, belonging to the field of analytical chemistry. Background technique [0002] Nitrosamines are an emerging class of disinfection by-products. At present, studies have confirmed that 9 kinds of nitrosamines such as dimethylnitrosamine (NDMA), diethylnitrosamine (NDEA) and dipropylnitrosamine (NDPA) can be disinfected in tap water, sewage and reclaimed water. generated during processing. Chloramine disinfectants commonly used in water treatment can react with nitrosamine precursors to generate higher concentrations of nitrosamines, and disinfectants or oxidants such as free chlorine and ozone can also react with precursors to generate nitrosamines. Although the concentration of nitrosamines in drinking water is generally only a few to tens of ng / L, it still has a strong risk of carcinogenicity. Nitrosamine substances such as NDMA are ver...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N30/06G01N30/08G01N30/14
CPCG01N30/06G01N30/08G01N30/14G01N2030/062G01N2030/146
Inventor 陈超李士翔贝尔张晓健汪隽
Owner TSINGHUA UNIV
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