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CN-122016778-A - Method for detecting ferrous ions of heavy metals in environment

CN122016778ACN 122016778 ACN122016778 ACN 122016778ACN-122016778-A

Abstract

The invention discloses a detection method of heavy metal ferrous ions in environment, which belongs to the field of heavy metal ion detection and comprises the following steps of (1) adding a chromogenic agent tetra (4-carboxyphenyl) porphyrin and a surfactant into a sample to be detected, regulating the pH value of a system to be acidic, uniformly mixing, standing for reaction, and (2) measuring the absorbance of a solution by adopting a spectrophotometry after the reaction is completed, and calculating the concentration of ferrous ions in the sample to be detected according to a standard curve of ferrous ions. The method of the invention generates stable orange-red complex by the reaction of ferrous ions and the color developing agent, has the characteristics of high sensitivity, strong anti-interference capability and stable color developing agent, and changes the defects of low sensitivity, poor anti-interference capability and poor color developing agent stability in the existing phenanthroline spectrophotometry for measuring ferrous ions. The method of the invention does not need to rely on large-scale instruments and equipment, is simple and convenient to operate, and is very suitable for rapid detection of trace ferrous ions in water.

Inventors

  • ZHAO BO
  • ZHANG DONG
  • CHEN LIUYANG
  • DU BINGNAN
  • MA JIALE
  • CHEN XUEYING
  • Jie Jiawei
  • WANG CHUANXIAN
  • WANG LIANGZI

Assignees

  • 南京师范大学

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The method for detecting the ferrous ions of the heavy metals in the environment is characterized by comprising the following steps of: (1) Adding a chromogenic agent tetra (4-carboxyphenyl) porphyrin and a surfactant into a sample to be detected, regulating the pH value of the system to be acidic, uniformly mixing, and standing for reaction; (2) After the reaction is completed, measuring the absorbance of the solution by adopting a spectrophotometry, and calculating the concentration of ferrous ions in the sample to be measured according to a standard curve of the ferrous ions; The structural formula of the color reagent tetra (4-carboxyphenyl) porphyrin is shown as follows: 。
  2. 2. The method for detecting heavy metal ferrous ions in environment according to claim 1, wherein the preparation of the indicator tetra (4-carboxyphenyl) porphyrin in the step (1) is that pyrrole and 4-carboxybenzaldehyde are added into acetic acid for reflux reaction, then absolute ethyl alcohol is added after the mixture is cooled, the temperature is reduced to room temperature under stirring, stirring is continued, standing is carried out at low temperature, products are collected through vacuum filtration, and the tetra (4-carboxyphenyl) porphyrin is obtained after washing and drying.
  3. 3. The method for detecting ferrous ions of heavy metals in the environment according to claim 1, wherein the surfactant in the step (1) is any one or a combination of more than one of hydroxylamine hydrochloride, tween-80 and sodium dodecyl sulfate, the addition amount of the surfactant is 0.4-2.0 mL, and the concentration is 1-5%.
  4. 4. The method for detecting ferrous ions of heavy metals in an environment according to claim 1, wherein the surfactant in the step (1) is hydroxylamine hydrochloride.
  5. 5. The method for detecting ferrous ions of heavy metals in an environment according to claim 1, wherein the adding amount of the color reagent tetra (4-carboxyphenyl) porphyrin in the step (1) is 0.2-5.0 mL, and the concentration is 0.1-2.5 g/L.
  6. 6. The method for detecting ferrous ions of heavy metals in the environment according to claim 1, wherein in the step (1), the pH of a system is adjusted to 3-6 by adopting hydrochloric acid or sulfuric acid.
  7. 7. The method for detecting ferrous ions of heavy metals in the environment according to claim 1, wherein the reaction time is 5-30 min after uniform mixing in the step (1), and the temperature is 10-60 ℃.
  8. 8. The method for detecting ferrous ions of heavy metals in an environment according to claim 1, wherein in the step (2), spectrophotometry is adopted to measure the absorbance of the solution, and the maximum absorption wavelength of ferrous ions is 441 nm.
  9. 9. The method for detecting ferrous ions of heavy metals in an environment according to claim 1, wherein the environment comprises a water environment or a soil environment.
  10. 10. Use of a color reagent tetra (4-carboxyphenyl) porphyrin used in the method for detecting heavy metal ferrous ions in the environment according to claim 1 in spectrophotometry detection of heavy metal ferrous ions in the environment.

Description

Method for detecting ferrous ions of heavy metals in environment Technical Field The invention belongs to the field of heavy metal ion detection, and particularly relates to a detection method of heavy metal ferrous ions in the environment. Background Iron ions play a central role in natural circulation and human activities and are widely distributed in natural water and soil environments. In the environmental field, the content of Fe 2+ in groundwater and surface water directly indicates the oxidation-reduction state and dissolved oxygen level of the water body, and the dynamic change of the Fe 2+ not only affects the water quality sense, drives the pollutant migration, but also can cause ecological hypoxia, so the Fe 2+ is a key parameter for evaluating the safety of drinking water and the balance of an ecological system. The Fe 2+ has complex environmental behaviors, and the oxidation-reduction process directly regulates and controls the morphological transformation and migration of heavy metals, the degradation of organic pollutants and the bioavailability of phosphorus in water, so that the health of the whole ecological system, the water quality safety and the soil function are deeply influenced. Therefore, the concentration monitoring and the morphological identification of Fe 2+ in the environment are accurate and timely, and are important for evaluating the environmental pollution condition, tracing the pollution source, researching the geochemical behavior of elements and implementing effective environment management and restoration strategies. The Fe 2+ is measured by adopting a phenanthroline spectrophotometry according to the current industry standard HJ/T345-2007, the lowest detection concentration is 0.03 mg/L, the sensitivity is low, the detection item with high sensitivity requirement cannot be met, the phenanthroline serving as a color developing agent is easy to decompose in visible light, the stability is poor, the shelf life is short, the phenanthroline can form a colored complex with various metal ions, and the anti-interference capability is poor. Therefore, development of a rapid detection method of Fe 2+ with high sensitivity, good color reagent stability and strong anti-interference capability is needed. Disclosure of Invention The invention aims to: in order to solve the technical problems, the invention aims to provide a detection method of heavy metal ferrous ions in the environment, the detection method adopts a specific detection method and detection conditions, the adopted color reagent tetra (4-carboxyphenyl) porphyrin contains coordination sites with high affinity with Fe 2+, the method has high sensitivity, the method has the advantages of high stability, simple operation, capability of effectively and simultaneously detecting the content of Fe 2+ in water such as industrial wastewater, simple detection method and high sensitivity, can completely meet the current maximum limit requirement, is a novel method for detecting heavy metal ferrous ions in water, and is easy to popularize and use, and has very strong innovation significance and practical value. The detection method of the heavy metal ferrous ions in the environment comprises the following steps of: (1) Adding a chromogenic agent tetra (4-carboxyphenyl) porphyrin and a surfactant into a sample to be detected, regulating the pH value of the system to be acidic, uniformly mixing, and standing for reaction; (2) After the reaction is completed, measuring the absorbance of the solution by adopting a spectrophotometry, and calculating the concentration of ferrous ions in the sample to be measured according to a standard curve of the ferrous ions; The structural formula of the color reagent tetra (4-carboxyphenyl) porphyrin is shown as follows: 。 the preparation method of the display agent tetra (4-carboxyphenyl) porphyrin in the step (1) comprises the steps of adding pyrrole and 4-carboxybenzaldehyde into acetic acid for reflux reaction, then cooling the mixture, adding absolute ethyl alcohol, cooling to room temperature under stirring, continuously stirring, standing at a low temperature, vacuum filtering to collect a product, washing and drying to obtain the tetra (4-carboxyphenyl) porphyrin. The preparation method of the color reagent tetra (4-carboxyphenyl) porphyrin comprises the steps of adding pyrrole and 4-carboxybenzaldehyde into acetic acid, and heating and refluxing at 135 ℃ for 1 hour. The mixture was then cooled to 80 ℃, absolute ethanol was added, and the temperature was reduced to room temperature with stirring for 3 hours. The mixture was then stored in a refrigerator for 24 hours. The product was collected by vacuum filtration and washed with cold acetone. After vacuum drying, a color developer is obtained. Preferably, the color reagent preparation method adds 4.0 mL pyrrole and 8.59 g 4-carboxybenzaldehyde into 120 mL acetic acid, and heat reflux is carried out for 1 hour at 135 ℃. The mixture was then