Method for accurately detecting heavy metal content of tea leaves

A detection method and technology for heavy metals, which are applied in measurement devices, biological tests, material inspection products, etc., can solve the problems of difficult detection of heavy metals, inability to directly apply the liquid to be tested, and unfriendly environment, so as to improve detection accuracy and overcome difficult The effect of being detected and facilitating subsequent detection

Inactive Publication Date: 2019-02-22
广西驰胜农业科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Among them, the pretreatment is to convert the sample into a liquid solution for measurement, and the test solution obtained by the above pretreatment method is strongly acidic, which is not only unfriendly to the environment, but also has potential safety hazards in manual operation. In addition, the strong acid test solution cannot For all detection methods, such as enzyme-linked immunoassay cannot be carried out in a strong acid environment, so the test solution obtained by traditional pretreatment methods cannot be directly applied to enzyme-linked immunoassay; in addition, the presence of heavy metals in tea There are free state and complexed state, and the heavy metals in the complexed state are not easy to be detected, resulting in inaccurate detection results. Therefore, the applicant improved the pre-treatment based on the defects in the current detection to overcome the above defects.

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  • Method for accurately detecting heavy metal content of tea leaves

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Embodiment 1

[0020] In this embodiment, an accurate detection method of heavy metal content in tea leaves includes the following steps:

[0021] (1) Sample pretreatment: pulverize the tea to be tested to 60 meshes, add 8 times the amount of water, 300W ultrasonic treatment for 30min to obtain a treatment solution, adjust the pH of the treatment solution to 3, and add 2% of the weight of the treatment solution 30% hydrogen peroxide, 4% 1mol / L ferrous sulfate, stir for 40 minutes, adjust the pH to 7, and then add 15% heavy metal flocculant by weight of the treatment solution, mix and stir, and let stand until flocculent precipitation Separate, centrifuge, collect the precipitate, wash with water until there is no powder on the surface of the precipitate; the preparation method of the heavy metal flocculant is: peel off the capers seeds, grind them, add them to a citric acid solution with a mass concentration of 50% and boil them continuously Boil for 30 minutes, cool, and stand until precipitat...

Embodiment 2

[0025] In this embodiment, an accurate detection method of heavy metal content in tea leaves includes the following steps:

[0026] (1) Sample pretreatment: pulverize the tea to be tested to 80 mesh, add 10 times the amount of water, 600W ultrasonic treatment for 50min to obtain a treatment solution, adjust the pH of the treatment solution to 4, and add 3% by weight of the treatment solution 30% hydrogen peroxide, 6% 1mol / L ferrous sulfate, stir for 60 minutes, adjust the pH to 8, then add 30% heavy metal flocculant by weight of the treatment solution, mix and stir, and let stand until flocculent precipitation Separate, centrifuge, collect the precipitate, wash with water until there is no powder on the surface of the precipitate; the preparation method of the heavy metal flocculant is: peel off the capers seeds, grind them, add them to a citric acid solution with a mass concentration of 65%, and boil them. Boil for 50 minutes, cool, and stand until the precipitate precipitates. ...

Embodiment 3

[0030] In this embodiment, an accurate detection method of heavy metal content in tea leaves includes the following steps:

[0031] (1) Sample pretreatment: crush the tea leaves to be tested to 70 meshes, add 9 times the amount of water, 400W ultrasonic treatment for 40 minutes to obtain a treatment solution, adjust the pH of the treatment solution to 3.5, and add 2.5% by weight of the treatment solution to the mass 30% hydrogen peroxide, 5% 1mol / L ferrous sulfate, stir for 50 minutes, adjust the pH to 8, then add 25% heavy metal flocculant by weight of the treatment solution, mix and stir, and let stand until flocculent precipitation Separate, centrifuge, collect the precipitate, wash with water until there is no powder on the surface of the precipitate; the preparation method of the heavy metal flocculant is: peel the capers seeds, grind them, add them to a citric acid solution with a mass concentration of 60%, and boil them. Boil for 40 minutes, cool, and let it stand until th...

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Abstract

The invention discloses a method for accurately determining the heavy metal content of tea leaves, relating to the technical field of heavy metal determination of foods. The method comprises the stepsof crushing to-be-determined tea leaves, adding the tea leaves into water, carrying out ultrasonic treatment, adding hydrogen peroxide and ferrous sulfate for treatment, adding a heavy metal flocculant so as to separate precipitates, adding xylanase into the precipitates, carrying out water-bath enzymolysis until the precipitates are completely hydrolyzed so as to obtain to-be-determined liquid,and determining the contents of lead, chrome, cadmium and copper in the to-be-determined liquid by virtue of an enzyme-linked immunoassay method. By optimizing a pretreatment method, the to-be-determined liquid which does not contain acid is obtained, is safe and environment-friendly and can be applied to the enzyme-linked immunoassay method, and a determination result is accurate.

Description

【Technical Field】 [0001] The invention relates to the technical field of food heavy metal detection, in particular to an accurate detection method of tea heavy metal content. 【Background technique】 [0002] Tea is one of the three major beverages in the world. In recent years, the rapid development of industrialization and urbanization has exposed the production of tea in many places to the polluted environment. The content of heavy metals such as lead, chromium, cadmium, and copper in tea has a rising trend. Drinking tea with excessive pollutants will cause harm to human health, and heavy metal content testing is required. [0003] The detection of heavy metals in tea mainly includes two steps: pretreatment and detection. The commonly used detection methods at this stage are: atomic absorption spectrophotometry, inductively coupled plasma mass spectrometry, atomic fluorescence spectroscopy, enzyme-linked immunoassay, etc., and the commonly used pretreatment methods are wet digest...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N33/53G01N1/28G01N1/34
CPCG01N1/286G01N1/34G01N33/53
Inventor 谢宗宜
Owner 广西驰胜农业科技有限公司
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