Colorimetric test paper and its preparation method

Abstract

A colorimetry test paper and its preparing method, comprising thick chromatography filter paper layer, coloring reagent plate and white plastic substrate with window and white plastic substrate with window and coloring reagent plate are bonded to the thick chromatography filter paper layer, coloring reagent plate is on the position of window 6 of the with white plastic substrate with window whose film layer is on the coloring reagent plate and opposite to the window.

Description

technical field [0001] The invention belongs to the technical field of rapid and semi-quantitative determination of nitrite content, relates to a colorimetric test paper and a preparation method thereof, in particular to a colorimetric test paper with a multi-layer structure and a display for the colorimetric test paper Preparation method of color reagent sheet. Background technique [0002] Pollution-free food has strict regulations on the content of nitrite in fruits and vegetables. Its control standard NaNO 2 The content is allowed to be ≤4mg / L. Excessive intake will cause human hemoglobin to lose its oxygen transport capacity, and even generate carcinogenic nitrosamines. For the determination of nitrite content in fruits, vegetables and their products, the national standard method is N-naphthylethylenediamine spectrophotometry. For the specific determination method, please refer to "Determination of nitrite and nitrate content in fruits, vegetables and their products,...

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Problems solved by technology

For the determination of nitrite content in fruits, vegetables and their products, the national standard method is N-naphthylethylenediamine spectrophotometry. For the specific determination method, please refer to "Determination of nitrite and nitrate content in fruits, vegetables and their products, National Standard of the People’s Republic of China, GB / T15401-94.”, this method requires precipitation of protein under weakly alkaline conditions, removal of pigment and ascorbic acid, and extraction of nitrite with hot water at 70°C, the pretreatment of samples is relatively complicated

[0003] Simultaneously, the chromogenic agent N-naphthalene ethylenediamine or α-naphthylamine that adopts in above-mentioned measuring method mostly are poisonous reagent, have extremely unpleasant smell, hinder the health of operator, and easily cause environmental damage. Secondary pollution, coupled with the color reaction time of 15-25 minutes, makes the entire analysis time very lengthy, some may reach 3-5 hours, obviously not suitable for on-the-spot measurement at the sampling site

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