Test paper for quickly detecting urea in liquid milk and preparation method thereof

A technology of test paper and urea, which is applied in the field of chemical detection, can solve the problems that can only be used in the laboratory, the high cost of new desktop and portable analytical instruments, and the harm of milk purchasing enterprises and consumers.

Inactive Publication Date: 2010-12-01
BEIJING ZHIYUNDA TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Before the melamine incident, the purchase method of fresh milk has been continued to use the original method in the past, that is, the density, sensory, and acidity are used as purchase criteria. Milk is mixed with water to achieve the purpose of illegal profit, causing harm to milk purchasing companies and consumers
[0005] At present, there are various analytical instruments for detecting urea in liquid milk on the market. Large-scale instruments are expensive and can only be used in laboratories. The cost of new desktop and portable analytical instruments is relatively high, and ordinary people cannot afford them.

Method used

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  • Test paper for quickly detecting urea in liquid milk and preparation method thereof
  • Test paper for quickly detecting urea in liquid milk and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0091] The production process of the first test paper block of the present invention is: weigh the reagents one by one according to the formula order of the first reagent, and dissolve them one by one, and place them in the immersion tray for use; filter paper (model: 3MM) that has been cut Soak in the middle of the solution, hang it in an oven, and dry it at 60°C for 25 minutes. Paste the treated filter paper on the substrate, cut it into strips with a length of 8cm and a width of 1cm, and store in a sealed and dry environment at 2-30°C. Do not put it in the refrigerator or expose it to direct sunlight.

Embodiment 2

[0093] Liquid milk samples purchased from supermarkets were tested to contain no urea. Take an appropriate amount of sample in a clean and dry container, and take it as the standard to be able to cover the test area of ​​the test paper; immerse the test area of ​​the test paper into the sample to be tested, and take it out immediately; place the reagent block of the test paper horizontally and compare it with the color chart, within 30 seconds Read semi-quantitative test results in-line. As a result, the urea content was judged to be 0.

[0094] Add urea at a concentration of 0.5g / kg to the urea-free liquid milk sample, and test according to the above steps, and the value judged by the result is consistent with the actual amount added.

Embodiment 3

[0096] 10 liquid milk samples sold in the market were tested with urea rapid detection test paper, and the results were judged, 9 of which were normal liquid milk, and 1 was added with urea. The above 10 samples were all verified by the measurement of the instrument.

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Abstract

The invention discloses a test paper for quickly detecting urea in liquid milk and a preparation method thereof, and belongs to the field of chemical detection. The test paper consists of a detection substrate and a detection test paper. The test paper adopts the detection principle that: paradime thylaminobenzaldehyde is reacted with the urea to generate paradime thylaminobenzaldehyde urea under an acid condition, and the product is a lemon yellow compound. The method for quickly detecting the urea in the liquid milk has the advantages of quickness, sensitivity, simple and convenient operation and low cost, does not need a professional to operate, is convenient for common people to use at home, and also can be used for quick detection of industry and commerce, food safety and markets.

Description

technical field [0001] The invention relates to a fast, sensitive and convenient test paper for detecting urea in liquid milk and a preparation method thereof, belonging to the field of chemical detection. Background technique [0002] After the melamine incident, the dairy industry was greatly shaken, and urea testing was paid more and more attention. Urea is a product of protein metabolism and exists in small amounts in mammalian milk. However, in order to seek personal gain, individual criminals mix urea, the most common nitrogen fertilizer, into milk to increase its nitrogen content, which seriously damages the health of consumers, especially infants and young children. [0003] Urea is a colorless and odorless crystal that is easily soluble in water and liquid milk. It has no effect on the color of milk when mixed into milk, and can increase the concentration of milk without much change in sense and taste. It is the substance of choice for adulteration by dairy farmer...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N21/78
Inventor 桑华春韩丹丹
Owner BEIJING ZHIYUNDA TECH CO LTD
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