Kit for semi-quantitative detection of urea in food and preparation method of test paper

Abstract

The invention discloses a kit for semi-quantitative detection of urea in food and a preparation method of test paper, the kit comprises the test paper and a colorimetric card, the test paper comprises a detection area, the detection area is provided with a base layer and a detection composition attached to the base layer, and the detection composition is attached to the base layer by dispersing a solution of the detection composition on the base layer. The detection composition comprises urease, a surfactant and an indicator, in the base layer, the content of the urease is 0.10-0.40 mg / cm <2>, and the content of the indicator is 0.03-4.32 mg / cm <2>; wherein the surface active agent is triton X-100 or tween-80, the content of the triton X-100 in the base layer is 0.22 mg / cm <2> to 2.16 mg / cm <2>, and the content of the tween-80 in the base layer is 1.67 mg / cm <2> to 16.7 mg / cm <2>. According to the invention, the test paper for urea detection and the preparation method of the test paper can be provided, wherein the test paper can be used for carrying out rapid, convenient, high-sensitivity and high-accuracy semi-quantitative analysis detection on a to-be-detected sample.

Description

technical field [0001] The present disclosure generally relates to the field of chemical detection, in particular to a kit for semi-quantitative detection of urea in food and a method for preparing test paper. Background technique [0002] Urea is the final product of amino acid metabolism. It is synthesized in the liver and can be freely filtered out from the glomerulus. 40%-50% is passively reabsorbed in the medulla of the glomerulus. However, when the urea content in the human body exceeds its own After the absorption capacity, it will cause harm to the liver, kidney, alveoli, etc. of the human body. The reply letter of the General Office of the Ministry of Health on the "Usage Standards of Food Additives" (GB2760-2011) clearly pointed out that urea lacks the necessity of food additive technology and should not be used as a food processing aid for production, operation and use. There are endless problems with urea, such as increasing the protein content of dairy products...

AI Technical Summary

Problems solved by technology

[0004] But all there is certain limitation in above-mentioned method, the sensitivity of p-dimethylaminobenzaldehyde (PDAB) colorimetric method is not high, and will strictly control the add-on of chromogenic agent in the operation process, is unfavorable for operation

The reagents required by the enzyme coupling method are expensive and unstable after dissolution, so it needs to be tested with a UV spectrophotometer

The cresol red method can develop color only in alkaline environment, while urease generally has the best activity in acidic environment, and the activity of urease is not high or even inactivated in alkaline condition, resulting in high detection error rate

[0005] Therefore, some of the above methods need the help of laboratory instruments, some have low sensitivity, and some have high cost of raw materials. They are not suitable for large-scale rapid detection on site, and are not suitable for ordinary home self-test. Requirements for simple, fast and portable testing

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