Hanging white block - formaldehyde rapid test kit instruction manual

Product number: YP-03

1. Method principle

Hanging white block decomposes into formaldehyde, sodium bisulfite and sulfur dioxide in food. Formaldehyde reacts with AHMT to form a purple compound, and the formaldehyde content is obtained by comparing it with a colorimetric card. When a positive result occurs, then determine whether the sample contains hanging white block by measuring the content of sulfur dioxide in the sample.

2. Scope of application

This kit is suitable for the rapid screening of hanging white block in rice noodle products and yuba, tremella, day lily, wolfberry and other foods.

3, you need to bring your own tools

scissors, balance (0.1-100 g), purified water, ultrasonic wave, timer

4, sample determination

1, weighed shredded or minced (wolfberry sample is not minced or shredded) 1 gram of the sample in the sample cup, add pure water to 10 ml scale, mix well, soak for 10 minutes.

* Samples with strong water absorption, such as Tremella, take 0.2 grams in the sample cup, add pure water to 10 ml scale, mix well, soak for 10 minutes.

2, with a straw to take 1 ml of the soaking liquid in the test tube, add 6 drops of reagent A, 6 drops of reagent B, mix well, ultrasound for 2 minutes (or stand for 10 minutes), add 4 drops of reagent C, mix well and compare with the colorimetric card, calculate the formaldehyde content of the decomposition of the hanging white block in the sample.

Sampling amount of 0.2 grams of sample content = the corresponding concentration value on the colorimetric card 5.

Five, detection limit

The hanging white block of this kit - formaldehyde detection limit is 2.5 mg/kg.

Six, precautions

1, some foods contain trace formaldehyde background value, such as vermicelli is about 1 mg/kg, yuba about 4-6 mg/kg, should pay attention to distinguish.

2, if there is a positive result, the content of sulfur dioxide should be tested again. If the content of sulfur dioxide also exceeds the standard, the sample may contain white block components, and the sample can be sent for inspection to further determine.

Seven, storage conditions and product valid period

1, storage conditions: store in a cool, dry and dark place;

2, product valid period: 12 months.

8. Kit composition

Serial number

Specifications

Composition

10 times/box

20 times/box

50 times/box

100 times/box

1

reagent A

1 bottle

1 bottle

1 bottle

2 bottle

2

reagent B

1 bottle

1 bottle

1 bottle

1 bottle

2 bottle

3

reagent C

1 bottle

1 bottle

1 bottle

1 bottle

2 bottle

4

graduated sample cup (recyclable)

1

1

1

1

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