Application of diazo p-nitroaniline_Kain Industrial Additive

Background and overview^[1]

Diazo-p-nitroaniline can be used as a dye. If diazo-p-nitroaniline is inhaled, please move the patient to fresh air; if skin contact occurs, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical treatment if you feel uncomfortable; if contact with eyes, remove The eyelids should be separated, rinsed with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.

Apply^[1]

Diazo-p-nitroaniline is mainly used as a color developer. For example, it can be used for rapid screening of phenolic estrogens in cosmetics. Estrogen has been illegally added to various functional cosmetics. Long-term use of estrogen can lead to pigmentation, skin atrophy and thinning, precocious puberty in children, feminization of men, and even various cancers, seriously threatening human health. It has been banned by the 2007 " "Hygienic Specifications for Cosmetics" stipulates that they are prohibited substances, and their detection is of great significance to strictly control the quality of cosmetic products, ensure the safety of cosmetics use, and is of great significance to the government's health supervision and protection of people's health. At present, the detection methods of estrogen in cosmetics are mainly high performance liquid chromatography and gas chromatography-mass spectrometry. There is still a lack of simple and rapid sanitary chemical testing methods for rapid on-site screening. Although the color development method using chemical developers is fast, due to the complex ingredients in cosmetics, direct use of chemical developers for color development will cause false positive reactions. When using diazobenzenesulfonic acid test solution, a commonly used color developer for phenolic estrogens, for color development, phenolic substances in cosmetics will interfere significantly with it. In particular, the preservative salicylic acid present in cosmetics can produce false positive reactions when using diazobenzenesulfonic acid test solution for color development, which cannot be eliminated and needs to be further confirmed by high-performance liquid chromatography. Therefore, this limits the application of chemical chromogenic methods for rapid screening of phenolic estrogens in cosmetics. Some studies provide a rapid screening method for phenolic estrogens in cosmetics, which includes the following steps: S1. Add saturated weak alkaline solution to the cosmetics and shake thoroughly; then add chloroform and shake thoroughly; S2. Absorb The chloroform layer solution reacts with the color developer and determines whether the cosmetics contain phenolic estrogens based on the color reaction. The chromogen is diazo-p-nitroaniline, and the diazo-p-nitroaniline test solution is prepared by the following method: add 6 mol/L hydrochloric acid to p-nitroaniline and dissolve it with ultrasound to obtain p-nitroaniline. Hydrochloric acid solution; mix crushed ice and sodium nitrite solution, and add the hydrochloric acid solution of p-nitroaniline described in S1 under stirring; that is, the chromogenic reagent test solution is obtained; wherein, the p-nitroaniline, hydrochloric acid , the dosage ratio of crushed ice and sodium nitrite solution is 0.5~1.5g: 2~4mL: 20~40g: 4~8mL; the concentration of the sodium nitrite solution is 0.5~1.5 mol·L^-1.

Preparation^[1]

Preparation of diazo-p-nitroaniline test solution: S1. Put 0.9g of p-nitroaniline in a 50mL beaker, then add 3mL of 6mol/L hydrochloric acid, stir ultrasonically to dissolve the hydrochloric acid solution of p-nitroaniline; S2. Mix 30g of crushed ice and 6.5mL of 1mol·L^-1 sodium nitrite solution in another 50mL beaker, and pour into the hydrochloric acid solution of p-nitroaniline while stirring. Continue to stir the reactant for 5 minutes to obtain the chromogenic reagent test solution. Test solutions are stored in brown bottles.