The present disclosure provides a continuous process for the synthesis coupled compounds of diazonium salts including azo dyes involving in-situ generation of diazonium salts. It further discloses a set up to carry out the process for the synthesis of coupled compounds of diazonium salts.

The present invention relates to a method for preparing lycopene crystals with high purity and low harm. The method comprises the following steps: (1) mixing lycopene oleoresin with a mixed solvent consisting of an alkane and a lower alcohol, and heating and stirring the resultant for dissolution to form a homogenous solution; (2) cooling the homogenous solution for crystallization, filtering the resultant to obtain a filter cake; and (3) washing the filter cake successively using a lower alcohol and an alkane, and drying the resultant to obtain lycopene crystals. According to the method provided by the present invention, lycopene crystals can be obtained using a mixed solvent by means of one step crystallization, and the crystal content is further improved and harmful substances in the crystals are reduced by means of a two-step crystal washing process to obtain lycopene crystals with high purity and low harm. The method is fast and convenient, lycopene crystals with high purity, low harm, and sanitary safety can be produced, and the method is suitable for industrial production.

The present invention refers to a process for purifying leucoindigo salt solutions, for removal of aromatic amines, particularly aniline and N-methylaniline, comprising: adding to a purification vessel a leucoindigo salt solution containing aromatic amines, said solution in the form of a stationary mass; bubbling with a controlled flow rate an inert gas in the purification vessel, by means of a device submerged at the surface of the stationary mass; injecting with a controlled flow rate a gas purification current into the vessel, by means of a device submerged at the stationary mass; and recovering the purified solution from the vessel. It also refers to the use of inert gas in a process for purifying leucoindigo salt solutions, acting as a gas anti-foaming agent, to reduce foam and chances of product stripping during processing.

A reactive disperse yellow dye is suitable for supercritical CO.sub.2 anhydrous dyeing. The reactive disperse yellow dye in has a parent of azo structure, and has monochlorometriazinyl groups thereon. The reactive disperse yellow dye can be used for supercritical CO.sub.2 anhydrous dyeing of cellulose fiber, protein fiber, chemical fiber and the blended fabrics thereof, and has good dyeing effect particularly for cotton-polyester blended products.

The invention relates to a dyestuff of plant origin, obtained from a colored part of a plant species, the cell tissues of which contain iridisomes responsible for the coloration of said part. It relates most particularly to a blue dyestuff obtained from the arils of the seeds of the plant species Ravenala madagascariensis. It also relates to compositions, in particular cosmetic compositions, especially intended for making up the skin or superficial body growths, containing said dyestuff.

Functionalized fluorescent tracers, compositions, and methods for extracting the functionalized fluorescent tracers from oil phases and other wellbore or drilling fluids are provided. In some implementations, a sorbent for extracting tracer molecules from a fluid includes a silica-based sorbent. The silica-based sorbent includes a hydrophobic functional group and an ionic functional group. In some implementations, the ionic functional group is positively charged. In some implementations, the ionic functional group is negatively charged. A method of extracting a functionalized dye from an oil phase includes mixing a sorbent for extracting tracer molecules with an oil phase sample that includes a functionalized fluorescent tracer, recovering the sorbent from the oil phase, and dispersing the sorbent in an organic solvent. In some implementations, the method includes lowering the pH of the organic solvent. In some implementations, the method includes raising the pH of the organic solvent.

A process for producing the gardenia blue pigment is provided. The process is easy to operate and suitable for industry and the obtained gardenia blue pigment is bright and suitable for industrial application.

The present application provides black perylene pigment microparticles having an average circularity of 0.8 or more which are amorphous; and a method of producing the black perylene pigment microparticles, which comprises a step of mixing a pigment solution in which a black perylene pigment is dissolved and a precipitation solvent for precipitating black perylene pigment microparticles from the pigment solution to form black perylene pigment microparticles, wherein at least one of the pigment solution and the precipitation solvent independently includes a salt of an alkaline earth metal and/or a particle growth inhibitor. The present invention can provide black perylene pigment microparticles having good dispersibility, high concealability and light-shielding property and controlled hue and chroma, and a method of easily producing the same, and the like.

A method of preparing paprika red pigment with low polycyclic aromatic hydrocarbons includes (1) drying, crushing and granulating mature peppers to obtain pepper particles; (2) extracting the pepper particles with a vegetable oil in a rotocel extractor to obtain a paprika red pigment solution; (3) extracting the paprika red pigment solution with an ethanol solution in a liquid-liquid extractor to remove spicy substances; (4) running the paprika red pigment solution through a low-pressure chromatography column to remove polycyclic aromatic hydrocarbons; and (5) concentrating the paprika red pigment solution to obtain the paprika red pigment with low polycyclic aromatic hydrocarbons.

The present invention provides methods of producing decolorized beet products and compositions produced therefrom. In some implementations, the decolorized beet product is decolorized beetroot juice.