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Patent Blue V is used in laboratory staining and analytical applications due to its ability to bind to certain biological materials.
Patent Blue V is a dye used in lymphangiography and sentinel node biopsy in medicine to colour lymph vessels.
Patent Blue V is also used as a stain in dental disclosing tablets to reveal dental plaque on teeth.
CAS Number: 3536-49-0
EC Number: 222-573-8
Molecular Formula: C₂₇H₃₁N₂NaO₆S₂
Molecular Weight: 566.66 g/mol
SYNONYMS:
Patent Blue V,E131,CI 42051,Acid Blue 3,Food Blue 5,Sulfan Blue,Disodium salt of Patent Blue V,Blue V,Lymphazurin (in medical context),Food Blue 5,Sulphan Blue,Acid Blue 3,L-Blau 3,C-Blau 20,Patentblau V,Sky Blue,C.I. 42051,E 131,Patent Blue,Patent Blue V,Ethanaminium, N-[4-[4-(diethylamino)phenyl, methylene]-2,5-cyclohexadien-1-ylidene]-N-ethyl-, inner salt, sodium salt (1:1),C.I. Acid Blue 3, monosodium salt (8CI),Ethanaminium, N-[4-[4-(diethylamino)phenyl, methylene]-2,5-cyclohexadien-1-ylidene]-N-ethyl-, hydroxide, inner salt, monosodium salt,Ethanaminium, N-[4-[4-(diethylamino)phenyl, methylene]-2,5-cyclohexadien-1-ylidene]-N-ethyl-, inner salt, monosodium salt (9CI),C.I. 42051:2,C.I. Food Blue 5:2,Food Blue 5:2,Patent Blue V Sodium Salt,N-[4-[4-(Diethylamino)phenyl,
methylene]-2,5-cyclohexadien-1-ylidene]-N-ethylethanaminium monosodium salt,Acid Blue 3 monosodium salt,
Patent Blue V, also known as E131, is a synthetic dye commonly used for its vibrant light blue color.
Patent Blue V can be used alone or in combination with other dyes in a wide range of products, both in food and medical products.
Patent Blue V appears as a dark blue or green powder with the molecular formula C54H62CaN4O14S4.
Patent Blue V is highly soluble in water and forms a blue solution, which is used for coloring purposes.
Despite its widespread use, Patent Blue V has been the subject of extensive analysis regarding food safety and its use as a dye.
Patent Blue V, also called Food Blue 5, Sulfan Blue, Acid Blue 3, L-Blau 3, C-Blau 20, Patentblau V, Sky Blue or CI 42051, is a dark bluish synthetic triphenylmethane dye used as a food coloring.
Patent Blue V's E number as a food additive is E131.
Patent Blue V is the sodium or calcium salt of [4-( -(4-diethylaminophenyl)-5-hydroxy- 2,4-disulfophenylmethylidene)-2,{16}}cyclohexadiene-1-ylidene] diethylammonium hydroxide internal salt.
The color of Patent Blue V is pH dependent.
In aqueous solution, Patent Blue V's color will change from dark blue in alkaline or weakly acidic environments.
In stronger acidic conditions, Patent Blue V will be medium to yellow-orange.
Patent Blue V is useful as a pH indicator for the range of 0.8–3.0.
The structure of Patent Blue V is also redox sensitive and changes from the reduced yellow form to the oxidized red form in solution.
Patent Blue V's reduction potential of approximately 0.77 volts is similar to that of other triphenylmethane dyes.
Patent Blue V can be used as a reversible redox indicator in some analytical methods.
Patent Blue V was included in Salter Science's chemistry kits under the name Sky Blue in the 1970s and 80s due to its pH-dependent color.
Patent Blue V, also called Food Blue 5, Sulphan Blue, Acid Blue 3, L-Blau 3, C-Blau 20, Patentblau V, Sky Blue, or C.I. 42051, is a sky blue synthetic triphenylmethane dye used as a food coloring.
As a food additive, Patent Blue V has E number E131.
Patent Blue V is a sodium or calcium salt of [4-(α-(4-diethylaminophenyl)-5-hydroxy- 2,4-disulfophenylmethylidene)-2,5-cyclohexadien-1-ylidene] diethylammonium hydroxide inner salt.
Patent Blue V is a sulfonated dye designed for high solubility and strong coloration in aqueous systems.
Structurally related to other triphenylmethane dyes, Patent Blue V contains sulfonic acid groups that enhance its water solubility and facilitate its use in a variety of applications.
Patent Blue V is especially recognized for its use in food coloring and as a diagnostic dye in medical procedures.
The color of the dye, Patent Blue V, is pH-dependent.
In aqueous solution, Patent Blue V's color will vary from a deep blue in alkaline or weakly acidic medium to a yellow–orange in stronger acidic conditions.
Patent Blue V is useful as a pH indicator for the range 0.8–3.0.
The structure of Patent Blue V is also redox-sensitive, changing from a reduced yellow form to an oxidized red form in solution.
The reduction potential of around 0.77 volts is similar to that of other triphenylmethane dyes.
Patent Blue V is usable as a reversible redox indicator in some analytical methods.
Because of its pH-dependent color, Patent Blue V was included in chemistry sets from Salter Science in the 1970s and 80s under the name Sky Blue.
Patent Blue V (E131) is a dark blue synthetic triphenylmethane dye used as a food coloring (E131) and in medical diagnostics for lymphangiography and sentinel node biopsy.
Patent blue V is a triarylmethane dye that occurs as a blue powder or granules.
Patent Blue V is principally the calcium or sodium salt of 2-[4-[alpha-(4-diethyl-aminophenyl)-5-hydroxy-2,4-disulfonatophenylmethylidene]-2,5-cyclohexadien-1-ylidene] diethylammonium hydroxide inner salt, and subsidiary coloring matters.
Patent Blue V may be converted to the corresponding aluminum lake.
Patent Blue V is also known by the name of Sulphan Blue, Acid Blue 3, Food Blue 5, and comprises dark bluish synthetic dye that finds use as food coloring and food additive.
With appearance of violet powder, Patent Blue V comes in varying colors depending on pH value of medium (deep blue in basic medium and yellowish-green in acidic medium).
Patent Blue V, often also called “Sulfanilamide Patent Blue,” is an artificial coloring agent.
Patent Blue V typically has a bright blue color.
Patent Blue V is available as a powder that dissolves well in aqueous solutions and is used to color foods.
Patent Blue V or Acid Blue 3 is a synthetic triphenylmethane dye.
Patent Blue V occurs as dark blue powder or granules.
Patent Blue V is principally the calcium or sodium salt of 2-[4-[alpha-(4-diethyl-aminophenyl)-5-hydroxy-2,4-disulfonatophenylmethylidene]-2,5-cyclohexadien-1-ylidene] diethylammonium hydroxide inner salt, and subsidiary colouring matters.
USES and APPLICATIONS of PATENT BLUE V:
Patent Blue V is widely used in the food industry as a coloring agent in products such as beverages, confectionery, desserts, and processed foods, particularly within regions where its use is permitted.
In medicine, Patent Blue V is commonly used as a diagnostic dye, especially in procedures like sentinel lymph node mapping, where it helps visualize lymphatic vessels and nodes.
This application is critical in cancer diagnostics and surgical procedures.
In pharmaceuticals, Patent Blue V is used to color tablets, capsules, and topical formulations.
In cosmetics, Patent Blue V may be used in products like mouthwashes and personal care items.
Additionally, Patent Blue V is used in laboratory staining and analytical applications due to its ability to bind to certain biological materials.
Patent Blue V is a dye used in lymphangiography and sentinel node biopsy in medicine to colour lymph vessels.
Patent Blue V is also used as a stain in dental disclosing tablets to reveal dental plaque on teeth.
Patent Blue V is useful as a pH indicator for the range 0.8–3.0.
Patent Blue V is usable as a reversible redox indicator in some analytical methods.
Patent Blue V is not commonly used, but in Europe it can be found in Scottish eggs, some jelly desserts, blue Curaçao, some types of jelly (though not in genuine Jell-O branded products), among others.
A significant advantage is the very deep color Patent Blue V produces even at low concentrations.
A disadvantage is that Patent Blue V fades quite quickly when exposed to light.
In medicine, Patent Blue V is used as a dye to color lymphatic vessels in lymphangiography and sentinel node biopsy.
Patent Blue V is also used as a stain in dental clarification tablets to show dental plaque on teeth.
Sweets and Confectionery: Various sweets, candies, and jellies are colored blue with Patent Blue V.
Beverages: Some fruit juices, carbonated drinks, and other beverages can be colored with Patent Blue V.
Frozen Products: Patent Blue V can be used in ice cream, frozen desserts, and other frozen products.
Pharmaceuticals: Patent Blue V is also used in the coating and coloring processes of some pharmaceuticals.
Patent Blue V is commonly used in the food industry to give various products a blue color.
In medicine, Patent Blue V is used in lymphangiography and sentinel node biopsy as a dye to color lymph vessels.
Patent Blue V is also used in dental disclosing tablets as a stain to show dental plaque on teeth.
Medical Use: Patent Blue V is used to map lymph nodes or vessels, appearing as a bright blue dye.
Patent Blue V is stable under light and heat, often used in food and cosmetics.
Common Uses of Patent Blue V: Typical applications include beverages, confectionery, bakery, dairy fats and oils, meat, seafood, snacks, dry mixes and seasonings, fruit preparation, and convenient foods.
Patent Blue V is also called Food Blue 5, Sulphan Blue, Acid Blue 3, L-Blau 3, C-Blau 20, Patentblau V, or Sky Blue C.I. 42051.
Patent Blue V is used as a food additive in certain jelly sweets and gelatin desserts in Europe.
In medicine, Patent Blue V finds usage in lymphangiography as well as in sentinel node biopsy as dye to color lymph vessels so that these can further be injected with X-ray contrast medium.
Patent Blue V is an artificial coloring agent widely used in the food industry.
-Patent Blue V is used as dye:
Patent Blue V is not widely used, but in Europe it can be found in Scotch eggs, certain jelly sweets, blue Curaçao, and certain gelatin desserts, among others.
An important advantage is the very deep color Patent Blue V produces even at low concentration.
A disadvantage is that Patent Blue V fades fairly quickly when exposed to light.
BENEFITS of PATENT BLUE V:
One of the primary benefits of Patent Blue V is its strong and stable coloration in aqueous environments, which makes it efficient and cost-effective.
Patent Blue V's high solubility allows easy incorporation into liquid formulations.
Its visibility and contrast make Patent Blue V particularly valuable in medical diagnostics, where precise visualization is required.
Patent Blue V also offers versatility across multiple industries, including food, pharmaceuticals, and cosmetics.
PHYSICAL AND CHEMICAL PROPERTIES of PATENT BLUE V:
Patent Blue V typically appears as a dark blue to violet powder or granules.
Patent Blue V is highly soluble in water, forming a bright blue solution, and is only slightly soluble in alcohol while being practically insoluble in nonpolar organic solvents.
The aqueous solutions exhibit strong absorption in the visible spectrum, generally around 635–640 nm, giving rise to Patent Blue V's intense blue color.
Chemically, Patent Blue V is relatively stable under normal storage and usage conditions, particularly in neutral or mildly acidic environments.
However, Patent Blue V may undergo degradation when exposed to strong oxidizing agents, prolonged light exposure, or elevated temperatures.
Like many dyes in its class, Patent Blue V decomposes upon heating rather than exhibiting a clear melting point.
The presence of sulfonate groups makes Patent Blue V an anionic dye, which enhances its interaction with polar media and biological tissues.
Patent Blue V's pH stability is moderate, but extreme alkaline conditions may lead to color changes or degradation.
CHARACTERISTICS of PATENT BLUE V:
Patent Blue V is characterized by its high tinctorial strength, allowing it to impart strong coloration at relatively low concentrations.
Patent Blue V provides a deep, vivid blue shade and is often used alone or blended with other dyes to achieve specific hues.
Patent Blue V has good dispersibility in aqueous systems and moderate resistance to light and heat, although prolonged exposure to harsh conditions may reduce its color intensity.
Its affinity for biological tissues also makes Patent Blue V useful in diagnostic and staining applications.
CHEMICAL PROFILE of PATENT BLUE V:
Formula:
Calcium or sodium salt of 2-[(4-diethylaminophenyl)(4-diethylimino-2, 5-cyclohexadien-1-ylidene)methyl]-4-hydroxy-1,5-benzenedisulfonate.
Appearance:
Patent Blue V is blue powder or granules.
Solubility:
Patent Blue V is soluble in water, alcohol, and glycerol.
Applications
Food Industry:
Patent Blue V is used in decorations, coatings, and specialized foodstuffs.
Medical Field:
Patent Blue V is used as a surgical dye for sentinel lymph node identification.
Other Uses:
Patent Blue V is sometimes used in cosmetics, textile, and as a laboratory pH indicator.
PHYSICAL and CHEMICAL PROPERTIES of PATENT BLUE V:
Chemical name: Patent Blue V
Other names: E131, Sulphan Blue, Acid Blue 3, Food Blue 5
Chemical class: Triphenylmethane dye (sulfonated dye)
Molecular formula: C₂₇H₃₁N₂NaO₆S₂ (commonly as sodium salt; variations exist depending on form)
Molar mass: ~560–570 g/mol (depends on salt form)
Appearance: Dark blue to violet crystalline powder
Odor: Odorless
Solubility: Highly soluble in water
Insoluble in most organic solvents (e.g., ethanol, ether)
Absorption maximum (λmax): ~ 635–640 nm (strong blue color in visible spectrum)
Color in solution: Deep blue in neutral and alkaline solutions
State: Solid at room temperature
Stability (physical): Stable under normal storage conditions, especially in dry form
Nature: Strong acidic dye (anionic dye)
Functional groups: Multiple sulfonate (–SO₃⁻) groups → confer high water solubility
Aromatic triphenylmethane core structure
Ionic behavior: Exists mainly as a sodium salt
Dissociates in water to form a negatively charged dye anion
pH behavior: Stable in a wide pH range (approximately pH 3–10)
Color may shift slightly in strongly acidic or alkaline conditions
Redox behavior: Can undergo reduction to leuco (colorless) form under strong reducing conditions
Re-oxidizes back to blue form in air or oxidizing environments
Photostability: Moderately stable under light
Prolonged exposure to strong light may cause gradual fading
Thermal stability: Stable at moderate temperatures
Decomposes at high temperatures (burning/strong heating)
Reactivity: Generally chemically inert under normal conditions
Does not readily react with common food or biological components
Can interact with proteins via ionic interactions (important in biological staining)
Complex formation: Can form weak complexes with proteins and polysaccharides due to ionic nature
CAS Number: 3536-49-0
EC Number: 243-654-4
Calcium salt: 222-573-8
E number: E131 (colours)
Name of Product: Patent Blue V
IUPAC Name: calcium;4-[[4-(diethylamino)phenyl]-(4-diethylazaniumylidenecyclohexa-2,5-dien-1-ylidene)methyl]-6-hydroxybenzene-1,3-disulfonate
Synonyms: Acid Blue 3, C.I. Food Blue 5, Carmine Blue V, Acidal Carmine V, Merantine Blue V
CAS No: 3536-49-0
Molecular Formula: C54H62CaN4O14S4
Molecular Weight: 1159.4 g/mol
Pubchem CID: 77073
Pubchem SID: 463751340
FIRST AID MEASURES of PATENT BLUE V:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation:
Fresh air.
*In case of skin contact:
Take off immediately all contaminated clothing.
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact:
Rinse out with plenty of water.
Call in ophthalmologist.
Remove contact lenses.
*If swallowed:
After swallowing:
Immediately make victim drink water (two glasses at most).
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available
ACCIDENTAL RELEASE MEASURES of PATENT BLUE V:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains.
Collect, bind, and pump off spills.
Observe possible material restrictions.
Take up dry.
Dispose of properly.
Clean up affected area.
FIRE FIGHTING MEASURES of PATENT BLUE V:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2)
Foam
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.
EXPOSURE CONTROLS/PERSONAL PROTECTION of PATENT BLUE V:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection.
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A
-Control of environmental exposure:
Do not let product enter drains.
HANDLING and STORAGE of PATENT BLUE V:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed.
Dry.
STABILITY and REACTIVITY of PATENT BLUE V:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature).
-Possibility of hazardous reactions:
No data available
