Fluorescein is a fluorescent compound that emits green light when exposed to ultraviolet radiation. It is commonly used in medical diagnostics to detect corneal abrasions and in environmental monitoring.
| IUPAC Name | 3H-xanthen-3-one, fluorescein |
| Molecular Formula | C20H12O5 |
| CAS Number | 2321-07-5 |
| Synonyms | C.I. 45350; Uranin; D and C yellow no. 7; Fluoresceine; Resorcinolphthalein; Solvent yellow 94; 3′,6′-dihydroxyfluoran; NSC 29321 |
| InChI | InChI=1S/C20H12O5/c21-15-9-5-12(6-10-15)18-14(20(24)25)4-8-17(23)19(18)13-3-1-2-11(7-13)16(22)C20H12O5/c21-15-9-5-12(6-10-15)18-14(20(24)25)4-8-17(23)19(18)13-3-1-2-11(7-13)16(22)23/h1-10,22-23H,(H,24,25) |
Fluorescein Molar Mass
Fluorescein has a molar mass of 332.31 g/mol. Molar mass is the mass of one mole of a substance, and it is expressed in grams per mole. Fluorescein’s molar mass is calculated by adding up the atomic masses of all the atoms in one molecule of fluorescein. Fluorescein’s molar mass is important in many aspects of its applications, including medical diagnostics and environmental monitoring.
Fluorescein Boiling Point
The boiling point of fluorescein is not well defined because it decomposes before it reaches its boiling point. However, fluorescein can be sublimed at a temperature of approximately 340 °C. Sublimation is the process by which a solid turn into a gas without passing through a liquid phase. In some cases, sublimation is used to purify solids or to create thin films.
Fluorescein Melting Point
Fluorescein has a melting point of 314-317 °C. Melting point is the temperature at which a solid turns into a liquid. The melting point of fluorescein is important in many applications, including medical diagnostics, environmental monitoring, and material science. The melting point of fluorescein can be affected by impurities, pressure, and other factors.
Fluoresceine Density g/mL
The density of fluoresceine is 1.92 g/mL. Density is a measure of how much mass is contained in a given volume of a substance. The density of fluoresceine is important in many applications, including medical diagnostics, environmental monitoring, and material science. The density of fluoresceine can be affected by temperature, pressure, and other factors.
Fluoresceine Molecular Weight
Fluoresceine’s molecular weight is 332.31 g/mol. Molecular weight is the mass of one molecule of a substance, and it is expressed in grams per mole. Fluoresceine’s molecular weight is important in many aspects of its applications, including medical diagnostics and environmental monitoring.
Fluoresceine Structure
Fluoresceine has a complex structure that includes two aromatic rings connected by a carbon chain. It has a hydroxyl group on one of the rings and a carboxylic acid group on the other. Fluoresceine’s structure is important in many applications, including medical diagnostics, environmental monitoring, and material science. The structure of fluoresceine affects its physical and chemical properties, including its fluorescence.
Fluoresceine Formula
The molecular formula of fluoresceine is C20H12O5. The formula shows the number and types of atoms present in one molecule of fluoresceine. The formula is important in many aspects of fluoresceine’s applications, including medical diagnostics and environmental monitoring. The formula can be used to calculate the molar mass and molecular weight of fluoresceine.
| Appearance | Bright yellow or yellow-green crystalline powder |
| Specific Gravity | 1.92 g/cm3 |
| Color | Yellow-green |
| Odor | Odorless |
| Molar Mass | 332.31 g/mol |
| Density | 1.92 g/mL |
| Melting Point | 314-317 °C |
| Boiling Point | Decomposes before boiling |
| Flash Point | Not applicable |
| Water Solubility | 0.08 g/L |
| Solubility | Soluble in ethanol, ether, acetone, and other organic solvents |
| Vapour Pressure | Not applicable |
| Vapour Density | Not applicable |
| pKa | 3.2 (first dissociation) and 4.4 (second dissociation) |
| pH | 7.4 (at a concentration of 0.1%) |
Fluoresceine Safety and Hazards
Fluoresceine is generally considered safe to use in medical diagnostics and other applications. However, it can cause eye and skin irritation, and inhalation of the powder may cause respiratory irritation. Ingestion of large amounts of fluoresceine may cause gastrointestinal irritation and vomiting. It is important to handle fluoresceine with care and to use appropriate protective equipment, such as gloves and eye protection. In case of contact with skin or eyes, the affected area should be washed thoroughly with water. Any ingestion or inhalation of fluoresceine should be treated as a medical emergency, and immediate medical attention should be sought.
| Hazard Symbols | None |
| Safety Description | Keep away from heat, sparks, and flame. Avoid inhalation, ingestion, and contact with skin and eyes. |
| UN IDs | UN2811 |
| HS Code | 3204.19.90 |
| Hazard Class | 6.1 |
| Packing Group | III |
| Toxicity | Fluoresceine has a low level of toxicity and is not considered to be a significant health hazard. It is not classified as a carcinogen, mutagen, or reproductive toxin. However, it can cause irritation to the skin, eyes, and respiratory system. Ingestion of large amounts may cause gastrointestinal irritation and vomiting. |
Fluoresceine Synthesis Methods
There are several methods for synthesizing fluoresceine, but the most common one involves the reaction between phthalic anhydride and resorcinol in the presence of a strong acid catalyst, such as sulfuric acid. The reaction proceeds through a series of intermediate steps, leading to the formation of fluoresceine.
Another method involves the reaction between phthalic anhydride and resorcinol in the presence of a base catalyst, such as sodium hydroxide. The acid-catalyzed method is used more than this.
In addition to these methods, there are also several modified procedures for synthesizing fluoresceine. Using microwave irradiation can decrease the reaction time and enhance the product yield. Another modification involves using ionic liquids as the solvent for the reaction, which can improve the selectivity of the reaction and reduce the amount of waste generated.
Regardless of the method used, the synthesis of fluoresceine requires careful control of reaction conditions, such as temperature, concentration, and reaction time, to ensure high yield and purity of the product. The resulting fluoresceine can be purified through recrystallization or column chromatography, depending on the desired level of purity.
Fluorescein Uses
Due to its fluorescent properties, fluorescein finds versatile usage in various applications. Some of its common uses are:
- Medical diagnostics: Used in ophthalmology to diagnose corneal abrasions, foreign bodies, and other eye conditions. Used in angiography to visualize blood vessels and in dermatology to diagnose skin conditions.
- Fluorescent microscopy: Used as a fluorescent stain in microscopy to label and visualize biological molecules and structures, such as proteins, nucleic acids, and membranes.
- Biochemistry: Used as a probe to study biochemical processes, such as enzyme activity and ligand binding. Used as a pH indicator.
- Water tracing: Used as a tracer in hydrology to study water movement and flow patterns in rivers, lakes, and groundwater.
- Quality control: Used as a fluorescent dye in quality control and testing of products, such as soaps, detergents, and textiles.
- Art and entertainment: Used as a fluorescent pigment in art and entertainment to create neon and blacklight effects.
Overall, the fluorescent properties of fluorescein make it a valuable tool in a wide range of applications, from medical diagnostics to scientific research and beyond.
Questions:
Q: What is fluorescein angiography?
A: Fluorescein angiography is a medical imaging technique used to visualize blood vessels in the eye. It involves injecting a fluorescent dye, such as fluorescein, into a vein in the arm and then taking photographs of the eye as the dye circulates through the blood vessels.
Q: What is fluorescein stain?
A: Fluorescein stain is a medical diagnostic tool used to detect corneal abrasions and other eye injuries. It involves placing a few drops of a fluorescein solution onto the eye, which then binds to damaged cells and becomes visible under blue light.
Q: What is fluorescein dye?
A: In medical and scientific applications, researchers commonly use fluorescein dye to label and visualize biological molecules and structures such as proteins, nucleic acids, and membranes due to its fluorescent properties.
Q: What is fluorescein eye stain?
A: Fluorescein eye stain is a medical diagnostic tool used to detect corneal abrasions and other eye injuries. It involves placing a few drops of a fluorescein solution onto the eye, which then binds to damaged cells and becomes visible under blue light.
Q: Where can I buy fluorescein powder?
A: Fluorescein powder can be purchased from a variety of chemical suppliers, both online and in-person. It is important to ensure that the supplier is reputable and that the product is of high purity and quality. Some examples of chemical suppliers that offer fluorescein powder include Sigma-Aldrich, Fisher Scientific, and Alfa Aesar.