Fluorescein 200% ( resorcinolphthalein ) UV DYE Pure Compound - 100g

Fluorescein 200% (Resorcinolphthalein)
Other Names: Fluorescein sodium (when in salt form), 3',6'-Dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one
Chemical Formula: C₂₀H₁₂O₅
Molar Mass: 332.31 g/mol
CAS Number: 2321-07-5 (free acid form)
Appearance: Orange-red to dark red powder
Purity: Pure compound (technical grade, UV dye content ~200%)

Fluorescein is a synthetic organic compound from the xanthene dye group. It exhibits strong fluorescence and is used extensively as a tracer dye and UV-reactive marker in industrial and analytical contexts. In its pure acid form, it appears dark red under visible light and glows bright green under UV illumination (excitation ~490 nm, emission ~515 nm).

Chemical and Physical Properties

• Density: ~1.6 g/cm³

• Melting Point: ~314 °C (with decomposition)

• Solubility in Water: Low (as free acid); forms water-soluble salts

• Solubility in Solvents: Soluble in alcohol, alkali solutions, and polar organic solvents

• Fluorescence: Intense green fluorescence under UV or blue light

• Stability: Stable under normal conditions, light-sensitive

Applications

UV and Fluorescent Tracing

• Used as a fluorescent tracer in leak detection, flow studies, and hydraulic modeling in pipelines and open water systems.

Industrial Dyeing

• Applied in quality control, UV detection systems, and marker dyes for inks and coatings.

Analytical Chemistry

• Employed as a pH-sensitive indicator and in fluorometric titrations.

Research and Laboratory Use

• Utilized in imaging techniques and to label or visualize fluid movements under UV light.

Safety

Signal Word: Warning

Hazard Statements:

• H315: Causes skin irritation

• H319: Causes serious eye irritation

• H335: May cause respiratory irritation

Precautionary Statements:

• P261: Avoid breathing dust

• P264: Wash hands thoroughly after handling

• P271: Use only outdoors or in a well-ventilated area

• P280: Wear protective gloves, protective clothing, and eye protection

• P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing

• P337+P313: If eye irritation persists: Get medical advice/attention

Handling and Storage

• Handling: Avoid generation of dust. Use in well-ventilated or filtered-air environments. Wear suitable protective clothing and avoid contact with skin and eyes.

• Storage: Store in a cool, dry, and dark container, tightly sealed. Protect from direct sunlight and moisture.

• Incompatibilities: Strong oxidizing agents, acids

Environmental Considerations

Although fluorescein is used in environmental tracing, concentrated discharge into aquatic environments should be minimized. Follow local regulations regarding disposal of dye-containing solutions.