Alizarin Yellow GG CAS 584-42-9 IND Indicator pH 10.0 Yellow to 12.0 Brown Acid Base Indicator Mordant Dye

Product Overview

Alizarin Yellow GG, also known as Mordant Yellow 1 (CAS: 584-42-9, MF: C₁₃H₈N₃NaO₅, MW: 309.21), is a sodium salt of an azo dye widely used as an acid–base indicator and biological stain. It appears as a yellow to orange-brown crystalline powder, freely soluble in water (golden-yellow solution) and ethanol, slightly soluble in cold water, acetone and cellosolve, insoluble in most nonpolar organics. In aqueous solution it acts as a pH indicator with transition pH 10.0 (pale yellow / bright yellow) to 12.0 (brown / reddish-brown), making it suitable for strongly alkaline media where common indicators fail. EINECS: 209-536-1 | C.I. Number: 14025.

Key Features & Advantages

• High-Alkaline pH Indicator: Only turns from yellow to brown at pH 10–12, ideal for strong base titrations and high-pH buffer checks.

• Dual Function: Works both as an indicator and as a mordant dye / biological stain (e.g., sperm staining, tissue staining in histology).

• Good Solubility Profile: Readily dissolves in hot water and 25–50% ethanol; commonly supplied as 0.025–0.1% solution in 50% ethanol for lab use.

• Reliable Quality: Available in Indicator (IND), AR, and Biological Stain grades with controlled ignition residue and ethanol solubility test passed.

Main Applications

✔ Acid–base indicator for strong base titrations (pH 10.0 yellow → 12.0 brown)

✔ Biological staining / histology – sperm staining, tissue mordant dye, microscopy

✔ Chromatographic analysis reagent and medium preparation

✔ Textile mordant dyeing (cotton, wool, silk, nylon) when used with metal mordants

✔ Educational labs – demo of azo dye chemistry and high-pH indicator behavior

Storage & Handling

Store in a cool, dry, well-ventilated place in tightly sealed containers. Protect from light (photosensitive azo dye; prolonged light exposure causes fading). Keep away from strong oxidizing agents and strong acids. Non-hazardous for transport per IMDG/IATA (RTECS DH2528550; GHS: Xi, Irritant skin/eye/respiratory; R36/37/38 or H315/H319/H335 under GHS). Use gloves and safety goggles when handling powder.

Safety Summary

• Hazard: Irritant (Xi); may irritate eyes, skin, respiratory tract. Not classified as acutely toxic or environmentally hazardous under normal GHS thresholds, but avoid dust inhalation and ingestion.

• GHS Labeling (typical): Exclamation mark pictogram; H315/H319/H335; P261/P305+P351+P338.

• Intended Use: For laboratory indicator, staining, and industrial mordant applications. Not for food, drug, or cosmetic use unless specified as FCC/USP grade.