Pyrogallic Acid (Pyrogallol) is a white, crystalline, high-purity triphenolic compound with extremely strong reducing properties. It is one of the most powerful organic reducing agents commercially available and rapidly absorbs oxygen from air (turns brown on exposure). Thanks to its three adjacent hydroxyl groups, it exhibits unique reactivity in photography, hair dyes, pharmaceuticals, gas analysis, and specialty chemical synthesis.

 

Technical Specifications

ITEMS SPECIFICATIONS
Industrial Grade CP Grade (chemically pure) AR Level (analytic pure)
Appearance white powder white powder white powder
content ≥99.00% ≥99.50% ≥99.80%
Water Solubility clear and transparent clear and transparent clear and transparent
Melting Point 131-135℃ 132-135℃ 132-135℃
Residue on Ignition ≤0.025% ≤0.02% ≤0.02%
Chloride ≤0.002% ≤0.001% ≤0.001%
Sulfate ≤0.005% ≤0.005% ≤0.005%
Heavy metal ≤5.0 ppm ≤5.0 ppm ≤5.0 ppm

 

Packaging and Storage

  • Packed in cardboard drums, net weight 25 kg per drum.
  • Avoid moisture and light, sealed tightly, no contact with metal.

 

Main Advantages & Unique Properties

  • Extremely strong oxygen scavenger and reducing agent
  • Rapidly develops intense color reactions with metal ions
  • Excellent solubility in water, ethanol, and ether
  • Light-sensitive (used historically in black & white photography)
  • Biologically active – used in antioxidant and enzyme studies
  • Strong chelating ability with iron, molybdenum, and antimony

 

Primary Applications of Pyrogallic Acid

  • Oxygen absorber in gas analysis (Orsat apparatus and micro-respirometry
  • Photographic developer (classic alkaline pyrogallol developer)
  • Hair dye intermediate and color former (oxidative dyes)
  • Anti-oxidant and stabilizer in oils, fuels, and monomers
  • Reagent in analytical chemistry (detection of Fe, Mo, Sb, Ti, V)
  • Pharmaceutical intermediate (synthesis of gallates, trimethoprim)
  • Depilatory agent in leather processing
  • Reducing agent in gold and silver nanoparticle synthesis
  • Laboratory reagent for lignin, tannin, and alkaloid testing

 

Frequently Asked Questions (FAQs)

Is pyrogallic acid the same as gallic acid?
No. Pyrogallic acid (1,2,3-trihydroxybenzene) is the decarboxylated form of gallic acid (3,4,5-trihydroxybenzoic acid). Pyrogallol is much stronger as a reducing agent and oxygen absorber.

Why does pyrogallic acid turn brown when exposed to air?
It rapidly oxidizes in the presence of oxygen and alkalies, forming colored quinones and polymeric humic-like substances.

Can pyrogallic acid still be used in modern photography?
Yes. Pyrogallol developers remain popular among fine-art and large-format photographers for extremely fine grain, high acutance, and unique tonal rendition.

Does pyrogallol work as an oxygen scavenger in boiler water treatment?
Yes, it was historically used, but has largely been replaced by hydrazine, DEHA, and carbohydrazide due to toxicity concerns.

 

Where can I buy high-quality Pyrogallic Acid?

You can contact us via email [email protected] for offers and bulk orders.