Product Overview

Boric Acid 99.5% AR/ACS (CAS No. 10043-35-3) is analytical-reagent orthoboric acid. Its weak-acid behaviour results mainly from the acceptance of hydroxide to form tetrahydroxyborate, while complex formation with mannitol, sorbitol and related polyols increases its apparent acidity. This complexation provides the chemical basis for well-defined titrimetric procedures involving boric acid and boron-containing samples.

The AR/ACS grade is intended for precise analytical work of a general nature, including reagent-solution preparation, buffer preparation and conventional quantitative procedures requiring ACS-defined reagent characteristics. The grade designation does not automatically confer certified-reference-material status, primary-standard status or metrological traceability.

Typical Applications

• Preparation of boric acid–borate buffer solutions for analytical and wet-chemical procedures.
• Titrimetric determination or assay of boric acid using mannitol, sorbitol or another suitable polyol.
• Preparation of boric acid receiver solutions for ammonia collection in Kjeldahl nitrogen determinations.
• Preparation of analytical reagent solutions, blanks and controls for laboratory quality-control work.
• Investigation of boric acid–borate equilibria and polyol complexation in analytical method development.

Common Synonyms

• Orthoboric acid
• Boracic acid
• Boron trihydroxide
• Trihydroxyborane
• Boric acid

Storage Conditions

Store in a tightly closed container in a clean, dry area and protect from moisture and laboratory contamination. Close the container promptly after sampling to preserve reagent cleanliness and minimise contamination that could affect analytical solutions or blanks.