Acetonitrile[3]

Updated: 2026-09-13

Overview

Acetonitrile is a nitrile compound derived from acetic acid, serving as one of the simplest organic nitriles. Industrial-grade acetonitrile primarily originates as a byproduct in acrylonitrile manufacturing through the Sohio process. With global production exceeding 100,000 tons annually, it has become an essential solvent for modern chemical industries. This polar aprotic solvent demonstrates unique solvation properties, making it indispensable for chromatographic separations and organic synthesis. The industrial grade typically maintains ≥99% purity, with specialized grades (HPLC, UV) achieving ≥99.9% purity through additional distillation processes.

Physical and Chemical Properties

Acetonitrile's physical characteristics include a relatively low viscosity (0.34 cP at 25°C) and surface tension (29.3 mN/m), facilitating excellent wetting properties. Its high dipole moment (3.92 D) enables dissolution of ionic compounds, while the moderate boiling point allows for easy recovery through distillation. Chemically, acetonitrile exhibits stability under neutral conditions but may hydrolyze slowly in acidic/basic environments. The triple bond between carbon and nitrogen contributes to its reactivity in nucleophilic addition reactions. Notably, it forms azeotropes with water (84°C, 16% water) and methanol (64°C, 19% methanol), impacting purification processes.

Main Applications

In analytical chemistry, acetonitrile dominates as the preferred mobile phase for reverse-phase HPLC due to its UV transparency and elution strength. Pharmaceutical manufacturers utilize it in antibiotic production, peptide synthesis, and crystallization processes. The electronics industry employs high-purity acetonitrile for lithium battery electrolytes and semiconductor cleaning. Other applications include extraction of fatty acids, butadiene purification, and as a solvent for synthetic rubber production. Emerging uses involve organic light-emitting diode (OLED) manufacturing and carbon capture technologies.

Safety and Storage

As a flammable liquid (flash point 6°C), acetonitrile requires storage in explosion-proof facilities with proper grounding. Containers should be constructed from stainless steel or polyethylene, avoiding copper or brass due to potential complex formation. Personnel handling must wear chemical-resistant gloves (nitrile or butyl rubber) and vapor respirators when concentrations exceed 20 ppm. Spill management requires non-sparking tools and absorption with vermiculite or activated carbon. Decomposition above 400°C produces highly toxic hydrogen cyanide gas, necessitating temperature-controlled environments.

B2B Procurement Guide

Industrial buyers should specify required grade (technical, HPLC, or battery), with key parameters including water content (<0.1% for sensitive applications), UV absorbance (≤0.01 at 200nm for chromatography), and non-volatile residue (<5 ppm). Bulk procurement (ISO tank containers or 200L drums) typically offers 10-15% cost savings versus small packaging. Verify supplier certifications (ISO 9001, REACH compliance) and request batch analysis certificates. Regional considerations include transportation regulations (UN1648, Class 3 flammable liquid) and potential seasonal price fluctuations linked to acrylonitrile production cycles.