Trans-Aconitic Acid: Properties, Structure, and Uses

What is Trans-Aconitic Acid?

Trans-aconitic acid appears in nature, most often found in sugarcane and other plants. Its chemical name comes from its origin in aconite plant species. People who have worked with citric acid chemistry know trans-aconitic acid as a tricarboxylic acid, which means it features three carboxyl groups on its backbone. The acid falls under the category of unsaturated organic acids, tying it into the larger family of carboxylic acids involved in metabolic pathways.

Structure and Molecular Details

The molecular formula for trans-aconitic acid is C6H6O6. Its structure features a chain of six carbon atoms with three carboxylic acid groups placed at the first, second, and fourth carbons. A double bond connects carbons two and three, and the trans configuration places the carboxyl groups on opposite sides of the double bond. The structure gives the molecule certain physical and chemical characteristics. Molecular weight stands at 174.11 g/mol. The unique backbone, based on tricarboxylic acid design, means this molecule participates in biochemical reactions central to many living systems.

Physical Properties

Pure trans-aconitic acid usually comes as a white crystalline solid or flakes, though it can sometimes show up as powder or even in pearl forms, depending on processing methods. The solid state remains stable under standard storage conditions, but it dissolves readily in water to form a clear solution. In terms of density, bulk samples range around 1.63 g/cm³. Melting point sits near 190°C. As a solid, the acid does not absorb moisture very fast, but in high humidity, some clumping occurs in powdered forms. In solution, the acid remains colorless, with a sharp acidic taste and a slight tart odor.

Chemical Properties and Behavior

Trans-aconitic acid behaves as a weak organic acid in aqueous solution, meaning it only partially dissociates in water. When handled in an industrial context, people usually store it in sealed containers away from strong bases or oxidizers to prevent breakdown. The acid’s three carboxyl groups make it useful in chelation and as a buffering agent. Add a little heat, and it slowly decomposes, giving off carbon dioxide and leaving behind simpler organic acids. In research, chemists use it for studying citric acid cycle intermediates because of its structural similarity.

Appearance: Flakes, Solid, Powder, Pearls, and Liquid Solution

When real people think about working with chemical raw materials, format matters. Trans-aconitic acid comes in the form of bulky flakes for easy weighing or as a fine crystalline powder to help in laboratory mixing. Some suppliers offer it as pearls, which flow well and measure out easily for industry. The liquid solution form—usually a simple aqueous solution—shows up in applications that need acid already dissolved. Anyone planning to handle large quantities should think about dust management and personal protective gear, especially with powders.

HS Code and Specification Standards

In international trade, trans-aconitic acid ships under HS Code 2918.19. When buying, people look for minimum purity standards of no less than 99% for chemical synthesis or food research. Water content typically falls below 1%, which helps prevent unwanted clumping or early breakdown. Buyers and regulators sometimes ask for metal ion content, as trace metals may affect downstream chemistry—especially in high-purity applications. Packing standards often include sealed drums or bottles with clear labeling.

Applications, Safety, and Handling

Trans-aconitic acid is used mainly in research and as a building block for other chemicals. Some fermentation and metabolic studies use the acid to probe the citric acid cycle. In the food industry, some regions allow its use as a pH regulator or additive after careful evaluation. To be clear: this material does not count as a common household acid and calls for qualified handling. Safety guidelines recommend working with gloves, goggles, and dust protection, especially in powder and flake forms. If the acid makes contact with skin or eyes, rinse immediately with water and seek medical attention if irritation persists. On inhalation or ingestion, prompt medical help is important.

Hazards and Environmental Impact

Trans-aconitic acid falls under the category of low-to-moderate hazardous substances, based on current material safety studies. It is not listed as a carcinogen, but repeated or prolonged exposure may produce mild irritation of skin, respiratory tract, or eyes. In a spill, small amounts can mix with soil and water but break down rapidly under natural conditions, so it poses less risk of long-term toxicity compared to synthetic chemicals. Still, users should follow disposal guidelines—neutralize with mild base and dilute with water before sending waste down the drain, according to local regulations.

Industry Experience and Solutions

My experience working in organic chemistry labs showed me that stable acids such as trans-aconitic acid save time for researchers. Because of its low reactivity except in controlled conditions, storage does not become a logistical nightmare—sturdy containers and a cool, dry environment keep it safe for months. Raw material suppliers who invest in good packaging reduce loss and waste during shipping. For industries scaling up, focusing on efficient purification methods leads to higher yields and lower contamination rates. If anyone faces clogging or crystallization in lines, switching physical forms—from powder to pearls or solution—resolves most handling problems. People working on the regulatory side push for training and data sheets in multiple languages to boost safety, especially where raw acid may change hands several times before use. As chemical supply chains spread across borders, clear labeling and batch testing are the backbone of quality assurance—the details that keep both labs and industry running smoothly.