Citric Acid Monohydrate CAM CAS 5949-29-1: Properties, Grades, Applications, and Supplier Guide

Citric acid is one of the most widely used organic acids across numerous industries, ranging from food and beverage to pharmaceuticals and industrial applications. Among its various forms, Citric Acid Monohydrate (CAM), identified by the CAS number 5949-29-1, holds a prominent position due to its specific chemical properties and versatility. This comprehensive guide explores the essential characteristics, available grades, diverse applications, and key considerations for sourcing Citric Acid Monohydrate.

Understanding Citric Acid Monohydrate (CAS 5949-29-1)

Citric Acid Monohydrate is a naturally occurring tricarboxylic acid found abundantly in citrus fruits like lemons and limes. Commercially, it is predominantly produced through the fermentation of carbohydrates, such as molasses or corn steep liquor, utilizing the mold Aspergillus niger.

The defining characteristic of the monohydrate form, as the name suggests, is the presence of one water molecule for every molecule of citric acid in its crystalline structure. This contrasts with citric acid anhydrous, which contains no water of crystallization.

Chemical and Physical Properties

Understanding the fundamental properties of CAM is crucial for its appropriate application and handling.

• Chemical Formula: C6H8O7·H2O
• Molar Mass: 210.14 g/mol
• CAS Registry Number: 5949-29-1
• 모습: White, crystalline powder or colorless crystals.
• Odor: Odorless.
• Taste: Strongly acidic and tart.
• Solubility: Highly soluble in water; freely soluble in ethanol; sparingly soluble in ether.
• Melting Point: Approximately 100°C (loses water of crystallization), then decomposes at higher temperatures.
• pH (5% aqueous solution): Approximately 1.8.

The presence of the water molecule in CAM makes it slightly less hygroscopic (prone to absorbing moisture from the air) than the anhydrous form under certain conditions, which can influence storage and handling decisions. When heated to around 100°C, CAM loses its water of hydration and converts to the anhydrous form.

Grades of Citric Acid Monohydrate

To cater to the stringent requirements of different industries, Citric Acid Monohydrate is manufactured and categorized into specific grades. The grade indicates the level of purity and compliance with specific regulatory standards.

1. Food Grade

Food Grade CAM is the most commonly utilized form. It is manufactured under strict quality control measures to ensure it meets the safety standards required for human consumption. This grade complies with regulations set by authorities such as the Food Chemicals Codex (FCC), the European Union (E-number E330), and the U.S. Food and Drug Administration (FDA), where it is Generally Recognized As Safe (GRAS). Food grade material is rigorously tested for heavy metals, arsenic, and other potential contaminants.

2. Pharmaceutical Grade

Also known as Pharma Grade or USP/BP/EP Grade, this is the highest purity level of Citric Acid Monohydrate. It must strictly adhere to the rigorous monographs detailed in pharmacopeias such as the United States Pharmacopeia (USP), British Pharmacopoeia (BP), and European Pharmacopoeia (EP). Pharmaceutical grade CAM undergoes extensive testing to ensure ultra-low levels of impurities, ensuring its safety and efficacy for use in medications and medical devices.

3. Industrial / Technical Grade

Industrial or Technical Grade CAM is intended for applications where the highest levels of purity required for food or pharmaceuticals are not strictly necessary. While still a high-quality product, the tolerance for minor impurities might be slightly higher, making it a more cost-effective option for non-consumable applications. This grade is prevalent in manufacturing processes, water treatment, and agricultural applications.

Key Applications of Citric Acid Monohydrate

The versatility of CAS 5949-29-1 is reflected in its broad spectrum of applications. Its functions as an acidulant, pH regulator, preservative, and chelating agent make it indispensable across numerous sectors.

Food and Beverage Industry

The food and beverage sector is the largest consumer of Citric Acid Monohydrate. Its primary role is to enhance flavor and preserve the quality of consumable products.

• Flavor Enhancement: CAM imparts a pleasant, tart flavor that perfectly complements fruit-based beverages, sodas, candies, and jams. It balances sweetness and provides a refreshing “zing.”
• pH Regulation: As a strong organic acid, it effectively lowers the pH of food products. This acidic environment inhibits the growth of bacteria, yeasts, and molds, thereby significantly extending the shelf life of canned goods, sauces, and preserves.
• Chelating Agent: CAM binds to trace metals (like iron and copper) present in water or food ingredients. This prevents these metals from catalyzing oxidation reactions that can lead to color degradation and off-flavors in processed foods.
• Emulsification: In the dairy industry, it is used as an emulsifying agent in the production of processed cheeses, preventing the separation of fats and proteins.

Pharmaceutical and Nutraceutical Applications

The pharmaceutical industry relies heavily on Pharma Grade Citric Acid Monohydrate for various critical functions.

• Effervescent Formulations: CAM is a key ingredient in effervescent tablets and powders. When combined with a bicarbonate (like sodium bicarbonate) and water, a chemical reaction occurs, releasing carbon dioxide gas. This creates the characteristic fizz, facilitating the rapid dissolution and absorption of active pharmaceutical ingredients.
• pH Buffering: It is used extensively to adjust and stabilize the pH of liquid medicines, syrups, and intravenous solutions, ensuring the stability and optimal efficacy of the active ingredients.
• Flavor Masking: The strong tart taste of CAM helps mask the unpleasant bitterness of many medicinal compounds, improving patient compliance, especially in pediatric formulations.
• Mineral Supplements: It is used to manufacture citrate salts (e.g., calcium citrate, magnesium citrate), which are highly bioavailable forms of essential minerals used in dietary supplements.

Personal Care and Cosmetics

In the formulation of personal care products, CAM plays a crucial role in maintaining product stability and efficacy.

• pH Adjustment: The skin has a naturally slightly acidic pH. Citric acid is used in lotions, creams, shampoos, and body washes to match this natural pH, minimizing skin irritation and maintaining the skin’s protective barrier.
• Preservation Enhancement: By lowering the pH, it creates an environment less conducive to microbial growth, boosting the effectiveness of primary preservatives in cosmetic formulations.
• Bath Bombs: Similar to pharmaceutical effervescents, CAM reacts with baking soda in bath bombs to create the popular fizzing effect when dropped into water.

Industrial and Cleaning Applications

Industrial grade Citric Acid Monohydrate is a powerful and environmentally friendly alternative to harsh mineral acids in various technical applications.

• Cleaning and Descaling: CAM is highly effective at dissolving hard water stains, limescale, and rust. It is a common ingredient in household cleaners, bathroom sprays, and descaling agents for coffee machines and industrial boilers. Its chelating properties help bind mineral deposits, making them easier to wash away.
• 수처리: It is utilized in water treatment processes to adjust pH levels and act as a chelating agent to remove heavy metals from wastewater streams.
• 농업: In agriculture, it can be used to adjust the pH of soil or irrigation water to optimize nutrient availability for plants. It also finds use in certain animal feed formulations.
• Metal Finishing: It is employed in the passivation of stainless steel, a process that removes free iron from the surface and enhances the metal’s natural corrosion resistance. It offers a safer, less toxic alternative to nitric acid passivation.

Supplier Guide: Sourcing Citric Acid Monohydrate

Selecting the right supplier for Citric Acid Monohydrate is a critical step for manufacturers. The quality, consistency, and reliability of the supply chain directly impact the final product. Here is a guide to navigating the sourcing process.

1. Define Your Requirements

Before approaching suppliers, clearly define your specific needs:

• Grade: Determine whether you require Food, Pharmaceutical (USP/BP/EP), or Industrial grade based on your application and regulatory requirements.
• Quantity: Estimate your annual usage and preferred order sizes (e.g., pallets, full truckloads).
• Packaging: Specify the required packaging format, such as 25 kg bags, 50 lb bags, or 1000 kg bulk bags (supersacks).
• Particle Size: Depending on the application, you may need a specific mesh size (e.g., granular, fine powder). Ensure the supplier can provide the necessary particle size distribution.

2. Evaluate Supplier Credentials and Certifications

A reputable supplier should be able to provide documentation proving the quality and safety of their product.

• Quality Management Systems: Look for suppliers certified to ISO 9001 or similar quality management standards.
• Industry-Specific Certifications:
  • For Food Grade: Check for GFSI-recognized certifications (e.g., SQF, BRC, FSSC 22000), Kosher, and Halal certifications.
  • For Pharma Grade: Ensure the supplier adheres to Current Good Manufacturing Practices (cGMP) and provides a Drug Master File (DMF) or Certificate of Suitability (CEP) if required.
• Certificate of Analysis (COA): Always request a COA for the specific batch you intend to purchase. The COA should detail the test results for purity, moisture content, heavy metals, and other relevant parameters, confirming compliance with the requested specifications (e.g., USP, FCC).

3. Assess Supply Chain Reliability

Consistent supply is paramount to avoid production disruptions.

• Production Capacity: Ensure the supplier has the capacity to meet your volume requirements, even during periods of high demand.
• Sourcing Origin: Understand where the citric acid is manufactured. While much of the global supply originates in Asia, relying on a single geographic source can introduce risks. Consider suppliers with diversified sourcing strategies or robust domestic inventory.
• Logistics and Warehousing: Evaluate the supplier’s logistical capabilities. Do they have local warehousing to ensure shorter lead times and buffer against supply chain shocks?

4. Sample Evaluation

Before committing to a large order, request samples of the Citric Acid Monohydrate.

• Analytical Testing: Perform in-house testing or utilize a third-party laboratory to verify the sample meets the specifications outlined in the COA.
• Application Testing: Test the sample in your specific manufacturing process to ensure it performs as expected regarding solubility, pH adjustment, flavor profile, or other critical parameters.

5. Sustainability and Ethical Sourcing

Increasingly, companies are prioritizing suppliers who demonstrate a commitment to sustainability and ethical business practices.

• Environmental Impact: Inquire about the manufacturer’s environmental policies, waste management practices, and efforts to reduce their carbon footprint during the fermentation and crystallization processes.
• Social Responsibility: Ensure the supplier adheres to ethical labor practices and complies with relevant regulations regarding worker safety and fair treatment.

Handling and Storage

Proper handling and storage are essential to maintain the quality and flowability of Citric Acid Monohydrate.

• Storage Conditions: Store in a cool, dry, and well-ventilated area. Protect the product from direct sunlight and extreme temperatures.
• 습도 조절: While CAM contains water of crystallization, it can still absorb moisture from highly humid environments, which may lead to caking or clumping. Ensure packaging remains tightly sealed when not in use.
• 호환성 문제: Keep away from strong oxidizing agents and strong bases. Reacting citric acid with strong bases will generate significant heat.
• Safety Precautions: Citric acid is a mild irritant. When handling large quantities or fine powders, utilize appropriate personal protective equipment (PPE), including dust masks, safety goggles, and gloves, to prevent inhalation and avoid contact with eyes and skin.

결론

Citric Acid Monohydrate (CAS 5949-29-1) is a highly versatile and indispensable compound utilized across a vast array of industries. From ensuring the safety and flavor of our food to enabling the efficacy of medications and powering industrial cleaning processes, its unique properties make it a foundational ingredient in modern manufacturing. By understanding the distinct grades available and following a diligent sourcing process, businesses can secure high-quality CAM that meets their specific application requirements and regulatory obligations.

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