CAS 108-59-8 refers to dimethyl maleate, an important organic compound widely used in various industries such as plastics, resins, and pharmaceuticals. As a reliable supplier of CAS 108-59-8, we understand the significance of standard test methods in ensuring the quality and safety of this compound. In this blog, we will delve into the standard test methods for dimethyl maleate, providing valuable insights for our customers and industry professionals.
Physical and Chemical Properties Testing
Appearance and Color
The appearance and color of dimethyl maleate are fundamental physical properties that can indicate its purity and quality. A visual inspection is typically the first step in assessing these properties. The compound should appear as a clear, colorless to slightly yellowish liquid. Any significant deviation from this appearance, such as turbidity or a dark color, may suggest the presence of impurities or degradation products.
Boiling Point and Melting Point
Determining the boiling point and melting point of dimethyl maleate is crucial for characterizing its thermal properties. These values can be measured using standard techniques such as distillation and differential scanning calorimetry (DSC). The boiling point of dimethyl maleate is approximately 204 - 205 °C, while the melting point is around -19 °C. Deviations from these values can indicate impurities or variations in the chemical structure.
Density
The density of dimethyl maleate is another important physical property that can be used to assess its purity. It is typically measured using a pycnometer or a density meter at a specified temperature, usually 20 °C. The density of dimethyl maleate is approximately 1.15 g/cm³. Any significant deviation from this value may suggest the presence of impurities or a change in the chemical composition.
Purity Testing
Gas Chromatography (GC)
Gas chromatography is a widely used analytical technique for determining the purity of dimethyl maleate. It separates the components of a sample based on their volatility and affinity for the stationary phase in the column. A high - purity dimethyl maleate sample should show a single, sharp peak in the GC chromatogram, indicating the absence of significant impurities. The area under the peak can be used to quantify the amount of dimethyl maleate in the sample.
High - Performance Liquid Chromatography (HPLC)
HPLC is another powerful analytical tool for purity testing. It is particularly useful for separating and quantifying polar and non - volatile compounds. In the case of dimethyl maleate, HPLC can be used to detect and quantify impurities such as maleic acid, fumaric acid, and other related compounds. The separation is based on the interaction between the sample components and the stationary phase in the column, and the eluted components are detected using a suitable detector, such as a UV - Vis detector.
Nuclear Magnetic Resonance (NMR) Spectroscopy
NMR spectroscopy is a valuable technique for determining the chemical structure and purity of dimethyl maleate. It provides information about the molecular structure, including the number and type of atoms, their connectivity, and the environment in which they are located. By comparing the NMR spectrum of a sample with the spectrum of a pure reference compound, it is possible to identify and quantify impurities and confirm the chemical structure of dimethyl maleate.
Chemical Composition Analysis
Elemental Analysis
Elemental analysis is used to determine the elemental composition of dimethyl maleate. It typically involves measuring the percentage of carbon, hydrogen, and oxygen in the compound. This can be done using techniques such as combustion analysis, where the sample is burned in the presence of oxygen, and the resulting gases are analyzed to determine the elemental composition. The theoretical elemental composition of dimethyl maleate is approximately 50.0% carbon, 5.6% hydrogen, and 44.4% oxygen. Deviations from these values can indicate the presence of impurities or a change in the chemical structure.
Infrared (IR) Spectroscopy
IR spectroscopy is a useful technique for identifying functional groups in dimethyl maleate. It measures the absorption of infrared radiation by the sample, which is characteristic of the vibrations of different chemical bonds. The IR spectrum of dimethyl maleate shows characteristic peaks corresponding to the carbonyl group (C = O), the ester group (C - O - C), and the carbon - carbon double bond (C = C). By comparing the IR spectrum of a sample with the spectrum of a pure reference compound, it is possible to confirm the chemical structure and identify any impurities that may have different functional groups.
Safety and Toxicity Testing
Acute Toxicity Testing
Acute toxicity testing is an important part of the safety assessment of dimethyl maleate. It involves exposing test animals (such as rats or mice) to a single, high dose of the compound and observing the resulting adverse effects. The LD50 (lethal dose 50%) value, which is the dose that causes death in 50% of the test animals, is commonly used to express the acute toxicity of a compound. For dimethyl maleate, the LD50 value for oral administration in rats is typically in the range of 2000 - 5000 mg/kg.
Skin and Eye Irritation Testing
Skin and eye irritation testing is used to assess the potential of dimethyl maleate to cause irritation or damage to the skin and eyes. It involves applying the compound to the skin or eyes of test animals and observing the resulting effects. Dimethyl maleate is generally considered to be a mild skin and eye irritant.
Environmental Toxicity Testing
Environmental toxicity testing is important to evaluate the potential impact of dimethyl maleate on the environment. It typically involves testing the compound's toxicity to aquatic organisms such as fish, algae, and daphnia. These tests can provide information about the compound's potential to cause harm to the environment and help in the development of appropriate environmental management strategies.
As a supplier of CAS 108-59-8, we are committed to providing high - quality dimethyl maleate that meets or exceeds the industry standards. We use a combination of these standard test methods to ensure the purity, quality, and safety of our products. In addition to dimethyl maleate, we also supply other related organic chemicals such as N,N'-Methylenebisacrylamide N,N'-Methylenediacrylamide MBA CAS 110-26-9, Methyl Oleate CAS 112-62-9, and Sodium Tetraphenylboron CAS 143-66-8.
If you are interested in purchasing dimethyl maleate or any of our other products, we encourage you to contact us for more information and to discuss your specific requirements. We look forward to the opportunity to work with you and provide you with the highest quality products and services.
References
- ASTM International. Standard Test Methods for Chemical Products.
- United States Pharmacopeia (USP). General Chapters for Chemical Analysis.
- European Pharmacopoeia (Ph. Eur.). Methods for the Analysis of Organic Compounds.
- IUPAC Compendium of Chemical Terminology (the "Gold Book").
