Solvents are widely used in the manufacturing industry. From cleaning assembly line equipment to engineering pharmaceutical products, solvents play a role at many different stages in the manufacturing process. However, if they are not properly removed, residual solvents can compromise the quality or safety of a product. Taking advantage of residual solvent testing is a way to combat potential quality issues and ensure a safe product.
What is a solvent?
A solvent is a liquid or gas that dissolves or extracts other substances. Some of the most common solvents used in manufacturing include butane, ethanol, propane, hexane and acetone. Solvents can be used to clean electronics and tools, dissolve greases and oils, or mix or thin pigments. Solvents are also very important for the creation of drugs and other pharmaceutical products. For example, solvents are often used at the beginning of the manufacturing process to create the active ingredients for ointments and other topical products.
What is a residual solvent?
Residual solvents are solvents that are used in the manufacturing of materials that are not completely removed after processing. Sometimes solvents are a critical part of the actual makeup of the product. For example, solvents can be used in glue and adhesive manufacturing to control the drying properties.
However, there are guidelines for the amount of residual solvents that can be left behind and still be considered safe. At unsafe levels, they can either be harmful to the environment or humans. In addition, residual solvents can also compromise the quality and/or functionality of the product. For example, removing cleaning solvents is essential during the processing of a circuit board. If residual solvent is present, the conformal coating and/or solder mask will not adhere properly to the circuit board.
What is residual solvent testing?
Residual solvent testing determines whether residual solvents, or other impurities, are present, and if they’re present in harmful amounts. It can also determine whether the proper solvent purging process was followed during product development.
What are the benefits of residual solvent testing?
Simply put, residual solvent testing is a way to ensure product quality and safety.
For example, ethanol and other solvents are often used in the production of pharmaceutical products. Since pharmaceutical products are ingested or implanted in the body, residual solvent testing is critical to ensure that solvents are not present at health threatening levels.
Solvents are also frequently used in the production of plastic packaging for various food products. If too much of the solvent is retained in the packaging, it could give off an unappetizing odor or spoil the taste of the food. Testing can quantify the level of residual solvents and determine if they will cause odor or taste issues.
What techniques are used?
Headspace GC/MS is a common technique used in residual solvent testing.
GC/MS analysis, or gas chromatography mass spectrometry, identifies the precise composition of a sample. During this process, the sample is injected into a gas chromatograph to volatilize the sample and separate the various components. The separated components then go into a mass selective detector to identify how much of each element is present.
Headspace analysis is conducted in tandem with GC/MS analysis. This technique analyzes the volatile and semi-volatile organic compounds given off by a sample during heating or over time. Static headspace analysis is ideal for analyzing residual compounds.
Headspace GC/MS can identify and quantify which residual solvents are present in a sample. If high levels of residual solvents are found, manufacturers will be able to trace the issue to a step in the manufacturing process and make the necessary adjustments.
Residual solvent testing is a must for any organization that uses solvents in manufacturing and production processes. Residual solvent testing is a way to avoid contamination and product failures, and ensure that your product is safe for human use.
For more information on residual solvent testing from Innovatech Labs, get in touch with us today.