Headspace caps are a type of closure or seal used for headspace analysis vials. They are designed to secure the vials to prevent any leakage of volatile compounds from the sample within. The accuracy and integrity of the analysis heavily depends on the security of the vial’s seal. Most caps include a septum, which is a thin layer of silicone and polytetrafluoroethylene (PTFE) that will be punctured by the gas chromatography (GC) syringe needle during analysis. Headspace caps come in a number of different sizes and customizations, depending on the application and type of headspace vial required. They are made from high-quality materials that can withstand exposure to extreme temperatures, harsh chemicals, and other environmental elements. Examples of such materials include: steel, aluminum, polypropylene, and magnetic material. Headspace caps play a critical role in the operation of headspace analysis; without them, scientists would not be able to reproduce experiments or analyses, or put full confidence in their findings.
What is headspace analysis?
Headspace analysis is a technique that is used to detect and measure the concentration of volatile organic compounds (VOCs) within a sample—such as food products, environmental samples, and biological fluids. VOCs are chemical compounds with high vapor pressure and low boiling points, which causes them to evaporate easily into the air. Headspace analysis is typically used in chemistry, biology, food and beverage analysis, environmental science, and pharmaceuticals.
The process begins when a small portion of a sample is put into a sealed vial, then heated to a specific degree. As the temperature rises, VOCs are released from the liquid or solid to accumulate in the headspace above the sample. A small amount of that headspace gas is then withdrawn from the vial and injected into a GC or gas chromatography-mass spectrometry (GC-MS) system for analysis. The system separates the VOCs based on individual chemical or physical properties, measuring the concentration of each compound in the sample. The results are collated into a chromatogram, which shows peak areas that relate to the concentration amount of a compound within the sample.
The history of headspace analysis closely follows that of gas chromatography. After its discovery in the 1940s, scientists continued to refine the process throughout the 1950s and 1960s, finding new techniques such as static and dynamic headspace analysis. The 1980s and ‘90s introduced solid-phase micro extraction (SPME) and headspace trap (HST) techniques, improving the sensitivity and selectivity of the analysis. Currently, headspace analysis remains a widely used method across many different industries.
Does ILT manufacture headspace caps?
ILT currently offers a variety of products for use in headspace analysis. The catalog includes screw caps, steel screw caps, polymagnetic screw caps, microcenter liners, crimp caps, and septa. All products are tested in ILT’s onsite laboratory to ensure quality control. This determination to consistently meet industry standards is what keeps ILT in position as the global producer of lined caps.