An overview of Purge and Trap Gas Chromatography. Purge and Trap Water Analysis: An overview
Gas Chromatography (GC) is the process of analyzing compounds using a gas chromatograph-a machine that analyzes compounds after they are separated from the sample and vaporized. A column inlet (a. k. a. injector) removes the compounds from the sample, vaporizes them, and injects them into the column of the chromatograph. For purge and trap gas chromatography, which is typically performed to analyze compounds that occur at low parts per billion (ppb) levels, a purge and trap column inlet is used.
The most popular application hplc autosampler for purge and trap gas chromatography is the analysis of Volatile Organic Compounds (VOCs), naturally occurring substances that can cause adverse health conditions and damage to the environment. In addition to being toxic to humans and animals even in small amounts, VOCs are dangerous for their tendency to vaporize at room temperature-a trait that allows them to pervade work environments and the natural environment with ease. Different products and environments have different VOC regulations, some of which are enforced by the Environmental Protection Agency (EPA), but ensuring that VOCs remain absent or within the proper limit is always accomplished with the help of GC.
VOC analysis is the best-known application for GC, but it is not the only application. GC is also used to analyze compounds that affect the taste and smell of various foods and beverages, and numerous cosmetic products and fragrances.
Purge and trap gas chromatographyis valuable for identifying low level compounds in soil and liquid samples, particularly VOCs that threaten the safety of work environments, the natural environment, and consumer products. When the goal of GC is to analyze compounds that are present at low ppb levels, the accuracy of the analysis depends on using the right type of inlet column, one that performs the purge and trap function.
Purge and trap water analysis is a method of lab testing that uses specific systems to facilitate the chromatographic testing of liquid samples. The mechanism of the auto sampler distinguishes the process from other types of chromatographic testing, such as static head space testing and dynamic head space testing. Unlike these processes, the purge and trap method excels at isolating compounds that are present at low parts per billion (PPB) levels. This makes it ideal for testing substances for trace amounts of artificial chemicals and Volatile Organic Compounds (VOCs), which are naturally occurring, carbon-based compounds that vaporize at room temperature.
Food grade beverages seldom contain dangerous levels of artificial chemicals, but they are a surprising source of VOCs. In drinking water, VOCs may result from pollution, the improper filtration of organic matter from the liquid, or an unforeseen result of the filtration process. In flavored beverages, the source is more urbane: natural ingredients such as fruits and vegetables. Consider the number of VOCs that the following flavor foods contain: