The United States Environmental Production Agency (USEPA) wrote Method 8260 for the determination of Volatile Organic Compounds (VOCs) in nearly all types of sample matrices regardless of water content including ground and waste waters, soils, sludge, tar, waste solvents… Method 8260 incorporates several preparative techniques including purge and trap (USEPA Method 5030 and 5035) and headspace sampling (USEPA Method 5021). For wastewater compliance monitoring the USEPA promulgated Method 624. This method is used for the determination of VOCs in municipal and industrial waste water using purge and trap sampling. Since Method 8260 and 624 both involve water matrices, many laboratories run an extended compound list in order to accept both types of water samples.
USEPA Method 8260 encompasses over 100 compounds, many of which can be determined using a purge and trap preparative technique. Method 5030 describes the purge and trap procedure for the determination of VOCs in water or water miscible samples. While Method 5035 applies to solid, oil, sludge or tar… matrices. Both methods involve purge and trap sampling in conjunction with Gas Chromatography/Mass Spectrometry (GC/MS) for the determination of the VOCs.
As the samples examined using Method 8260 can be quite diverse, it is important to have a sampling system that can accommodate all types of samples. Water samples can be directly transferred to the sparge vessel on the purge and trap concentrator, while soil samples can be either extracted in methanol and sampled as a water or can be run directly from a sample vial with the addition of water. For this reason, many laboratories use autosamplers with the ability to run both water and soil matrices.
Purge and trap sampling involves purging samples with an inert gas, most laboratories purge at a rate of 40mL/min for 11 minutes while trapping the analytes onto an adsorbent trap. The trap is then heated and desorbed to the GC/MS for separation and analysis. When performing purge and trap sampling it is important to control the amount of water desorbed over to the GC/MS. For this reason, the EST Analytical Evolution purge and trap concentrator has incorporated the ARID system for better water management.
Cross contamination between samples can also be a problem when performing Method 8260 or 624 as samples can be highly polluted. The EST Analytical Centurion W/S incorporates two different needles for water and soil samples in order to prevent cross-contamination. The Centurion transfers water samples directly from the vial using one needle and has a separate needle for the purging of soil samples from the sample vial. Furthermore, since the sparge vessel can also contribute to carryover, the Evolution uses a patented heater in order to “bake” the sparge vessel between samples thus ensuring lower carryover.
If you are just getting started with Purge and Trap sampling and analysis, contact us to reach one of our application specialists who would be glad to offer some tips and tricks. Feel free to look at some of our application notes which will help you on your way.
USEPA Method 8260 is a procedure used to determine Volatile Organic Compounds (VOCs) in a variety of matrices. The VOCs are sampled and introduced to a Gas Chromatograph (GC) via purge and trap, direct injection or distillation with purge and trap being the most commonly used technique for VOC preparation. In July of 2018, the USEPA released Method 8260D, this new method incorporated several changes including new BFB tune criteria, analyte additions, and blank requirements.
The United State Environmental Protection Agency (USEPA) Method 8260 recommends an eleven-minute purge time at 40ml/min purge flow. Due to this restriction, environmental analysts need to investigate other means to decrease cycle times without sacrificing analytical results. This application note will examine decreasing cycle times within the USEPA Method requirements.
During purge and trap concentration, Helium is used to purge volatile analytes out of the sample matrix in order to concentrate them onto an analytical trap. Due to the Helium shortage, it has become necessary to find another means of purging analytes out of the sample. This application will examine using Nitrogen as the purge gas for purge and trap sampling.
Carryover is a common problem resulting in sample reruns and reduced productivity in environmental labs. Many advances over the years have been developed to tackle this issue. These innovations vary from increasing bake times and bake flows to changing the flow path tubing to more inert materials. This application will evaluate a patented innovation for cleaning the sparge vessel during an analytical sequence.
This application will scrutinize Purge and Trap sampling coupled with Gas Chromatography and Mass Spectrometry (GC/MS) for the analysis of volatile organic compounds (VOCs) in industrial discharges and other environmental samples. With the number of organic pollutants in use increasing, the potential for continued contamination of water resources still exists. This leads to the need for updated laboratory sampling and analysis instrumentation; environmental methods must meet certain criterion to account for these changes.
This application will examine purge and trap sampling in conjunction with Gas Chromatography/Mass Spectrometry (GC/MS) for the determination of low levels of 1,2,3-Trichloropropane (1,2,3-TCP). 1,2,3-TCP is usually found at industrial waste sites. It can be used as a solvent or as a degreasing agent and is also a chemical intermediate when synthesizing other compounds.
1,4-Dioxane is commonly used as a cleansing agent during the manufacture of pharmaceuticals. It is also employed as a stabilizer for chlorinated solvents, so it is commonly found at industrial sites contaminated with these solvents. The Environmental Protection Agency (EPA) has classified 1,4-dioxane as a likely carcinogen and thus it is essential to be able to detect 1,4-dioxane at low concentration levels.
The United States Environmental Protection Agency (USEPA) Method 8260 has an extensive list of analytes that can be analyzed by purge and trap sampling. Two of the more troublesome compounds on this list are Ethanol and 1, 4-Dioxane. Both of these compounds are water miscible and Selective Ion Monitoring (SIM) is required in order to detect these compounds at lower levels. This application will compare linearity, method detection limits, precision and accuracy and carryover of several purge and trap sampling parameters.
For more than 30 years, oxygenated compounds have been added to gasoline. The addition of these compounds provides two benefits: one, the reduction of pollution caused by car emissions as oxygenated gasoline burns more efficiently and two, the improvement of engine performance. Due to the prolonged use of these compounds, there has been an increase in the contamination of ground water as underground storage tanks have been found to leak causing their contents to leach into the soil.
The ingestion of Epichlorohydrin (ECH) is toxic in drinking water and has the possibility of causing cancer if a large amount is consumed. The maximum concentration permissible in drinking water regulated by the EPA is 0.1µg/L. This paper will compare how purge and trap sampling and Solid Phase Micro-Extraction (SPME) detect ECH in water samples.
The efficiency of a Gas Chromatograph depends significantly on the type of column that is installed in it. In order to properly separate every compound in a mixture from each other, the optimum column must be used.
The United States Environmental Protection Agency (USEPA) Method 8260 is used in order to ascertain volatile organic compounds in waters, soils and solid waste samples. Often times, soil and solid waste samples are so highly contaminated the sample needs to be dispersed in methanol. This application will investigate automated sampling of methanol soil extractions.
During volatile analysis, samples are purged with an inert gas in order for the Volatile Organic Compounds (VOCs) to be swept out of the sample and onto an analytical trap. Purge flows and times are recommended by the United States Environmental Protection Agency (USEPA). For years the USEPA recommended purge flow and time was 40ml/min for 11 minutes, however in USEPA Method 524.3 and 4 there is approval to vary purge flows and times.
The presence of Tetraethyl Lead (TEL) is toxic in drinking water. It has the possibility of decreasing brain function, causing headaches, as well as kidney damage with continuous ingestion. The maximum concentration permissible in drinking water regulated by the Environmental Protection Agency (EPA) is 15µg/L for adults. This paper will go into detail of how purge and trap sampling can accurately detect Tetraethyl Lead in water samples
The determination of Volatile Organic Compounds (VOCs) in the United States Environmental Protection Agency (USEPA) Method 8260 encompasses many different matrices and in doing so has numerous sampling, quality control, and calibration requirements. The method also has an extensive calibration range. All of these factors play into the complexity of sampling and analysis thus, creating ways to streamline sampling while still maintaining sample integrity and method compliance is always of interest to environmental laboratories.
USEPA Method 8260 involves purging analytes out of a water matrix. During a split injection, the sample volatilizes in the inlet and is swept by the carrier gas through the liner onto the GC column with a portion of the sample being split off and sent out the split vent line. This application will explore the effect split ratios have upon USEPA Method 8260 analytes.
In studying sample throughput demands, one thing is evident; purge and trap cycle time is the limiting factor in increasing laboratory productivity. EST Analytical has addressed this challenge so as to maximize your sample throughput and minimize your cost. The use of our Centurion WS auto-sampler and two Encon Evolution concentrators coupled to one GC/MS system can double your sample throughput without doubling your cost.
There have been many advances in purge and trap analysis in the past ten years. These improvements vary from water management to limiting the amount of sample carryover. However, in creating a more efficient concentrator, the ability of the concentrator to tolerate large amounts of methanol has become an issue. This application note will explore how methanol affects curve linearity and compound response.
EST Analytical has developed a syringe feature for the Centurion Autosampler that can dilute samples up to 400 times the original concentration. This feature is fully programmable and the sample vial does not have to be compromised in order to dilute the sample because the dilution process is automated. The sealed vial can be placed in the sample tray while the Centurion does all of the work.
Volatile contaminants in drinking, ground and wastewaters are an ongoing environmental concern throughout the world. Testing for these contaminants is generally done using a Gas Chromatograph (GC) coupled to a Mass Spectrometer. However, sampling for these compounds is dependent on the environmental regulations of the country in which you are testing. The USEPA methods for extracting VOCs from environmental samples require purge and trap sampling. On the other hand, in Europe and Canada, it is common to use static headspace sampling for the measurement of VOCs.
Polycyclic Aromatic Hydrocarbons (PAHs) are formed from incomplete burning of carbon containing fuel. There are thousands of PAH compounds in the environment, and of those; there are several that have been established to begin with of concern for the environment. Extraction of PAH compounds involves a large amount of sample and solvent, and because of this, there is a lot of solvent waste. The use of Large Volume Injection (LVI) in conjunction with a Programmable Temperature Vaporizer (PTV) aids in eliminating some of this solvent waste, and reduces labor and shipping costs due to the ability to extract smaller volumes of sample without sacrificing sensitivity. This analysis will compare PAH compound response of a standard injection versus a large volume injection.
In general, Gasoline Range Organic (GRO) compounds correspond to a range of hydrocarbons from C6 to C10. These hydrocarbons have boiling points below 170°C and are often found in ground water and soils. The cause of this water or soil contamination can vary from the simple leaking underground storage tank to catastrophic such as the Gulf Oil spill. When GRO compounds are found, the site of the pollution needs to be tested in order to determine the level of the contamination. One method to determine the amount of contamination is to perform static headspace sampling in conjunction with Gas Chromatography/Mass Spectrometry analysis. This application note will explore static headspace sampling of GRO water samples using the EST Analytical LGX50.
Due to current events, the importance of determining volatile petroleum hydrocarbons in both soils and waters has become an issue. The complexities of the matrices that these compounds are found in can also inhibit accurate detection. Analysis of volatile petroleum hydrocarbons by purge and trap concentration in conjunction with GC/MS will be presented in this poster.