Sample Bags
Can Say Goodbye to Tedlar and its Universal Properties?
EAS has been providing Tedlar bags for years to assist with sampling, and still supplies bags. For specific applications you might want to order the bags that suits your application from SKC.
The standard 72 hour holding time may not apply to all bags. Some projects are requesting shorter holding times.
EAS will analyze your samples in 24 hours if possible. Call and let us know your schedule so we can have all the equipment calibrated when your bags arrive.
Gas Sampling Bags
Tedlar bags which have been used for years for air sampling are on longer available since DuPont has quit making the Tedlar material. Most companies have substituted an alternative materials for the gas sampling bags, but none of them has the universal properties of Tedlar. It is important to select the bag type that will work for your application. This summary of the bag types is based on the SKC Catalog (800) 752-8472.
EAS recommends bags with plastic fittings for hydrogen sulfide and reduced sulfur compounds. For ambient VOC's the canister is the best choice, since they have better stability, lower background, and are easier to use. For source samples the bags work fine, but be sure to notify the lab when the samples are arriving.
PVD, Kynar Solef, Hylar Gas Sample Bags
These bags are a good general purpose bag. They have low VOC and sulfur background, and good stability for some (but not all) VOC's and hydrocarbons. They have good stability for methane and carbon dioxide. They are stable for sulfur compounds for 24 hours. For sulfur sample collection be sure to use the plastic fittings, since the stainless steel fittings will degrade the sulfur gases.
FlexFoil Plus Gas Sample Bags
This is a multi-layer bag with a metal foil layer to decrease permeability. These bags have a low VOC background, and have good stability for low molecular weight compounds such as permanent gases, methane, and carbon dioxide. They have good 48 hour stability for hydrogen sulfide, carbonyl sulfide, and mercaptans. For sulfur sample collection be sure to use the plastic fittings, since the stainless steel fittings will degrade the sulfur gases.
Flex Film Gas Sampling Bags
These are economical bags that are good general purpose bags. They have low VOC background, and longer stability for hydrocarbons compared to other bags. They also have good stability for CO, CO2, and methane. The have acceptable stability for some sulfur compounds.
Fluoro Film Gas Sampling Bags
These bags have very low VOC and sulfur background, but they have poor stability for most VOC's and sulfur compounds. They should be analyzed in 24 hours.