SUMMA canisters

Air in the community was sampled for VOCs by Summa canister (8-hour orifice, and 7 m stainless steel frit filter) and for reduced sulfur gasses by Tedlar bag. These samples were 24 hour express mailed to Performance Analytical Inc. and analyzed as described above. Aerosols (PM2.s and PMi0)... 

Collection of air samples in stainless steel canisters whose surfaces have been passivated is another common collection technique for VOCs. (Aluminum has also been used but the stability of polar organics in them is poor Gholson et al., 1990.) Indeed, this method is used not only for sampling air but in medical applications as well, where they have been used to sample organics in a single breath (Pleil and Lindstrom, 1995). Passivation of the canisters is often carried out using a process called SUMMA and hence referred to as SUMMA canisters. The canisters also have to be thoroughly cleaned before use an example of one such procedure is described by Blake et al. (1994). The sample is then typically preconcentrated by transfer to a cold trap prior to injection onto the GC column (e.g., see Blake et al., 1994). 

Summa canisters are evacuated cylinders that allow the attachment of regulators that collect air over a preset time period. Common regulators are instantaneous (grab), 8 h, and 12-8 h regulators. 

A short description of the methods used for analysis of 1,1,1-trichloroethane in environmental samples is presented in Table 6-2. An extensive list of methods for analysis of 1,1,1-trichloroethane in environmental samples can be compiled from the literature. Two methods are commonly used for collection of 1.1.1-trichloroethane and other volatile organics in ambient and occupational air. One method uses adsorbents to trap and concentrate organics in air. and the other method uses passive stainless steel canisters (SUMMA canisters). The advantage of SUMMA canisters is that sample breakthrough does not occur with this method as it may occur with adsorbent tubes (Hsu et al. 

Breath Three breath samples were typically collected before and after the work period. Using devices called SUMMA canisters, a scientist from the EPA collected breath samples from selected enrollees and analyzed the specimens... 

The contaminated airstream provided by the air stripper unit contained volatile organic compounds as analyzed from Summa canister tests by Air Toxics, Ltd. using EPA method TO-14. These compounds, listed in Table 22.4.1, consisted primarily of trichloroethylene and trace quantities of dichloromethane, 1,1-dichloroethene, cis-1,2-dichloroethane, chloroform, carbon tetrachloride, and benzene. The other compounds present in the outlet presumably formed during treatment. 

Table 22.4.1. Results from the Summa canister tests of inlet and outlet reactor air streams during the McClellan tests. The two inlet and two outlet samples were taken sequentially and represent approximately replicate samples...

On the last day of testing, grab samples were collected in Summa canisters and delivered to a loeal analytical laboratory (Air Toxics, Ltd., Folsom, CA) for TO-14 analysis to confirm the analyses provided by the MTI gas chromatographs and to provide outlet TCE concentrations that were below our GCs detection limits. Replicate samples were reported as 13000 ppbv for TCE in inlet air, and 280 and 660 ppbvTCEinthe outlet (Table 22.4.1). This corresponds to 97.8% and 94.9% removal of TCE. 

Flexible sampling bags made of different materials or evacuated rigid containers, such as SUMMA canisters, are used for grab sample collection. 

Air. A grab sample can be collected by a preevacuated steel Summa canister or by drawing air through a glass bulb sampler equipped with Teflon stopcocks at both ends, using a personal sampler pump. If desired, an IS (dissolved in methanol) can be added to the bulb... 

Carbopack and Envicarb X) before transfer to the GC by heating. A similar approach for batch samples (electro polished SUMMA canisters) was employed by trapping analytes at liquid nitrogen temperatures before introduction into a GC-FID by Hudson and Ariya [91]. Both adsorption methods allowed for the determination of VOC and SVOC. 

The Determination of Volatile Organic Compounds in Air Using SUMMA Canisters and GCMS with Cryogenic Trapping... 

SUMMA canisters are stainless-steel spheres that have a passivated stainless-steel interior that is inert to VOCs and allow for long-term storage of air. The canisters come in a variety of sizes the most common size is 6 L, and they have a needle valve that allows for sampling and removal of air. SUMMA canisters that are coated internally with fused silica have become available. USEPA methods TO-14A and TO-15 describe the determination of VOCs in air using the SUMMA canisters. TO-15 is a new version of the canister method and has an expanded target hst with a total of 97 VOCs that include some of the more polar and water-soluble VOCs. Method TO-15 establishes method performance criteria for acceptance of data that allows for the nse of alternate bnt equivalent sampling equipment. TO-15 inclusively uses GCMS and has enhanced quality assurance provisions. 

SUMMA canisters are cleaned by alternatively filling them with humidified air, venting them, and then pulling a very low vacnnm (<0.05 mm Hg) for a total of three cycles. Sometimes the canisters require heating during the process to remove less volatile compounds. On the last cycle they are filled with humidified air, and each canister must be analyzed to certify that it is clean of VOCs. A pressurized leak test is also required. The cleaned canisters are then evacuated and ready for sampling. 

Possible and, for certain carrier materials, already known decomposition reactions have been mentioned. For this reason, another method is favoured by the EPA for air analysis. Electropolished and passivated canisters, called SUMMA canister expressing the highest inertness, of about 2 L capacity, maximum up to 15 L are evacuated for sample collection. The whole air samples collected onsite on opening the canister can be measured several times in the laboratory following EPA methods such as TO-14 or TO-15. Suitable samplers are used, which are connected online with GC-MS. Cryofocussing is used to concentrate the analytes from the volumes collected. If required, the sample can be dried with a semiper-meable membrane (Nafion drier) or by condensation of the water (MCS, see also section 2.1.5.2). Adsorption materials are not used in these processes. 

Keywords air SUMMA canister thermodesorption volatile halogenated hydrocarbons cryofocusing water removal thick film column. 

The EPA (US Environmental Protection Agency) describes a process for sampling and analysis of volatile organic compounds (VOCs) in the atmosphere. It is based on the collection of air samples in passivated stainless steel canisters (SUMMA canisters). The organic components are separated by GC and determined using conventional GC detectors or by mass spectrometry (Figure 4.1). The use of mass spectrometers allows the direct positive detection of individual components (Madden, 1994). 

Static field Stationary phase SUMMA canister... 

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