Sampling for SVOCs

An important element in assuring the collected sample representativeness is the use of sample containers that sustain sample integrity. We collect water samples for VOC analysis in 40-ml VOA vials with screw-on PTFE-lined silicon rubber septum caps. The PTFE liner of the septum should always face down to contact the water. Water samples for SVOC analyses are collected into 1-liter amber glass bottles with PTFE-lined lids. Samples for metal and inorganic parameter analysis are placed either into high-density polyethylene (HDPE) or glass bottles. 

Soil samples for VOC analysis are collected into airtight coring devices or into preserved VOA vials. Soil samples for SVOC, metal, and inorganic parameter analyses are collected into brass or stainless steel core barrel liners, acrylic liners, or into glass jars with PTFE-lined lids. The liners are capped with PTFE sheets and plastic caps. 

Example 4.3 Preparation of water samples for SVOC analysis... 

The most frequently used methods for sampling indoor surface dust for SVOC/ POM analysis is simply to use dust from a vacuum cleaner dust bag, see for example, Krause, Chutsch and Englert (1989), or a special vacuum cleaner mouthpiece containing a filter, see for example, 0ie, Hersoug and Madsen (1997). Both the mouth-piece and the filter should be cleaned prior to use. It must be assured that the SVOCs and POMs of interest are quantitatively captured by the filter (e.g., phthalates are quantitatively captured by quartz fiber filters (Clausen and Wolkoffi 1997b)) and that the vacuum cleaner exhaust does not contaminate the samples with for example, phthalates. However, the vacuum cleaner sampling method is probably very dependent on the sampling conditions (e.g., carpet or hard floor... 

To sample soil for SVOC and inorganic compound analysis, we need the following supplies and equipment ... 

Water samples are usually collected as grab samples. For regulatory compliance, as part of NPDES permits, composite samples may be required. Composite samples of water may be prepared either on a flow-proportional basis or as time composites. Water samples for VOC, SVOC, TPH and oil and grease analysis are never composited. 

For dissolved metal analysis, field filtering is essential for other analyses it may be a choice that we make based on the DQOs during the planning phase of the project. Samples for VOC or other purgeable constituent analyses are never filtered neither are, as a general rule, samples collected for SVOC analyses. If the purpose of sampling is to determine the true dissolved SVOC concentrations in groundwater versus dissolved plus colloid-transported concentrations, filtration in the field should be considered. 

Common contaminants that are sampled with wipes include dioxins/furans, PCBs, pesticides, and other SVOCs, metals, and occasionally, VOCs. Obviously, we do not expect to detect any VOCs on surfaces exposed to air, however we often sample for them to satisfy a disposal or a health and safety requirement. 

The experiments carried out diuing the January 2005 EUPHORE campaign consisted mostly of D-1, D4, D-5 and D-7 nms (Table 1). To determine the particle size, number and volume concentrations the Scanning Mobility Particle Analyzer (SMPS) was used and the particle mass was continuously monitored using TEOM. NOx and NOy species were monitored using chemiluminescence and Foiuier Transfer Infrared (FTIR) instruments. After several hours of exposure, the samples for semivolatile organic compound s (SVOC) analysis... 

We now turn our attention to sample preparation techniques to quantitatively determine volatile organic compounds (VOCs) in environmental samples, and after this, we return to a discussion of the more recently developed sample prep techniques for SVOCs. Because we have been discussing LLE and LSE techniques, it is appropriate for us to ask at this point the following question. 

Contractors at Sites B, D, G, I, and J had incomplete sampling practices and as a result were not able to evaluate PPE levels based on monitoring data. Eor example, both contractors SSAHPs at Site I lacked provisions for monitoring site hazards such as metals, pesticides, herbicides, and semi-volatile organic compounds (SVOCs) that could not be evaluated with a PID. Since worker exposures to the range of hazards on site had not been characterized, PPE was not selected based on its performance relative to the nature and level of site hazards. 

The audit team took wipe samples from the surfaee of the disearded PPE and analyzed them for metals, pestieides, and SVOCs, but found no deteetable eontamination. The Site I eontraetor, however, did not have additional sampling data from different days or varying eireumstanees to verify that on a eonsistent basis, eontamination was not being spread to elean areas of the site beeause of the laek of deeontamination operations. 

More recently, Harner et al. (2003) coated ethylene vinyl acetate (EVA) onto glass (polymer coated glass [POG]) for use as fugacity sensors or equilibrium samplers of SVOCs in indoor and outdoor air. The EVA film fhickness was 1.1 and 2.4 qm depending on the application and as expected, SVOC sorption capacity and times to equilibrium were shown to be directly proportional to film thickness. The clearance capacity Ey volume of sample medium cleared of chemical) of a sorbent for an analyte is given by... 

The major problem during measurement of SVOCs/POMs probably is the reduction of the background level in order to have low contamination in blanks. This means that everything used for the sampling and analysis must be cleaned and the purity must be checked by analysis of blank samples. 

All kinds of building materials, furniture, textiles, computers etc. are potential sources of SVOCs/POMs and estimation of the total content in the material may be required. One reason to estimate the total or initial content is that it is an important parameter in physical based emission models for example, for phthalate emission from vinyl flooring (Clausen et al, 2007). The materials can be purchased as new, or sampled from the indoor environment under investigation. The materials should be stored in a way that preserves their content of SVOCs/POMs and prevents contamination and degradation of the materials and their content of SVOCs/POMs. The content of SVOCs/POMs in the sampled materials can be estimated by extraction (see Section 2.5.1). 

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