High-volume sampler, particulate

The particles most likely to cause adverse health effects are the fine particulates, in particular, particles smaller than 10 p and 2.5 mm in aerodynamic diameter, respectively. They are sampled using (a) a high-volume sampler with a size-selective inlet using a quartz filter or (b) a dichotomous sampler that operates at a slower flow rate, separating on a Teflon filter particles smaller than 2.5 mm and sizes between 2.5 mm and 10 mm. No generally accepted conversion method exists between TSP and PM,o, which may constitute between 40% and 70% of TSP. In 1987, the USEPA switched its air quality standards from TSP to PMk,. PM,q standards have also been adopted in, for example, Brazil, Japan, and the Philippines. In light of the emerging evidence on the health impacts of fine particulates, the USEPA has proposed that U.S. ambient standards for airborne particulates be defined in terms of fine particulate matter. 

High-volume sampler A device used for extracting particulates from the air for analysis that requires a shorter. sampling period than a low-volume sampler. 

Flg ire 8.29 Apparatus for siunpling airborne organic samples. A, trapping of organic volatiles in air using a sorbent trap B, thermal desorption chamber C, high-volume sampler for air particulates. 

Jutze, G. A., and K. E. Foster (TR-2 Air Pollution Measurements Committee). Recommended standard method for atmospheric sampling of fine particulate matter by filter media—high-volume sampler. J. Air Pollut. Control Assoc. 17 17-25, 1%7. 

It should be noted that the sampler used in the study, (a stacked filter unit), collected only particles less than 15pm aerodynamic diameter, i.e. particles of respirable size. State standards for TSP are based on High Volume samplers which have no inlet cutoff. Hence, particles as large as 100 microns can be captured by these instruments. Therefore, measurements made in this study may not indicate whether particulate standards have been violated, since a significant portion of the total suspended particulate mass is not measured by the stacked filter unit (SFU). 

Fitz, D. R., G. J. Doyle, and J. N. Pitts, Jr., An Ultra-High Volume Sampler for the Multiple Filter Collection of Respirable Particulate Matter, J. Air Pollut. Control Assoc., 33, 877-879 (1983). 

The protocol focuses on the preparation of collected particulate samples and provides guidance in the selection of a suitable collection technique. Particulate collection methods were not specified because the selection and implementation of those methods are source-dependent. Potential air-sampling techniques include the standard high-volume (Hi-Vol) samplers (4), massive-volume samplers (5), medium-volume samplers, low-volume samplers, and ultra-high-volume samplers (6). 

Another problem encountered was the impurity content of the filter paper used in the high volume samplers to collect the particulate samples. The conventional filter material used by EPA was glass fiber filter media. However, this was not compatible with INAA because of its high and varied impurity content. Discussions with K. Rahn of the Ford Reactor at the University of Michigan revealed that Whatman-41 filter paper was the most desirable medium for use with INAA (see Ref. 2). Our analyses showed Whatman-41 to be very low in impurities with consistent impurity levels from batch to batch. Average impurity levels, based on 12 batch analyses, are shown in Table III. Although the levels for calcium, chlorine, sodium, aluminum, and iron appear large, they rarely affected elemental levels found in filtered particulates. Impurity levels did not vary more than 25% from the mean. 

For this reason, particulate samplers designed for particulate removal have to generate the maximum possible particulate mass. Modern examples include impactors based on the high-volume sampler (Hi-Vols), the MOUDI (17) of the University of Minnesota, and the BLPI (16). The Hi-Vols, in particular, collect 330 m3 of air in 4 h, giving 1100 xg of deposit for three size cuts below a particle diameter of 2.5 xm. Table I shows some key parameters for a few widely used ambient air impactors for multiple size cuts. 

A high-volume sampler equipped with a size selective inlet and a quartz fibre filter was used to collect particulate matter less than or equal to 10 pm in diameter, PMi0 (Figure 1) [ ] ... 

The high-volume sampler has become the most widely used tool for monitoring particulate matter air pollution. It is a low-cost, portable, easily maintained, and reasonably precise sampling device. Improvements in sampler performance have resulted from incorporation of automatic timers, flowrate recorders, and size separation devices into the basic system. Although hi-vols are the accepted standard in particulate matter monitoring, they inherently lack the ability to provide realtime particulate matter measurements. 

Disadvantages of high-volume samplers are High power consumption, high noise production and in some cases contamination of the particulate samples by abrasion products of the pump have been reported (Countess 1974). 

Standard Practice for Application of the Hi-Vol (High-Volume) Sampler Method for Collection and Mass Determination of Airborne Particulate Matter, D4096, in Annual Book of ASTM Standards, Vol. 11.03, Philadelphia, PA, American Society for Testing and Materials (1983)... 

In a reeent paper, partieulate matter samples are colleeted using another type of high volume sampler an impactor in whieh polyurethane foam (PUF) or polypropylene foam are used as the polymer substrates (Sun et al. 2009). To quantitatively extract organic tracer eompounds from ambient particulate matter, a protocol of two extractions with isopropanol followed by three extractions with dichloromethane was developed for both substrates precleaning and analyte extraetion. 

High-Volume Sampler for Fine Particulate Matter in Gas... 

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