Sampler high volume

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. 

Brown and coworkers (18,35) used X-ray fluorescence to analyze the elemental composition of total dusts from five cottonseed oil mills. The dusts were removed from high volume samplers by forceps followed by brushing. Samples from cleaning, delintering, hulling and baling areas were taken. A summary of the data is shown in Table XIV. Silicon is the most abundant element detected in all areas except hulling. 

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. 

HPLC methods with fluorescence detection have also been developed for the determination of nitro-policyclic aromatic hydrocarbons (PAHs) (among which 9-nitroanthracene and 1-nitronaph-thalene) [238] in atmosphere. Samples have been collected in a standard high-volume sampler with a Teflon-coated glass fiber filter, and the Soxhlet extraction was performed with dichloromethane as the solvent. RP HPLC/UV techniques are used for the determination of aldehydes, ketones, and carbonylic compounds after derivatization with DNPH [239],... 

Figure 6. Mass fraction of organic (-0-) and elemental (— —) C in Detroit, Ml—aerosol in 1975. Mass is the total mass concentration of aerosol as measured by a high-volume sampler r is the correlation coefficient between organic and elemental mass fractions fr = 0.60).

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. 

Qualitative evidence of the possible influence of pressure drop can be seen by comparing recoveries of carbonaceous material, as carbon, while varying filter sampling flow rates. For example, samplers operating at a face velocity (i.e., flow rate per unit area of the macroscopic filter surface) of 11 cm/s yielded an average of 30% greater total carbon, in xg/m3, compared to a standard high-volume sampler operated at 50 cm/s (67). 

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) [ ] ... 

Figure 2. Calibration curve for the high-volume sampler (c=-0.06 0.19in d=9.62 0.24).

A very low detection limit, >1 ng/m3 may be achieved using a 24-h sampling period, sampling over 5000 L ambient air. Such a high volume sampler consists... 

Pan et al. (1999) reported detailed observations of PAH decay in aerosols under UV light of 253.7 nm. The study used a high volume sampler to collect the total suspended particles in air with quartz filters as the supporter. The results showed that the photo degradation of PAHs under UV radiation took place immediately, and was a first-order reaction. The photodegradation rate constant (k) is related to the oxidation half-wave potential (Ei/2) and the structure of the PAHs. 

Aerosol samples were taken weekly over a period of one year from May 1984 to June 1985 on the North Frisian island of Pellworm (Germany) which is not polluted by defined emitters. The high volume sampler used was equipped with a five-stage slotted... 

No firm conclusions can be reached concerning detection limits with the resins or foam, since these vary so much with the rigor of cleanup, the chemicals tested, and the particular air environment. It appears, however, that both materials can achieve detection limits of 0.01 ng/nr under the most favorable conditions when employed in high-volume samplers, while the limit for the glycol impingers is on the order of 0.1 ng/m ... 

Compton, B. Bjorkland, J. Design of a high-volume sampler for airborne pesticide collection. Presented at the 163rd National Meeting of the American Chemical Society (PEST 021), Boston, Mass. April, 1972. 

The aldehyde is trapped with high volume samplers suspended in mid-canopy drawing 25 - 30 m /hr of air through a bed of 20 g of Amberlite XAD-2 resin. Originally the pheromone was derivat-ized to the pentafluorobenzyl oxime after solvent extraction from the resin (8). This was followed by silica gel column clean-up and quantitation by capillary GC with electron capture detection. This gave satisfactory results but was tedious and expensive. 

A high-volume sampler has an airflow rate of 30 ft3/min. Design a horizontal elutriator (settling chamber) that could be placed upstream from the sampler to eliminate those particles greater than 10 pm in diameter. Assume a particle specific gravity of 2.3. What diameter particles would be reduced by a factor of 50 percent in this unit ... 

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