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Pesticides/PCBs Method TO-10A
<br /> 7.1.4 Particle Filter. The collection efficiency of PUF for small-diameter(0.1 to 1 µm)airborne particles
<br /> is only about 20%(7). However,most pesticides and PCBs exist in air under steady-state conditions primarily
<br /> as vapors(8). Most particulate-associated pesticides or PCBs,if any,will also tend to be vaporized from filters
<br /> after collection(9). Collocated sampling with and without a quartz-fiber pre-filter has yielded indistinguishable
<br /> results for a broad spectrum of pesticides and PCBs found in indoor air(10).
<br /> 7.1.4.1 An open-face filter may be attached to the sampling cartridge by means of a union for 1-in.
<br /> (25.4-mm)tubing.
<br /> 7.1.4.2 A 32-mm diameter quartz microfiber filter(e.g.,Palifelex(&type 2500 QAT-UP)is placed in the
<br /> open end of the union and supported by means of a screen or perforated metal plate [e.g.,a 304-stainless steel
<br /> disk, 0.0312-in. (0.8-mm) thick with 1/16-in. (1.6-mm) diameter round perforations at 132 holes per in.2
<br /> (20 holes/cm2),41% open area.]. A 32-mm Viton®O-ring is placed between the filter and outer nut to effect
<br /> a seal(see Figure 3). This filter holder is available from Supelco Park,Bellefonte,PA; SKC,334 Forty Eight,
<br /> PA; and other manufacturers.
<br /> 7.1.5 Size-Selective Impactor Inlet. A size-selective impactor inlet with an average particle-size cut-point
<br /> of 2.5 gm or 10µm mean diameter at a sampling rate of 4 L/min may be used to exclude nonrespirable airborne
<br /> particulate matter(11). This inlet,particle filter support, sampling cartridge holders are available commercially
<br /> from Supelco, Supelco Park, Bellefonte, PA; SKC, 334 Forty Eight, PA and University Research Glassware
<br /> (URG),Chapel Hill,NC.
<br /> 7.1.6 Tenax-TA. 60/80 mesh, 2,6-diphenylphenylene oxide polymer. Commercially available from
<br /> Supelco, Supelco Park,Bellefonte,PA and SKC, 334 Forty Eight,PA.
<br /> 7.2 Equipment for Analysis
<br /> 7.2.1 Gas Chromatograph(GC). The GC system should be equipped with appropriate detector(s)and
<br /> either an isothermally controlled or temperature programmed heating oven. Improved detection limits may be
<br /> obtained with a GC equipped with a cool on-column or splitless injector.
<br /> 7.2.2 Gas Chromatographic Column. As an example,a 0.32 mm(I.D.)x 30 in DB-5,DB-17,DB-608,
<br /> and DB-1701 are available. Other columns may also provide acceptable results.
<br /> 7.2.3 HPLC Column. As an example,a 4.6-mm x 25-cm Zorbax SIL or gBondpak C-18. Other columns
<br /> may also provide acceptable results.
<br /> 7.2.4 Microsyringes. 5 gL volume or other appropriate sizes.
<br /> 7.3 Reagents and Other Materials
<br /> 7.3.1 Round Bottom Flasks. 500 mL,T 24/40 joints,best source.
<br /> 7.3.2 Capacity Soxhlet Extractors. 300 mL,with reflux condensers,best source.
<br /> 7.3.3 Kuderna-Danish Concentrator. 500 mL,with Snyder columns,best source.
<br /> 7.3.4 Graduated Concentrator Tubes. 10 mL,with 19/22 stoppers,best source.
<br /> 7.3.5 Graduated Concentrator Tubes. 1 mL,with 14/20 stoppers,best source.
<br /> 7.3.6 TFE Fluorocarbon Tape. 1/2 in.,best source.
<br /> 7.3.7 Filter Tubes. Size 40 mm(I.D.)x 80 mm.
<br /> 7.3.8 Serum Vials. 1 mL and 5 mL,fitted with caps lined with TFE fluorocarbon.
<br /> 7.3.9 Pasteur Pipettes. 9 in.,best source.
<br /> 7.3.10 Glass Wool. Fired at 500°C,best source.
<br /> 7.3.11 Boiling Chips. Fired at 500°C,best source..
<br /> 7.3.12 Forceps. Stainless steel, 12 in.,best source.
<br /> 7.3.13 Gloves. Latex or precleaned(5%ether/hexane Soxhlet extracted)cotton.
<br /> January 1999 Compendium of MethodsJor Toxic Organic Air Pollutants Page 10A-5
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