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Is My Drywall Chinese? - HB Litigation Conferences

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Reduced Sulfur Compounds<br />

are Difficult to Sample and Analyze<br />

• Reactivity‐‐Decomposes easily…reactions with<br />

other analytes (e (e.g, g water) or with surfaces<br />

• Adsorptivity‐‐H2S binds to metal surfaces<br />

(except gold)<br />

• Diffusivity—Losses through container (e.g.,<br />

Tedlar bag)<br />

• Analysis—to get high sensitivity and<br />

specificity, need dedicated and specialized<br />

equipment<br />

Air Methods—Whole Air<br />

• No ‘official’ method for low‐level ambient RSC<br />

• NIOSH/OSHA Methods—occupational, ppmv levels<br />

• Methods are adopted and/or modified—e.g., ASTM‐<br />

5504: Standard Test Method for Determination of<br />

Sulfur Compounds in Natural Gas and Gaseous Fuels by<br />

Gas Chromatography and Chemiluminescence<br />

• EPA Compendium Method TO‐15—for VOCs, but some<br />

labs do use it. Problems with metal surfaces<br />

• General bag methods—Tedlar, Teflon, <strong>My</strong>lar, Saran,<br />

Flexfoil, etc. All suffer rapid losses.<br />

6/23/2009<br />

4

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