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~N - ~KC"iiCn SAX • PLG :~~ -,53 ~'-_-~ .-: `~ _ 500-600 mL and~be equipped to accommodate a 90-110 mm filter. 7h? devices ' contain VI70N 0-ring; which should be replaced fro gi~ently, c::!:a~,i2 >~c „~ devices known to ENA era identified in'Table 3. For th? ZHE'~0 be .aCCeptable for use, the piston within the T2E should be able to be"moved with approximately 15 psi or 1?ss. !r- it ta:<es mare pressure to move the piston, the 0-rings fn the devic=. sMuld ^? r?placed. If this does not solve 'the problem, the ZHE is unacczptabi? for 1312 analyses and the manufacturer should be contacted, The ZHE should be checked for leaks after every extraction. if th? device contains a built-in pressure gauge, pressurize the device to 50 psr, allow it to stand unattended for 1 hour, and recheck the pressure- If the device does not have a built-in pressure gauge, pressurize the device to 50 psi, subr„erge it in water, and check for the presence of air bubbles escaping from any of the fittings. If pressure is lost, check all fittings and inspect and replace 0-rings, if necessary. Retest the device. If leakage problems cannot be solved, the manufacturer should b=_ contacted. Some ZHEs use gas pressure to actuate the ZHE piston, while others use mechanical pressure (see Table 3). Nhereas the volatiles procedure (see Step 7.3} refers to pounds-per-square-inch (psi), for the mechanically actuated piston,~the pressure applied is measured in torque- inch-pounds. Refer to the manufacturer's instructions as to the proper conversion. 4.2.2 Bottle Extraction Vessel. 'dhen the sample is being eval~;atad usiny the nenvaiatile extraction, ajar with sufficient capacity to hold the sample and the extraction fluid is needed. Headspacz is allowed in this vessel. The extraction bottles may be constructed from various materials, depending on the analyses to be analyzed and the nature cf the waste (see Step 4.3.3). It is recommended that borosilicate glass bottles be used instead cf other types of glass, especially when inorganics are of concern. Plastic bottles, other than polytetrafluoroethylene, shall nct be used if organics are to be investigated. Bottles are availahle frog a number of laboratory suppliers. When this type of extraction vessel is used, the filtration device discussed in Step 4.3.2 is used for initial liquid/solid separation and final extract filtration, 4.3 Filtration Devices: It is recommended that all filtrations be performed in a hood. 4.3.1 Zero-Headspace Extraction Vessel (ZHE): When the sample is evaluated for volatiles, the zero-headspacz extraction vessel described in Step 4.2.1 is used for filtration. The device shall be capable or supporting and keeping in place the glass fiber filter and be able to withstand the pressure needed to accomplish separation (50 psi). ~V1TON9 is a trademark of Du Pont, 1312 - 2 Revision 0 November 1992 `..,