EPA Method 1312 Synthetic Precipitation Leaching Procedure
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ID： |
DBFAEEC81FC9436496B9F6F97CA49F3F |
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文件大小(MB)： |
0.79 |
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页数： |
30 |
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文件格式： |
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日期： |
2005-8-11 |
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购买： |
文本摘录（文本识别可能有误，但文件阅览显示及打印正常，pdf文件可进行文字搜索定位）：
CD-ROM 1312 - 1 Revision 0,September 1994,METHOD 1312,SYNTHETIC PRECIPITATION LEACHING PROCEDURE,1.0 SCOPE AND APPLICATION,1.1 Method 1312 is designed to determine the mobility of both organic,and inorganic analytes present in liquids, soils, and wastes.,2.0 SUMMARY OF METHOD,2.1 For liquid samples (i.e., those containing less than 0.5 % dry,solid material), the sample, after filtration through a 0.6 to 0.8 μm glass fiber,filter, is defined as the 1312 extract.,2.2 For samples containing greater than 0.5 % solids, the liquid phase,if any, is separated from the solid phase and stored for later analysis; the,particle size of the solid phase is reduced, if necessary. The solid phase is,extracted with an amount of extraction fluid equal to 20 times the weight of the,solid phase. The extraction fluid employed is a function of the region of the,country where the sample site is located if the sample is a soil. If the sample,is a waste or wastewater, the extraction fluid employed is a pH 4.2 solution.,A special extractor vessel is used when testing for volatile analytes (see Table,1 for a list of volatile compounds). Following extraction, the liquid extract,is separated from the solid phase by filtration through a 0.6 to 0.8 μm glass,fiber filter.,2.3 If compatible (i.e., multiple phases will not form on combination),the initial liquid phase of the waste is added to the liquid extract, and these,are analyzed together. If incompatible, the liquids are analyzed separately and,the results are mathematically combined to yield a volume-weighted average,concentration.,3.0 INTERFERENCES,3.1 Potential interferences that may be encountered during analysis are,discussed in the individual analytical methods.,4.0 APPARATUS AND MATERIALS,4.1 Agitation apparatus: The agitation apparatus must be capable of,rotating the extraction vessel in an end-over-end fashion (see Figure 1) at 30,+ 2 rpm. Suitable devices known to EPA are identified in Table 2.,4.2 Extraction Vessels,4.2.1 Zero Headspace Extraction Vessel (ZHE). This device is for,use only when the sample is being tested for the mobility of volatile,analytes (i.e., those listed in Table 1). The ZHE (depicted in Figure 2),allows for liquid/solid separation within the device and effectively,precludes headspace. This type of vessel allows for initial liquid/solid,1VITON?is a trademark of Du Pont.,CD-ROM 1312 - 2 Revision 0,September 1994,separation, extraction, and final extract filtration without opening the,vessel (see Step 4.3.1). These vessels shall have an internal volume of,500-600 mL and be equipped to accommodate a 90-110 mm filter. The devices,contain VITON?1 O-rings which should be replaced frequently. Suitable ZHE,devices known to EPA are identified in Table 3.,For the ZHE to be acceptable for use, the piston within the ZHE,should be able to be moved with approximately 15 psig or less. If it,takes more pressure to move the piston, the O-rings in the device should,be replaced. If this does not solve the problem, the ZHE is unacceptable,for 1312 analyses and the manufacturer should be contacted.,The ZHE should be checked for leaks after every extraction. If the,device contains a built-in pressure gauge, pressurize the device to 50,psig, 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 psig, submerge 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 O-rings, if necessary. Retest the,device. If leakage problems cannot be solved, the manufacturer should be,contacted.,Some ZHEs use gas pressure to actuate the ZHE piston, while others,use mechanical pressure (see Table 3). Whereas the volatiles procedure,(see Step 7.3) refers to pounds-per-square-inch (psig), for the,mechanically actuated piston, the pressure applied is measured in torqueinch-,pounds. Refer to the manufacturer's instructions as to the proper,conversion.,4.2.2 Bottle Extraction Vessel. When the sample is being,evaluated using the nonvolatile extraction, a jar with sufficient capacity,to hold the sample and the extraction fluid is needed. Headspace is,allowed in this vessel.,The extraction bottles may be constructed from various materials,depending on the analytes to be analyzed and the nature of the waste (see,Step 4.3.3). It is recommended that borosilicate glass bottles be used,instead of other types of glass, especially when inorganics are of,concern. Plastic bottles, other than polytetrafluoroethylene, shall not,be used if organics are to be investigated. Bottles are ava……
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