U. S. EPA Method

U.S. EPA, Method SCI-Determination of Nitrogen- and Phosphorus Containing Pesticides in Ground Water hy GCj NPD, draft, Apr. 15, 1988 available from U.S. EPA Environmental Monitoring and Support Laboratory, Cincinnati, Ohio, 1988. 

Chemical compatibility and U.S. EPA Method 9090 tests must be performed on the synthetics that will be used to construct FMLs. Unfortunately, there is usually a lag period between the time these tests are performed and the actual construction of a facility. It is very rare that at the time of the 9090 test, enough material is purchased to construct the liner. This means that the material used for testing is not typically from the same production lot as the synthetics installed in the field. The molecular structure of different polymers can be analyzed through differential scanning calorimeter... 

Chemical compatibility tests using U.S. EPA Method 909040 should always be performed for hazardous waste sites, but some municipal waste sites also contain hazardous, nondegradable materials. U.S. EPA conducted a 5-year study of the impact of municipal refuse on commercially available liner materials and found no evidence of deterioration within that period. However, in a current study of leachate quality in municipal landfills, the Agency has discovered some organic chemical constituents normally found in hazardous waste landfill facilities. Apparently, small quantities of household hazardous waste enter municipal sites or are disposed of as small quantity generator wastes. As a result of these findings, U.S. EPA developed a position on the need for chemical compatibility tests for thousands of municipal waste disposal sites. 

The conditions under which the material is tested are crucial. The top of the exposure chamber must be sealed and the tank should contain no free air space. A stirring mechanism in the tank keeps the leachate mixture homogeneous and a heater block keeps it at an elevated temperature as required for the test. Stress conditions of the material in the field should also be simulated as closely as possible. The original U.S. EPA Method 9090 test included a rack to hold specimens under stress conditions but was revised when some materials shrank in the leachate. Due to the hazardous nature of the material, testing should be performed in a contained environment and safety procedures should be rigorously followed. 

Normally, the geometric mean exposure value is used, with an operator weight of 65 kg and a time period of a typical work day (5 hours) in the EEC calculation. When this is done, the safety factor for application of cyromazine on potatoes is 40. For comparison, the values by the EEC method for individual operators are presented in Table 4. All operators had large safety factors. The values were a6000 by the U.S. EPA method. In the EEC method, any AOEL value greater than 1 is considered acceptable, as the actual safety factor is built into the calculation. The U.S. EPA factors followed the same pattern of high and low values as the EEC results. 

Pickering, Q.H. and J.M. Lazorchak. 1995. Evaluation of the robustness of the fathead minnow, Pimephales promelas, larval survival and growth test, U.S. EPA method 1000.0. Environ. Toxicol. Chem. 14 653-659. 

R01027 Interlaboratory Validation Study Results for Cryptosporidium Precision and Recovery for U.S. EPA Method 1622 600R94134 Method 100.2. Determination of Asbestos Structures over 10 Micrometers in Length in Drinking Water... 

R01028 Results of the Interlaboratory Method Validation Study Results for Determination of Cryptosporidium and Giardia Using U.S. EPA Method 1623... 

Target analyte target analytes are compounds that are required analytes in U.S. EPA analytical methods. BTEX and PAHs are examples of petroleum-related compounds that are target analytes in U.S. EPA methods. 

Successful bioremediation of PAH-contaminated sites is being more frequently defined as achieving a reduction of PAHs to levels governed by the background concentrations (for example, < 2 standard deviations above background levels). Evidence for this reduction is usually offered by analytical chemistry data generated with replicate soil or water samples extracted and analyzed according to standard procedures such as GC-MS (U.S. EPA Method SW-846 8270) or HPLC (U.S. EPA Method SW-846 8310). 

U.S. EPA Method Study 14, Method 604 Phenols, Government Reports Announcements Index (GRA I), 1984. 

High performance liquid chromatography (HPLC) is a common analytical technique used to determine a wide range of organic compounds. Its application has been widespread in industries such as dyes, paints, and pharmaceuticals. More than two thirds of all organic compounds can be analyzed using HPLC methods. Its application in environmental analyses, however, has been relatively recent. Only a limited number of U.S. EPA methods are based on HPLC techniques. 

Common halogenated hydrocarbons in air can be determined by NIOSH, ASTM, and U.S. EPA methods. 

Dichlorophcnylacctic acid is recommended as a surrogate standard in the U.S. EPA Method 8151. 

Several packed and capillary columns have been reported in the U.S. EPA methods, research literature, and manufacturers product catalogs. Some common columns are described below. 

The methyl esters can be also determined by GC-FID. Using a 30 m x 0.32 mm ID x 0.25 pm (film thickness) capillary column, such as DB-1701 or equivalent, the compounds can be adequately separated and detected by FID. The recommended carrier gas (helium) flow rate is 35 cm/s, while that of the makeup gas (nitrogen) is 30 cm/min. All of the listed herbicides may be analyzed within 25 min. The oven temperature is programmed between 50 and 260°C, while the detector and injector temperatures should be 300 and 250°C, respectively. The herbicides may alternatively converted into their trimethylsilyl esters and analyzed by GC-FID under the same conditions. FID, however, gives a lower response as compared with ECD. The detection level ranges from 50 to 100 ng. For quantitation, either the external standard or the internal standard method may be applied. Any chlorinated compound stable under the above analytical conditions, which produces a sharp peak in the same RT range without coeluting with any analyte, may be used as an internal standard for GC-ECD analysis. U.S. EPA Method 8151 refers the use of 4,4,-dibromooctafluorobiphenyl and 1,4-dichlorobenzene as internal standards. The quantitation results are expressed as acid equivalent of esters. If pure chlorophenoxy acid neat compounds are esterified and used for calibration, the results would determine the actual concentrations of herbicides in the sample. Alternatively, if required, the herbicide acids can be stoichiometrically calculated as follows from the concentration of their methyl esters determined in the analysis ... 

Air analysis may be performed by U.S.EPA Method TO 13 (U.S.EPA 1988), which is quite similar to the above method. PAH-bound particles and vapors (many compounds may partially volatilize after collection) may be trapped on a filter and adsorbent (XAD-2, Tenax, or polyurethane foam), and then desorbed with a solvent. The solvent extract is then concentrated and analyzed by HPLC (UV/Fluorescence detection), GC-FID, or GC/MS (preferably in SIM mode). Because of very low level of detection required for many carcinogenic PAHs, including benzo(a)pyrene, the method suggests the sampling of a very high volume of air (more than 300,000 L). 

U.S. EPA Method TO7 describes the determination of N-nitrosodimethylamine in ambient air (U.S. EPA, 1986). The method is similar to the NIOSH method discussed above and uses Thermosorb/N as adsorbent. The air flow is 2 L/min and the sample volume recommended is 300 L air. The analyte is desorbed with methylene chloride and determined by GC/MS or an alternate selective GC system, such as TEA, HECD, or thermoionic nitrogen-selective detector. The latter detector and the TEA are more sensitive and selective than the other detectors. Therefore, the interference from other substances is minimal. Other nitrosamines in air may be determined in the same way. 

Urea pesticides are structurally similar to carbamates. Some common pesticides of this class are listed in Table 2.19.2. These substances can be determined by reverse phase HPLC method. Aqueous samples can be analyzed by U.S. EPA Method 553 using a reverse phase HPLC column interfaced to a mass spectrometer with a particle beam interface. The outline of the method is described below. 

Chlorinated pesticides in aqueous and nonaqueous matrices may be determined by U.S. EPA Methods 608, 625, 505, 508, 8080, and 8270 (U.S. EPA 1984-1994). Analysis of these pesticides requires extraction of the aqueous or nonaqueous samples by a suitable organic solvent, concentration, and cleanup of the extracts, and determination of the analytes in the extracts, usually by GC-ECD or GC/MS. These steps are outlined below. 

Most of the organochlorine pesticides listed in this chapter may be analyzed by NIOSH and U.S. EPA Methods (U.S. EPA 1984-1988, NIOSH, 1984-1989). The method of analysis, in general, involves drawing a measured volume of air through a sorbent cartridge containing polyurethane foam or Chromosorb 102. The pesticides are extracted with an organic solvent such as toluene, hexane, or diethyl ether the extract concentrated and analyzed by GC-ECD. The extract may be cleaned up by florisil to remove any interference (U.S. EPA Method 608). 

Most phenols have very low vapor pressures and are not likely to be present in gaseous state in ambient air. The particles or suspension in the air may, however, be determined by different sampling and analytical techniques. NIOSH and U.S. EPA methods discuss the analysis of only a few common phenols, which include phenol, ciesols, and pentachlorophenol. 

Alternatively, acidified DNPH coated silica gel or florisil use as adsorbent derivative analyzed by HPLC (U.S. EPA Method TO 11) recommended flow rate 500 mL/min sample volume 100 L. 

Air drawn through a midget impinger containing 10 mL of 2 N I ICl/0.5% DNPH and 10 mL isooctane the stable DNPH derivative formed partitions into isooctane layer, isooctane layer separated aqueous layer further extracted with 10 mL 70/30 hexane/methylene chloride the latter combined with isooctane the combined organic layer evaporated under a steam of N2 residue dissolved in methanol the DNPH derivative determined by reversed phase HPLC using UV detector at 370 nm (U.S. EPA Method TO-5, 1988). 

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