EPA Method 8332 Nitroglycerine by High Performance Liquid Chromatography - Revision 0
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47BB8D42B6C94B879C31ED586809D3A7 |
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0.03 |
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8 |
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日期： |
2003-1-16 |
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CD-ROM 8332 - 1 Revision 0,December 1996,METHOD 8332,NITROGLYCERINE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY,1.0 SCOPE AND APPLICATION,1.1 Method 8332 is used to determine the concentration of nitroglycerine (CAS No. 55-63-0),in aqueous matrices such as waste water, groundwater, and surface water. This method may also,be applicable to other matrices. Method 8332 also provides a qualitative procedure for determining,the presence or absence of nitroglycerine (See Appendix A).,1.2 This method is restricted to use by, or under the supervision of, analysts experienced in,the use of HPLC instrumentation and skilled in the interpretation of HPLC chromatograms. Each,analyst must demonstrate the ability to generate acceptable results with this method.,2.0 SUMMARY OF METHOD,2.1 Samples are injected onto a reverse phase high performance liquid chromatograph,(HPLC) column and the nitroglycerine concentration is quantitated using a UV detector.,3.0 INTERFERENCES,3.1 Solvents, reagents, glassware and other sample processing hardware may yield discrete,artifacts and/or elevated baselines, causing misinterpretation of the chromatograms. All of these,materials must be demonstrated to be free from interferences.,3.2 If solid matrices are extracted using an ultrasonic bath as the extraction technique, the,period of extraction should not exceed 2 hours or degradation of nitroglycerine may occur.,Acetonitrile may be used as a solvent.,4.0 APPARATUS AND MATERIALS,4.1 HPLC system,4.1.1 HPLC (isocratic) - equipped with a pump, a direct injection port or 20 μL loop,injector and a 214 nm UV detector.,4.1.2 Column - Waters Radial - Pak CN, 10 μm particle size (or equivalent).,4.1.3 Confirmation columns:,LC-18 Reverse-phase HPLC column (octadecyldimethylsilyl), 250 x 4.6 mm with a 5 μm,particle size (Supelco Inc. or equivalent) using 3:2 MeOH/Water @ 1.5 mL/min.,LC-CN Reverse-phase HPLC column (cyanopropylmethylmethyl-silyl), 250 x 4.6 mm with,a 5 μm particle size (Supelco Inc. or equivalent) using 1:1 MeOH/Water @ 1.5 mL/min.,4.1.4 Integrator.,CD-ROM 8332 - 2 Revision 0,December 1996,4.2 Injection syringe.,4.3 Membrane filter - 0.45 μm,5.0 REAGENTS,5.1 Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is,intended that all reagents shall conform to the specifications of the Committee on Analytical,Reagents of the American Chemical Society, where such specifications are available. Other grades,may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its,use without lessening the accuracy of the determination.,5.2 Organic-free reagent water - All references to water in this method refer to organic-free,reagent water, as defined in Chapter One.,5.3 Acetonitrile, CH CN. 3,5.4 Nitroglycerine - "Nitrostat" tablets (nominal concentration = 0.4 mg/tablet), available from,Warner Lambert/Parke Davis. Certificate of Analysis for any current lot is available from Warner,Lambert, Lititz, Pa. (717) 626-2011.,NOTE: Alternatively, the analyst may purchase a solution of NG from a commercial,vender such as AccuStandard, New Haven, CT or Crescent Chemical Co.,Hauppauge, NY. NG SARMS may also be obtained from the Army,Environmental Center, Aberdeen Proving Ground, MD.,5.5 HPLC mobile phase eluant - 60% Acetonitrile/40% Organic-free reagent water.,5.6 HPLC calibration standards - Dissolve five nitroglycerine tablets in the HPLC mobile,phase, using a 500 mL volumetric flask. Dilute to volume with mobile phase. The resulting standard,will contain 4 mg/L nitroglycerine; 8 mg/L and 12 mg/L nitroglycerine standard solutions can be,prepared in the same manner. Other concentrations, as needed, can be prepared by appropriate,dilutions. Use the concentration listed on the "Nitrostat" Certificate of Analysis to calculate the,concentration of the standards to three significant figures.,6.0 SAMPLE COLLECTION, PRESERVATION, AND HANDLING,6.1 See the introductory material to this chapter, Organic Analytes, Sec. 4.1.,7.0 PROCEDURE,7.1 Chromatographic Conditions (Recommended):,Flow rate: 1.0 mL/min.,UV Detector: 214 nm.,Injection: 20 μL (for 4 to 12 mg/L nitroglycerine).,Chromatographic conditions should be established to give a retention time for nitroglycerine,of approximately 5.1 min.,CD-ROM 8332 - 3 Revision 0,December 1996,7.2 Initial Calibration - Prepare a 5-point calibration curve and establish the calibration range,of the method (nominally between 4 mg/L and 12 mg/L). Calculate a correlation coefficient, slope,and zero intercept from the regression analysis of the data points (peak area vs. concentration).,7.3 Samples should be diluted 1:1 with aceto……
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