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Book Preservation of Water Samples Containing Nitroaromatics and Nitramines

Download or read book Preservation of Water Samples Containing Nitroaromatics and Nitramines written by and published by DIANE Publishing. This book was released on with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Determination of Nitroaromatic Nitramine and Nitrate Ester Explosives in Water Using SPE and GC ECD Comparison with HPLC

Download or read book Determination of Nitroaromatic Nitramine and Nitrate Ester Explosives in Water Using SPE and GC ECD Comparison with HPLC written by Marianne E. Walsh and published by . This book was released on 1998 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical method for the determination of nitroaromatic, nitramine, and nitrate ester explosives and Co-contaminants in water was developed based on SPE (solid-phase extraction) and GC-ECD (gas chromatograph-electron capture detector). Water samples are preconcentrated using either cartridge or membrane SPE followed by elution with acetonitrile. The acetonitrile extract is compatible with both liquid and gas chromatography, thereby allowing direct comparison of concentration estimates obtained by different methods of determination. Quantitative GC analyses were obtained by using deactivated direct-injection-port liners, short wide-bore capillary columns. and high linear carrier gas velocities. Recoveries from spiked samples were 90% or greater for each of the nitroaromatics and nitrate esters, and greater than 70% for nitramines and amino-nitrotoluenes. Estimates of analyte concentrations in well-water extracts from military sites in the United States and Canada analyzed by GC-ECD and the standard HPLC (high performance liquid chromatography) method showed good agreement for the analytes most frequently detected (HMX octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, RDX hexahydro-1,3,5-trinitro-1,3,5-triazine, TNT 2,4,6-trinitrotoluene, and TNB 1,3,5-trinitrobenzene). The GC method provides lower method detection limits for most analytes than HPLC, but accurate calibration is more difficult. The ultraviolet (UV) detector used for the HPLC analysis has much greater linear range than the ECD used for GC analysis. In addition. the GC instrumentation requires more care than the LC. Specifically the injection port liner must be changed frequently to maintain accurate determination of the nitramines. Because the sample preparation technique yields extracts that are compatible with both GC and HPLC analysis, confirmation of analyte presence can be obtained based on different physical properties.

Book Special Report

Download or read book Special Report written by and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 804 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Book Comparison of Cartridge and Membrane Solid phase Extraction with Salting out Solvent Extraction for Preconcentration of Nitroaromatic and Nitramine Explosives from Water

Download or read book Comparison of Cartridge and Membrane Solid phase Extraction with Salting out Solvent Extraction for Preconcentration of Nitroaromatic and Nitramine Explosives from Water written by and published by . This book was released on 1992 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Comparison of Cartridge and Membrane Solid Phase Extraction with Salting Out Solvent Extraction for Preconcentration of Nitroaromatic and Nitramine Explosives from Water

Download or read book Comparison of Cartridge and Membrane Solid Phase Extraction with Salting Out Solvent Extraction for Preconcentration of Nitroaromatic and Nitramine Explosives from Water written by and published by . This book was released on 1992 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Salting-out solvent extraction (SOE) was compared with cartridge and membrane solid phase extraction (SPE) for preconcentration of nitroaromatic and nitramine explosives from water, prior to reversed-phase high performance liquid chromatographic analysis (RP-HPLC). The procedures were compared initially using reagent grade water fortified with TNT, RDX, HMX and nine other analytes at concentrations below what could be determined without preconcentration and the results were used to estimate analyte recovery and the low concentration detection capability, as characterized by the Certified Reporting Limit (CRL). CRLs for the three procedures were comparable with values generally in the range of 0.05 to 0.30 jig/L. Percentage recoveries for the three procedures were generally greater than 90%, except for those of HMX and RDX obtained by the membrane-SPE procedure. A second comparison among the three procedures was obtained on 58 groundwater samples from the Rockeye site at the Naval Surface Warfare Center, Crane, Indiana. Results from a direct analysis procedure were compared to those from the three preconcentration techniques to estimate percent recovery of HMX, RDX and TNT for real samples. Recoveries were greater than 80% except for HMX and RDX by the membrane-SPE method. Both SPE procedures exhibited background interferences, which the authors attribute to matrix interaction with the SPE polymers. Usability of the three procedures in a production-oriented laboratory was evaluated with emphasis on solvent consumption, waste production and sample processing time. The cartridge-SPE was judged to be the least rugged of the three procedures.

Book Monthly Catalogue United States Public Documents

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1994-08 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Bibliography on Cold Regions Science and Technology

Download or read book Bibliography on Cold Regions Science and Technology written by and published by . This book was released on 1995 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: