Environmental Technology Verification Report: PCB Detection Technology. DexsilCorporation L2000DX Analyzer

摘要

The L2000DX Analyzer (dimensions, 9 x 9.5 x 4.25 in.) is a field-portable ion-specific electrode instrument, weighing approximately 5 lb 12 oz, designed to quantify concentrations of PCBS, chlorinated solvents, and pesticides in soils, water, transformer oils, and surface wipes. The L2000DX can be operated in the field powered by a rechargeable 8-V gell cell, or in the laboratory using 120-V AC power. To prepare a sample for analysis, 5 mL of the oil is collected in a polyethylene reaction tube. Two glass ampules contained in the reaction tube are broken to introduce metallic sodium to the oil. The mixture is then shaken for 10 s and allowed to react for a total of 1 min. The sodium strips the covalently bonded chlorine atoms off the PCB molecule. An aqueous extraction solution is added to the reaction tube to adjust the pH, destroy the excess sodium and extract and isolate the newly formed chloride ions in a buffered aqueous solution. The aqueous layer is decanted, filtered, and collected in an analysis vial. The ion-specific electrode is put into this aqueous solution to measure the millivolt potential. The potential is then converted to the equivalent PCB concentration. The lowest concentration reported by the L2000DX is typically 3 ppm. The performance of a previous version of this instrument (the L2000 PCB/Chloride Analyzer) was verified by ETV for soil and solvent extracts in 1998.