Measurement of Bis(chloromethyl) Ether at the Parts per Billion Level in Air

摘要

A gas chromatographic method, utilizing mass-selective detection, is described for the measurement of bis-(chloromethyl) ether (BCME) in air. The method involves preconcentration of BCME on a porous polymer sorption tube, followed by solvent desorption and derivatization to bis(p-fluorophenoxymethyl) ether (BFPME) using p-fluo-rophenolate. The derivatization reaction is quantitative and specific, forming only one product when reacted with BCME. Laboratory validation of the procedure using sorbent tubes spiked with BCME at levels equivalent to a 10 L air sample of 0.1-2 ppb (v/v) showed that the overall method recovery is 94 ± 3%. The limit of detection under standard instrumental operating conditions is estimated to be 0.01 ppb for a 10 L air sample. Two sorbents, Tenax TA and Tenax GR, were evaluated as potential collection media for BCME. Sorbent tubes containing Tenax TA spiked with BCME were stored for up to 7 days without significant losses. In the absence of a reliable, broadly applicable,and fully validated reference method for the quantification of BCME in air, this method was validated by comparison of the results of air samples spiked with an additional known amount of BCME. The combination of chemical derivatization with the selectivedetection of characteristic derivative ions enables the method to be broadly applicable to plant atmospheres in general. The method was evaluated in three industrial plants where BCME was generated as an unwanted byproduct. No interferences were detected at any of the plants studied.