MEASUREMENT OF BIS(CHLOROMETHYL) ETHER AT THE PARTS-PER-BILLION LEVELIN AIR

A gas chromatographic method, utilizing mass-selective detection, is d escribed for the measurement of bis(chloromethyl) ether (BCME) in air. The method involves preconcentration of BCME on a porous polymer sorp tion tube, followed by solvent desorption and derivatization to bis(p- fluorophenoxymethyl) ether (BFPME) using p-fluorophenolate. The deriva tization reaction is quantitative and specific, forming only one produ ct when reacted with BCME. Laboratory validation of the procedure usin g sorbent tubes spiked with BCME at levels equivalent to a 10 L air sa mple of 0.1-2 ppb (v/v) showed that the overall method recovery is 94 +/- 3%. The limit of detection under standard instrumental operating c onditions is estimated to be 0.01 ppb for a 10 L air sample. Two sorbe nts, Tenax TA and Tenax GR, were evaluated as potential collection med ia for BCME. Sorbent tubes containing Tenax TA spiked with BCME were s tored for up to 7 days without significant losses. In the absence of a reliable, broadly applicable, and fully validated reference method fo r the quantification of BCME in air, this method was validated by comp arison of the results of air samples spiked with an additional known a mount of BCME. The combination of chemical derivatization with the sel ective detection of characteristic derivative ions enables the method to be broadly applicable to plant atmospheres in general. The method w as evaluated in three industrial plants where BCME was generated as an unwanted byproduct. No interferences were detected at any of the plan ts studied.