Determination of gas phase peroxyacetic acid using pre-column derivatization with organic sulfide reagents and liquid chromatography

The first selective HPLC methods for the determination of peroxyacetic acid (PAA) in gas phase samples have been developed. PAA reacts with 2-([3-{2-[ 4-amino-2-(methylsulfanyl)phenyl]-1-diazenyl}phenyl]sulfonyl)-1-ethanol (AD S) to form the corresponding sulfoxide. Sampling may be performed in imping ers using aqueous solutions of the reagent or by test tubes with the reagen t coated on a solid sorbent. Sulfide and sulfoxide are separated by means o f HPLC and detected at a wavelength of 410 nm. The method is highly selecti ve for PAA in the presence of hydrogen peroxide when sampling in impingers. A 10 000-fold excess of hydrogen peroxide leads to the same peak area comp ared to PAA. Limit of detection is 10(-8) mol PAA, thus corresponding to PA A concentration of 46 ppb when using a sampling time of 10 min with a flow- rate at 500 ml/min. Another sulfide reagent, methyl-p-tolyl sulfide (MTS) h as been used in a similar way with impinger sampling. Major advantages of A DS towards MTS are improved UV-Vis spectroscopic properties and reduced vol atility. (C) 1999 Elsevier Science B.V. All rights reserved.