caa a22 4500 475823214 CHVBK 20180406123824.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1023/A:1006313021834 doi (NATIONALLICENCE)springer-10.1023/A:1006313021834 Determination of the Tropospheric Hydroxyl Radical by Liquidphase Scrubbing and HPLC: Preliminary Results [Elektronische Daten] [Xiaohui Chen, Kenneth Mopper] A preliminary study was carried out toexamine the feasibility of measuring tropospherichydroxyl radicals (OH) by liquidphase scrubbing andhigh performance liquid chromatography (HPLC). Thepotential advantages of this approach are itssimplicity, portability, and low expense. Thesampling system employs glass bubblers to trapatmospheric OH into a buffered solution of salicylicacid (o-hydroxybenzoic acid, OHBA). Rapidreaction of OH with OHBA produces a stable fluorescentproduct, 2,5-dihydroxybenzoic acid (2,5-DHBA), whichis determined by reverse-phase HPLC and fluorescencedetection. Our preliminary field results indicatethat this method is most suitable for OH measurementsin clean tropospheric air, where interferences fromother atmospheric species appear to be negligible orminor relative to polluted air. In clean air, thesampling period is about 45-90 minutes, which yieldsa detection limit of approximately 3-6 ×105 radicalscm-3. During an OHintercomparison experiment at the Caribou samplingsite in Colorado, our liquidphase scrubber method wascompared with the ion-assisted mass spectrometry (MS)method. Our results were within the same range asthose of the ion-assisted MS method (1-5 ×106 radicals cm-3) within our precision atthat time (about ±30-50%). Preliminary testsin Pullman, WA indicated that the method might alsofunction in moderately polluted air by acidifying thescrubbing solution or by adding a scavenger tosuppress interferences. In Pullman, mid-day OHconcentrations were usually in the range of 2-20 ×106 radicals cm-3. Nighttime OHconcentrations were always low, either at or slightlyabove the detection limit. Kluwer Academic Publishers, 2000 hydroxyl radical nationallicence OH nationallicence HPLC nationallicence chromatography nationallicence atmosphere nationallicence air nationallicence troposphere nationallicence determination nationallicence analysis nationallicence air scrubbing nationallicence scavenging nationallicence fluorescence nationallicence Chen Xiaohui Department of Chemistry, Washington State University, 99164-4630, Pullman, WA, U.S.A. aut Mopper Kenneth Department of Chemistry, Washington State University, 99164-4630, Pullman, WA, U.S.A. aut Journal of Atmospheric Chemistry Kluwer Academic Publishers 36/1(2000-05-01), 81-105 0167-7764 36:1<81 2000 36 10874 https://doi.org/10.1023/A:1006313021834 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1006313021834 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chen Xiaohui Department of Chemistry, Washington State University, 99164-4630, Pullman, WA, U.S.A aut NATIONALLICENCE 700 1- Mopper Kenneth Department of Chemistry, Washington State University, 99164-4630, Pullman, WA, U.S.A aut NATIONALLICENCE 773 0- Journal of Atmospheric Chemistry Kluwer Academic Publishers 36/1(2000-05-01), 81-105 0167-7764 36:1<81 2000 36 10874 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer