Document Yr8643xvD2peOzJRwq1njZeNO

AR226-3360 > ATMOMSPEHCAEHLRACINCOISHLMOIFSLESOTFCIMnFFEL2SnU+1OACNRHDO2CTDHEE2LGOORHMAEDRATION Valrie Bossoutrot*, Tanya Kelly#, Isabelle Magneron*, Wahid Mellouki*, Howard Sidebottom#, Klaus Wirtz and Georges Le Bras* * LaCbe*onrCtarthooeidmreeiEsdtsertyuCdDoimeopsbaAurtsmmtiboeinnetn,ettUaSlneyisvstedremslietMyseRCdoiatlelcertrgifesn,,eDCou,NbVRliaSnleO(nIcRrliLaa)(nSsP()F) SETAC Prague 18-22 April 2004 Context : Long chain perfluorinated carboxylic acids (PFCAs, CnF2n+1C(0)0H, n = 6-12) oPbFseCrAvesd:innfoisthgaenndermaallmymusaelsd directly in consumer or industrial m- parteesruimalasbly degradation products of precursor chemicals : potentially FTOHs Fluorotelomer alcohols (FTOHs, CnF2n+1CH2CH2OH) : --UPsreosd:uicnttieornm: e5dxi1a0te6skignymra1n(u(82f0a0%c%tupnroeolynomfpdoeirlvyicemraseperpipclricoadtuiocntss)) -- AOtbmseorsvpehdeirnicthsoeuartcmesos:pdheegrread(uaptioton 1o35poplgymnre3r) and non polymeric materials - EthxapteicntceodrtpoorpaatretiFtiToOn Hinsto(?th) e atmosphere (low water solubility, high vapor pressure) Assessment of environmental impact of FTOHs requires information concerning their atmospheric persistence and degradation products This work - Rate constants for the reactions : OH + 3,3,3 trifluropropanol (CF3CH2CH2OH) OH + tridecafluorooctanol (C6F13CH2CH2OH) OH + 3,3,3 trifluoroplropanal (CF3CH2CHO) => persistence :T= 1/k [OH] - DegradaotifoCnFp3rCoHdu2CctHs 2oOfHtheinOaHir- and Cl-initiated oxidation Experimental methodology - Rate constant measurements F- ERPelacthiavmeHbrae2tr0es2s(t+5u0dliiagenhsdt:(125504Ln)mir)ra--d>i2ateOdHby lamps : or 0O3C+Dl)ig+htH(22054 nm2)O-H> O (lD) + 0 2 P- uAlbsesodlluatseerraptehosttoudlyiessis-:laser induced fluorescence H20 2+ light (248 nm) -> 2 OH - -PFrEoPducchtasmtubdeiress(50 and 150 L) GC and FTIR analysis of reactants and products after sampling - Outdoor chamber EUPHORE (200 m3) HONO + light ( >300nm) -> OFI + NO C1C(0)C(0)C1 + light (> 300 nm) - 2 CO + 2 Cl In situ FTIR analysis of reactants and products Concentration-time profiles for the reaction of OH radical with CF3CH2CH'J2OH and various reference compounds at 298 K. OH + CF3CH2CH2OH Products OH + Reference -->Products k, kj ln([CF3CH2CH2OHl0/[CF3CH2CH2OH]t) = k2/k2lnaReferenceyfReference],) kt = (1.08 0.04) x 1012cm3molecule's-1 Absolute rate constant measurements for the reaction of OH radical with CF3CH2CH2OH and CF3CH2CHO at 298 K. OH + CF3CH2CH2OH -> Products OH + CF3CH2CHO Products k3 k3 k' = k, [CF3CH2CH2OH] + k(/ or k' = k3[ CF3CH2CHO] + k(/ kj = (0.89 0.03) x 1012 cm3molecule1s 1 k3= (2.96 0.04) x 1012 cm3molecule1s_1 Rate constant for the reaction of OHTadical with C6F13CH2CH2OH (TDO) using the relative rate method Reference Compound n-hexane Analytical technique FTIR GC-FID FTIR GC-FID ^^TDO ^R ef 0.15 0.01 0.26 0.02 0.17 0.02 0.21 0.02 (10_12cm3^mToDOlecule1s 1) 0.820.08 1.42 0.15 0.93 0.14 1.14 0.14 n-butyl formate FTIR GC-FID FTIR GC-FID 00..2229 00..0012 0.27 0.03 0.24 0.05 01..7083 00..1252 00..8956 00..3205 k = (0.99 0.18) x 1012cm3molecule1s 1at 298K Rate constant data and atmospheric lifetimes (IO-12 cm3mk olec.`1s_1) T([O=Hd1a/]ky=s[O10H6]) CF3CH2CH2OH c6f 13ch2ch2oh c f3ch 2cho - 1.0 - 1.0 ~ 3.0 - 12 - 12 ~4 => Length(inofaCgrneFe2mn+1engtrowuipthhEasllinsoeitmalp.aEcSt Ton2t0h0e3r,e3a7c,ti3v8it1y6o) f FTOHs f =* k (OH + CnF2n+1CH2CH2OH) = IO12 T(CnF2n+1CH2CH2OH) = 12 days Product study Concentration-time profiles of reactants and products from the reaction of Cl-initiated oxidation of CF3CH2CH2OH in air at EUPHORE. CF3CH2CH2OH CF3CH2CHO CF3CHO cf2o Product yield plot for the Cl-initiated oxidation of CF3CH2CH2OH in air at EUPHORE (absence of NOx). In experiments carried out in the presence of NOx, small amount of peroxyacyl nitrate CF3CH2C (0)02N 02was also produced ##m Concentration-timeprofilesfor the OH-initiated oxidation of CFsCH2CH2OH in air in thepresence ofN0Xat EUPHORE. Photolysis time minutes ! Product yield plot for the OH-initiated oxidation of CF3CH2CH2OH in air in the presence of NOxat EUPHORE -A [CF3CH2CH20H] ## -inEtxhpeelraimboernattsoroynpChlo-toanredacOtoHr-singiativaetesdimoixliadradtiaotna aosf aCtFE3UCHPH2COHR2EO.H in air carried out -asEtxhpeeprirmimeanrtys opnroCdlu-catnwditOhHa-yinieitlidatceldosoextiodautnioitny.of CF3CH2CHO showed CF3CHO The present product study has shown that: - CF3CH2CHO is the only product (unity yield) of the Cl- and OH-initiated oxidation of CF3CH2CH2OH, in the absence or presence of NOx i-nCtFh3eCaHbOseniscethoefmNOajxoranpdroadyuicetldofotfh.8e5d+eg/-r0a.0d5atiinonthoefpCrFes3eCnHce2CoHf NOO, wxith a yield of unity - These data are consistent with those of Hurley et al. J.Phys. Chem. A 2004, 108, 1973 Oxidation mechanism of CF3CH2CH2OH OH/(Cl) + CF3CH2CH2OH -> CF3CH2CHOH + H20/(HC1) c f3ch 2c h o h + 0 2-->c f3ch 2cho + h 2o OH/(Cl) + CF3CH2CHO CF3CH2C(0) + h 2o CF3CH2C(0) + 0 2+ M CF3CH2C (0 )0 2 +R 0 2 CF3CH2C(0)0 cf3c h CF3CH2C ( 0 ) 0 2C+F3cCoH22C (0 )0 2+ M +ro +o2 CF3CH2+ 0 2+ M - CF3CH20 2+ M CF3CH20 2+ R02 CF3CH20 + ro + o2 CF3CH20 + 0 2 CF3CHO + H02 In thepresence ofNOx CF3CH2C(0)02+ NO ^ CF3CH2C(0)0 + n o 2 c f3ch 2o2+ no -> c f3ch 2o + n o 2 CF3CH2C(0)02+ N 02+ M CF3CH2C(0)02N 02+ M 0H/(C1) + cf3cho (+ o 2) CF3C(0)02+ H20/(HC1) CF3C CF3C (0 (0 )0 )0 2->+RC0F32+cCoF23C (0)0 + RO + 0 2 CF3+ 0 2+ M CF30 2+ M cf3o2+ ro 2-h>c f3o + ro + o2 cf3o CF20 In thepresence ofNOx: CF3C(0)02+ NO -> CF3C(0)0 + n o 2 cf3o2+ n o c f3o + n o 2 ' CF30 + NO -> CF20 + FNO CFaC(0)02+ NOz+ M CF3C(0)02N 02+ M Atmospheric implications - CF3CH2CH2OH CF3CH2CH2OH will be removed by OH (x ~ 12 days) CF3CH2CHO produced will be removed mainly by OH (x ~ 4 days). Photolysis is a minor process (x > 15 days, Sellevag et al PCCP 2004, 61243) In the presence ofNOx, small amount of CF3CH2C(0)02N 02will be formed In the absence ofNOxcarboxylic acid could be formed: CF3CH2C(0)02+ H02-> CF3C(0)0H + 0 3 Yield of -25% (Sulbaek et al Chem. Plays. Lett. 2003, 381, 14) CF3CHO will be the major oxidation product. It will be removed by OH (x * 25 days) and possibly photolysis (x > 27 days, Sellevag et al 2004% and may be uptaken by water (-rOaiHn arneadcctiloonudw):ill produce CF20 and peroxynitrate in the presence ofNOx, and could be a source of trifluroacetic acid at low NOx: CF3C(0)02+ H02-->CF3C(0)0H + 0 3 - Photolysis is likely to produce CF3which will yield CF20 - Uptake by water is a source of CF3COOH Atmospheric implications Long chain FTOHs FTOHs will be removed by OH (x ~ 12days) PChnFo2ton+ly1CsiHs 2wCoHuOldpbreodauscloedweisr epxropceecstesd(ftroobmeerxempeorivmedenbtys aOtHEUlikPeHCOFR3EC)H2CHO (x ~ 4 days). ICYni,,eFthl2den +u1anbCksnHeon2wcCen(o0f)N0 2O+xHca0rb2o-xylCicnFa2cni+d1CcoHu2lCd(b0e)0foHrm+ed0:3 C(U-xO,,p=FtHa22nkr5+ee|CadbcHaytyiOwso,nawftrweooriumlsllhdpSobruuoelldbdtuahbeceekemiCenatFsjaio2gl0rn2oi0afx0niicd3da)anptateinor(odnloxlpnyirgkaoeccdlyhyulacnbitiny.trIapatlthwdeoeiithlnolylbtydheseeisrspea{mrrreeaosetfveaneicudrelnybkoynufonONwsHoOnl)xu.,balen)d could be aC-YPi,,seFohl2udonrt+uco1nelCykos(nif0osc)wia0snr2bli+okxeHylyl0ict2oa-pcridoCdanutFcl2eon+wC1CnNF(O20n)+xO1: wHh+ic0h 3 will yield CF20 =O>HTrheeacctaiopnac/pithyootoflFysTiOs rHastetoraftoiormanPdFyCieAldsswoifllPnFeCedAlsofwroNmOpxecrooxnyceancytrla+tioHnOazndrewacitlilodne,pwenhdicohn remain to be determined. I Acknowledgments Total company (D r Jean M arie Libre) and Telomer Research Programme fo r support F