%PDF-1.4 % 5 0 obj << /S /GoTo /D (abstract.1) >> endobj 8 0 obj (Abstract) endobj 9 0 obj << /S /GoTo /D (section.1) >> endobj 12 0 obj (Introduction) endobj 13 0 obj << /S /GoTo /D (section.2) >> endobj 16 0 obj (Methods) endobj 17 0 obj << /S /GoTo /D (subsection.2.1) >> endobj 20 0 obj (Reagents and sample preparation) endobj 21 0 obj << /S /GoTo /D (subsection.2.2) >> endobj 24 0 obj (Absorptivity) endobj 25 0 obj << /S /GoTo /D (subsection.2.3) >> endobj 28 0 obj (Atmospheric pressure chemical ionization mass spectrometry) endobj 29 0 obj << /S /GoTo /D (section.3) >> endobj 32 0 obj (Results and discussion) endobj 33 0 obj << /S /GoTo /D (subsection.3.1) >> endobj 36 0 obj (General absorbance and mass spectral characteristics) endobj 37 0 obj << /S /GoTo /D (subsection.3.2) >> endobj 40 0 obj (Pyrazine-based chromophores) endobj 41 0 obj << /S /GoTo /D (subsection.3.3) >> endobj 44 0 obj (Role of pH in chromophore formation) endobj 45 0 obj << /S /GoTo /D (subsection.3.4) >> endobj 48 0 obj (Role of evaporation in chromophore formation) endobj 49 0 obj << /S /GoTo /D (section.4) >> endobj 52 0 obj (Conclusions) endobj 53 0 obj << /S /GoTo /D (dataavailability.1) >> endobj 56 0 obj (Data availability) endobj 57 0 obj << /S /GoTo /D (authorcontribution.1) >> endobj 60 0 obj (Author contributions) endobj 61 0 obj << /S /GoTo /D (competinginterests.1) >> endobj 64 0 obj (Competing interests) endobj 65 0 obj << /S /GoTo /D (acknowledgements.1) >> endobj 68 0 obj (Acknowledgements) endobj 69 0 obj << /S /GoTo /D (biblio.1) >> endobj 72 0 obj (References) endobj 73 0 obj << /S /GoTo /D [74 0 R /Fit ] >> endobj 112 0 obj << /Length 3764 /Filter /FlateDecode >> stream xڭn]_1/(@C>)^x7Z[}X硇liIק&9# uwUuWqۼx~{uor7Ods{#7σMnrs=4q/A9/2v{C? ÏA\o;\0%7,k%|;]WlzTdPԍSA"ଛTN 6+{T۪=߈yHfd~ؑ\*y>>Rfi%t'sqהgnQw7P4 HyXD5a=Z75P/_Ԫ c_s3flق"ހ˯ <7D^tkzTH- Ah+> \o W#y4$[Ȝׅ^'qNvTSim2h; \Iyw6+~뽦{TfZel+\>gޏf8fՕ/ά[r?|IT~ߑU3}G}u7"e\]'} yB"}2@]ߡsC4t.Z3B5c".5EeE[LQ_{6QX#W9VE~n]NeEtup`db7p?ۺiqz0H*q~`2Sh'˱^kt!C" /[}pJG}g:N$t9I7({%`R-*v/v^#$ɯ8"Z[(@=Fc1n>Z]bhA8'AtpiĀ}yl}Uη#Qu kg8?+_E=mDDTt́UYz!96sp QWhRWߔ AK rO#乄Iz>A\]tP2>0fЍa9vP) >2Až-P7ho[nΛ9obăfy&e6OB$m:)Q>!ʗ @P{n@H*Ebhɀa5>Ύ վ,8N pL $'X}0' EΔ$r"zøngKsuA\۲>*>")Ct/n,o.naU LtvVzѪ,+ւ0X"S_ Ǘ@T/f69Qx[sDX@2,uj@c),΄ũ0ZZ,cЫw%C)%ĀLu~2l#E#(A(J"`Y 8b'ef!h"ݓ-a9"~z zeF^ဏ<>/˹a.oY=(at :pfB BCJB|1 'ưD-FA03C0V;qhڧaGf["($RYcR{noӓr0Oq c5 t?qV6R֫G26 C"E2[sjn-q^h'XI4dO{SHJ*pZPˆm%.[lCȊF{)ѱ(b@m9 !{n!쩀z7ZzDrНf f)RbVb'$@БB?8mv=C7 _UW$Q&{!BR$6閻4.ER