Light-Source-Dependent Effects of Main Water Constituents on Photodegradation of Phenicol Antibiotics: Mechanism and Kinetics Linke Ge, Jingwen Chen, * Xianliang Qiao, Jing Lin, Xiyun Cai Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), Department of Environmental Science and Technology, Dalian University of Technology, Linggong Road, Dalian 1164, P. R. China 58 Pages 6 Figures 4 Tables Detailed Analytical Procedures A Shimadzu TOC-V CPH analyzer was employed to determine total organic carbon (TOC) contents. Conductivity and ph were determined by a DDS-11A conductivity meter coupled with a DJS-1 electrode and a Leici model PHS-3C ph meter coupled with an E-1-C probe, respectively. UV vis absorption spectra of thiamphenicol and florfenicol were recorded using a Hitachi U-8 spectrophotometer (Figure 1). An Agilent 11 HPLC with Hypersil C18 reversed-phase column (5 mm 4.6 mm, 5 μm) and DAD was used to analyze the concentration of thiamphenicol and florfenicol. The mobile phase was 3:7 mixture of acetonitrile and water with a flow rate of 1. ml/min. For thiamphenicol and florfenicol, the injection volume was μl and 1 μl, and detection wavelength 5 nm and 3 nm, respectively. The method detection limits of the HPLC analysis were.4.1 mg/l and the recoveries were 96.8 11.% for the phenicols in all solutions. S1
Anions were analyzed by a Shimadzu Class-VP ion chromatography (IC) coupled with a Shimpack IC-GA3 guard column (1 mm 4.6 mm), a Shimpack IC-A3 anion analytical column (15 mm 4.6 mm), and a Shimadzu SCL-1A SP non-suppressed conductance detector, and using 8 mm p-hydroxybenzoic acid (ph 4.5) as a mobile phase. Cations were monitored by an Optima DV inductively coupled plasma-atomic emission spectrometry (ICP-AES). The phenicols dissolved in pure water at concentrations up to 4 mg/l were exposed to UV-Vis irradiation (λ > nm) and sampled. Photoproducts in the samples were separated and identified with an Agilent 11 Series LC/MSD trap system using a triple quadrupole mass analyzer and working in positive and negative mode. The chromatographic separation conditions were the same as the HPLC analyses except for the ratio of mobile phases. For thiamphenicol, the gradient (acetonitrile in water) program was: 1 min, 5 4% (linear); 1 15 min, 4 6%; 15 min, 6%. For florfenicol: 5 min, 5%; 5 min, 5 4%; 3 min, 4 8%. The electrospray ionization (ESI) source with a capillary potential of 35 V was applied. The fragmentor voltage was optimized to be 5 V, and the MS scan range was m/z 5 to 1 amu. The product molecular weights were assigned on the basis of their pseudomolecular ions. The structures were identified according to their MS n mass fragmentation pattern combined with their molecular weight and parent structures. Some intermediates were tentatively characterized as isomeric compounds that possess extremely close retention time and similar mass fragmentation spectra. Electron paramagnetic resonance (EPR) combining with spin trapping was employed to identify ROS ( 1 O, OH and O - ) generated in some photodegradation solutions.,,6,6-tetramethyl-4-piperidone (TEMP, 95%, Sigma Aldrich ) and 5,5-Dimethyl-1-pyrroline-N-oxide (DMPO, 97%, Sigma Aldrich) were used as the spin traps of 1 O and OH/O -, respectively. EPR spectra were recorded at room temperature on a Bruker EMX A- spectrometer equipped with a W mercury lamp as the irradiation light source (λ > nm). When needed, the irradiation light was filtered by pyrex-glass to get λ > 9 nm light. The EPR settings were modulation frequency 1 khz, modulation amplitude. G, microwave frequency 9.4 GHz and power 5.1 mw. Identification of H O generated in the irradiated solutions was performed with a photometric method reported by Bader et al. (1). S
Table S1. Ions, TOC, conductivity and ph analysis of seawater and freshwater samples. Freshwater Seawater Na +.6 mg/l 1.13 1 3 mg/l K + 6.74 mg/l 5.38 1 mg/l Ca + 38.76 mg/l 3.16 1 mg/l Cations Mg + 15.74 mg/l 1.13 1 3 mg/l Anions Fe +.9 mg/l <. mg/l Zn +.79 mg/l.1 mg/l Cu +.1 mg/l <.1 mg/l Cl - 6.4 mg/l.43 1 4 mg/l PO 4 3- NO - /NO 3 - SO 4 - <.1 mg/l <.1 mg/l 8. mg/l 17.5 mg/l 38.8 mg/l <.1 mg/l Br - <.1 mg/l 59 mg/l HCO - - 3 /CO 3 <.1 mg/l <.1 mg/l TOC 15.3 mg C/L 3.5 mg C/L Conductivity 5.51 1 μs/cm 5.4 1 4 μs/cm ph 9.1 8.1 S3
Table S. Rate constants (k), half-lives (t 1/ ) and correlation coefficients (r ) for the photodegradation of the two phenicols under irradiation of Matrix three light sources. HA: humic acid; L-HA: local humic acid. Thiamphenicol Florfenicol k (min 1 ) ± SD r t 1/ (min) ± SD k (min 1 ) ± SD r t 1/ (min) ± SD UV vis irradiation (λ > nm) Pure water (4. ±.) 1.983.999 17 ±.8 (4.9 ±.) 1.997.999 14 ±.6 ph 4.9 (3.9 ±.3) 1.975.999 18 ± 1. (4.6 ±.4) 1.998.999 15 ± 1.1 ph 6. (3.9 ±.4) 1.976.999 17 ± 1. (4.8 ±.3) 1.997.999 14 ± 1.1 ph 7. (3.9 ±.3) 1.976.999 18 ± 1. (4.6 ±.4) 1.996.999 15 ± 1.3 ph 8. (4. ±.) 1.978.999 18 ±.9 (4.5 ±.1) 1.997.999 16 ±.4 ph 11. (4.1 ±.1) 1.981.999 17 ±.4 (4.9 ±.3) 1.998.999 14 ± 1..8 M Na SO 4 (4. ±.1) 1.997.999 17 ±. (4.9 ±.1) 1.998.999 14 ±.3.1 M Na SO 4 (4. ±.1) 1.998.999 17 ±. (4.9 ±.1) 1.998.999 14 ±.1 1 mm HOCH(CH 3 ) (4.1 ±.) 1.998.999 17 ±.7 (4.9 ±.) 1.998.999 14 ±.6 5 mm NaN 3 (1. ±.1) 1.997.999 58 ± 3.7 (1.4 ±.1) 1.998.999 5 ±.3.5 M NaCl + 5 mm NaN 3 (1. ±.1) 1.998.999 58 ±. (1.4 ±.1) 1.998.999 5 ± 1 Freshwater (.4 ±.) 1.991.999 9 ±.3 (. ±.4) 1.995.999 3 ± 7.4 Seawater (7.1 ±.7) 1.99.997 9.9 ± 1. (6.7 ±.7) 1.996.998 16 ± 1.1 S4
.1 M NaCl (4.9 ±.1) 1.995.999 14 ±.3 (5.3 ±.1) 1.999 13 ±.3.5 M NaCl (5.3 ±.1) 1.996.998 13 ±.3 (6.6 ±.) 1.999 1 ±.3.5 M NaCl (6.7 ±.) 1.998.999 1 ±.3 (7.7 ±.5) 1.996.997 9.1 ±.6 1 M NaCl (7.7 ±.) 1.996.998 9. ±. (8. ±.) 1.998.999 8.7 ±. mg C/L HA (3.8 ±.1) 1.991.998 18 ±.3 (3. ±.1) 1.999 3 ±.4 4 mg C/L HA (3.1 ±.1) 1.996.998 ±.9 (. ±.1) 1.998.999 31 ± 1.7 8 mg C/L HA (1.8 ±.1) 1.991.99 38 ±. (1.5 ±.1) 1.999 46 ± 4.3 15 mg C/L HA (1.3 ±.1) 1.98.986 5 ± 4. (1.1 ±.5) 1.995.999 65 ± 3. 43 mg C/L HA (6.8 ±.3) 1 3.96.965 1 ± 4. (5.3 ±.3) 1 3.996.997 131 ± 7. 4 mg C/L L-HA (.9 ±.1) 1.98.987 4 ±.7 (3.4 ±.1) 1.99.995 ±.5 5 mg/l NaNO 3 (3.8 ±.1) 1.996.998 18 ±. (4. ±.3) 1.998.999 16 ± 1 1 mg/l NaNO 3 (3.6 ±.1) 1.996.997 19 ±.1 (3.9 ±.) 1.997.999 18 ± 1 1 mg/l NaNO 3 (.9 ±.1) 1.99.996 4 ±. (3. ±.1) 1.996 3 ±. 1 mg/l NaHCO 3 (3.9 ±.1) 1.997.999 18 ±. (4.5 ±.5) 1.999 15 ± 1 5 mg/l NaHCO 3 (3.9 ±.1) 1.998.999 18 ±.1 (4.4 ±.4) 1.999 16 ± 1 1 mg/l NaHCO 3 (3.8 ±.1) 1.999 18 ±.1 (4.3 ±.4) 1.999 16 ± 1.5 M MgCl (4.4 ±.1) 1.997.999 16 ±.4 (5.6 ±.5) 1.997.999 1 ± 1.64 M MgCl (4.6 ±.3) 1.995.999 15 ±.4 (6. ±.4) 1.997.999 11 ±.7.5 M MgCl (5.4 ±.) 1.993.999 13 ±.4 (8.3 ±.6) 1.987.998 8 ±.6.1 M NaBr (4. ±.1) 1.999 16 ±. (5.1 ±.3) 1.999 14 ±.6.5 M NaBr (4.8 ±.3) 1.996.999 14 ±.8 (6.1 ±.4) 1.997.999 11 ±.8 S5
.1 mm NaI (1. ±.1) 1.995.996 57 ± 5 (1.1 ±.1) 1.996.997 6 ±.8.5 mm NaI (9. ±.7) 1 3.984.997 78 ± 7 (9.5 ±. 3) 1 3.994.995 73 ± 5 1 μm Fe(III) (3.9 ±.1) 1.998 18 ±.4 (4.7 ±.1) 1.999 15 ±. 5 μm Fe(III) (3.5 ±.1) 1.998.999 ±.5 (4.3 ±.1) 1.999 16 ±.1 Solar irradiation (λ > 9 nm) Pure water a Freshwater (6. ±.6) 1 5.978.95 (1.1 ±.1) 1 4 (1. ±.) 1 4.96.94 (5.9 ± 1) 1 3 Seawater Simulated sunlight irradiation (λ > 9 nm) Pure water Freshwater (3.5 ±.) 1 5.998.999 (. ±.1) 1 4 (4.4 ±.1) 1 5.983.995 (1.6 ±.1) 1 4 Seawater 4 mg C/L HA (.3 ±.1) 1 5.984.991 (3. ±.1) 1 4 (.6 ±.3) 1 5.986.991 (.7 ±.3) 1 4 15 mg C/L HA (.8 ±.1) 1 5.98.996 (.5 ±.1) 1 4 (3.5 ±.) 1 5.976.995 (. ±.1) 1 4.5 M NaCl 4 mg C/L L-HA (8. ± 1.4) 1 5.958.991 (8.6 ± 1.6) 1 3 (6.8 ±.3) 1 5.97.973 (1. ±.1) 1 4 a No obvious degradation occurred, less than % within 84 hours for solar irradiation or 15 hours for simulated sunlight irradiation. S6
Table S3. Mean photodegradation rate constants (k, min 1 ) for phenicols under UV vis irradiation (λ > nm) with addition of Cl - and/or NaN 3 Reactions k Thiamphenicol Florfenicol Photolysis in pure water Photolysis for sole addition of 5 mm NaN 3 in pure water 1 O -induced photolysis in pure water Photolysis in.5 M Cl - aqueous solution Photolysis for joint addition of.5 M Cl - + 5 mm NaN 3 1 O -induced photolysis in.5 M Cl - solution k PW.4.49 k PW + NaN 3.1.14 k 1 O (PW).8.35 k - PW + Cl.67.77 k - PW + Cl + NaN 3.1.14 k1 O (PW + Cl ).55.63 S7
Table S4. Retention time (t R ) and molecular weight (Mw) of selected photodegradation products for thiamphenicol and florfenicol, and their pseudomolecular peak ions detected in ESI (+) and ESI (-) MS, and fragment ions detected in MS and MS 3. (Mw is calculated with chlorine isotope 35 Cl. The precursors ions used in MS and MS 3 are highlighted in bold. n.d: not determined.) No. t R (min) Thiamphenicol 9.84 355 I 1.15 77 II 5.53 31 III 6.63 31 IV 7.17 31 V 7.4 31 VI 8.4 31 Mw ESI (+) MS ESI (+) MS ESI (+) MS 3 ESI (-) MS ESI (-) MS ESI (-) MS 3 394 [M+K + ] +, 378 [M+Na + ] + 378 > 36, 34 n.d 354 [M-H + ] - 354 > 9 9 > 54 316 [M+K + ] +, 3 [M+Na + ] +, 34 [M+K + ] +, 358 [M+K + +H O] + 358 > 34 3 [M+H + ] +, 34 [M+K + ] +, 34 [M+Na + ] +, 34 [M+K + ] +, 34 [M+Na + ] +, 3 [M+H + ] +, 34 [M+K + ] +, 34 [M+Na + ] +, 36 [M+K + ] +, 344 [M+Na + ] +, 3 > 31, 163 n.d 76 [M-H + ] - 76 > 1, 34 > 3, 177 19 3 [M-H + ] - 3 > 7, 9, 145, 116 34 > 31, 8 n.d 3 [M-H + ] - 9, 7, 5, 3 > 7, 145 3 > 7, 34 > 33, 8 n.d 3 [M-H + ] - 9, 145, 116 3 > 7, 34 > 3, 8 n.d 3 [M-H + ] - 9, 145, 116 3 > 84, 36 > 3, 161 n.d 3 [M-H + ] - 7,9, 145 n.d 7 > 9, 145, 79 7 > 9, 145, 79 7 > 9, 145, 79 7 > 9, 145, 79 7 > 9, 145 S8
VII 3.43 153 VIII 14.56 311 Florfenicol.4 357 I 4.61 79 II 1.13 33 III 14.93 33 3 [M+H + ] + 19 [M+K + ] +, 176 > 116, 83 83 > 65 15 [M-H + ] - n.d n.d 176 [M+Na + ] + 35 [M+K + ] +, 334 [M+Na + ] + n.d n.d 31 [M-H + ] - 31>46 n.d 375 [M+NH 4 + ] +, 396 [M+K + ] +, 376 [M+H O+H + ] +, 38 [M+Na + ] +, 358 [M+H + ] + 375 > 34, 358; 396 > 378, 379 3 [M+Na + ] +, 3 > 8; 6 [M-H O+H + ] + 6 > 4 339 [M+H O+NH + 4 ] +, 36 [M+H O+K + ] +, 34 [M+H + ] + 34 [M+H + ] +, 34 [M+K + ] +, 36 [M+Na + ] +, 86 [M+ H + -H O] +, 339 > 3, 34, 86; 36 > 34 86 > 66, 187 34 > 3, 41, 6 4 > 6, 163, 131, 115 34 > 86; 34 > 3 187 > 159, 131 356 [M-H + ] - 356 > 336 78 [M-H + ] -, 6 [M-H O-H + ] -, 314 [M+Cl - ] - 78 > 58, 3 > 8, 3 [M-H + ] - 64, 38,, 118, 98 3 [M-H + ] -, 338 [M+Cl - ] -, 4 4 > 186, 118, 98 336 > 19, 185, 119 58 > 3, 186 64 > 36, 18, 8 186 > 158 S9
66 [M+ H + -H O-HF] + Supporting Information IV 1.93 189 1 [M+Na + ] + n.d n.d V 6.6 155 156 [M+H + ] +, 194 [M+K + ] +, n.d n.d 178 [M+Na + ] + 188 [M-H + ] -, n.d n.d 4 [M+Cl - ] - 154 [M-H + ] -, n.d n.d 19 [M+Cl - ] - 31 > 94, VI 7.4 313 96 [M-H O+H + ] + n.d n.d 31 [M-H + ] - 9 n.d S1
ln(c/c ) -1 - -3-4 -5 UV vis irradiation + Thiamphenicol 4 mg C/L L-HA 43 mg C/L HA 15 mg C/L HA 8 mg C/L HA 4 mg C/L HA mg C/L HA Pure water.1 M NaCl.5 M NaCl.5 M NaCl 1. M NaCl 4 6 8 1 1 14 Time (min) ln(c/c ) -1 - -3-4 -5-6 UV vis irradiation + Florfenicol 4 mg C/L L-HA 43 mg C/L HA 15 mg C/L HA 8 mg C/L HA 4 mg C/L HA mg C/L HA Pure water.1 M NaCl.5 M NaCl.5 M NaCl 1. M NaCl 4 6 8 1 1 14 Time (min) ln(c/c ) -. -.4 Simulated sunlight + Thiamphenicol 4 mg C/L L-HA 15 mg C/L HA 4 mg C/L HA Pure water.5 M NaCl ln(c/c ) -.1 -.3 Simulated sunlight + Florfenicol 4 mg C/L L-HA 15 mg C/L HA 4 mg C/L HA Pure water.5 M NaCl -.6 -.5 -.8 3 6 9 1 15 18 1 4 Time (h) -.7 3 6 9 1 15 18 1 4 Time (h) Figure S1. Effects of Cl -, Sigma humic acid (HA) and local humic acid (L-HA) on photodegradation kinetics of thiamphenicol and florfenicol under irradiation of UV vis (λ > nm) and simulated sunlight (λ > 9 nm). S11
Abs 4 3 15 mg C/L HA from Sigma Aldrich 4 mg CL HA from Sigma Aldrich 4 mg C/L L-HA from freshwater of Dalian, China 1 3 4 5 6 7 λ (nm) Figure S. UV vis spectra in water for humic acid (HA, Fluka No. 5368, Sigma Aldrich) and extracted local humic acid (L-HA) from the freshwater of a reservoir in Dalian, China. The freshwater was used in our study. S1
(a) Florfenicol in pure water upon irradiation (λ > nm) (b) Thiamphenicol in pure water upon irradiation (λ > nm) (c) Florfenicol and TEMP in pure water under dark (d) Thiamphenicol and TEMP in pure water under dark (e) Florfenicol and TEMP in pure water upon irradiation (λ > nm) (f) Thiamphenicol and TEMP in pure water upon irradiation (λ > nm) (g) Florfenicol, NaN 3 and TEMP in pure water upon irradiation (λ > nm) (h) Thiamphenicol, NaN 3 and TEMP in pure water upon irradiation (λ > nm) (i) Florfenicol, NaCl and TEMP in pure water upon irradiation (λ > nm) (j) Thiamphenicol, NaCl and TEMP in pure water upon irradiation (λ > nm) S13
(k) Florfenicol and DMPO in pure water upon irradiation (λ > nm) (l) Thiamphenicol and DMPO in pure water upon irradiation (λ > nm) (m) Fresh water containing TEMP under dark (n) Fresh water containing TEMP upon irradiation (λ > 9 nm) (o) Fresh water containing NaN 3 and TEMP upon irradiation (λ > 9 nm) (p) Fresh water containing DMPO upon irradiation (λ > 9 nm) (q) HA and TEMP in pure water under dark (r) HA and TEMP in pure water upon irradiation (λ > 9 nm) S14
(s) HA, NaN 3 and TEMP in pure water upon irradiation (λ > 9 nm) (t) L-HA and TEMP in pure water upon irradiation (λ > 9 nm) (u) HA and DMPO in pure water upon irradiation (λ > 9 nm) (v) L-HA and DMPO in pure water upon irradiation (λ > 9 nm) 33 33 334 336 338 34 Magnetic Field (G) 33 33 334 336 338 34 Magnetic Field (G) Figure S3. EPR Spectra for the samples a v. when needed, the initial concentrations were 1 mg/l for thiamphenicol and florfenicol, 15 mg C/L for HA, 4 mg C/L for L-HA,.5 M for NaCl, 5 mm for TEMP and DMPO, and 5 mm for NaN 3, respectively. Irradiation time was 5 min. S15
mau 15 15 1 75 5 5-5 Thiamphenicol Thiamphenicol in pure water under UV vis irradiation VII II III IV V VI I VIII.5 5 7.5 1 1.5 15 17.5 min mau 8 6 4 II III IV V Thiamphenicol Thiamphenicol in fresh water under simulated sunlight.5 5 7.5 1 1.5 15 17.5 min mau 8 6 4 II IV V III Thiamphenicol Thiamphenicol in HA solution under simulated sunlight.5 5 7.5 1 1.5 15 17.5 min S16
mau 15 15 1 75 5 5-5 Florfenicol in pure water under UV vis irradiation Florfenicol II III I VI V IV 5 1 15 5 min mau 8 6 4 II III Florfenicol Florfenicol in fresh water under simulated sunlight 5 1 15 5 min mau 8 6 4 II III Florfenicol Florfenicol in HA solution under simulated sunlight 5 1 15 5 min Figure S4. HPLC chromatograms of the phenicols and their photoproducts under irradiation of UV vis (λ > nm) and simulated sunlight (λ > 9 nm). The initial concentrations (C ) of the phenicols were 4 mg/l for UV vis irradiation and 1 mg/l for simulated solar irradiation, respectively. C of HA was 15 mg C/L. S17
x1 7 Thiamphenicol TP-1.D: TIC +All MS 3 ESI (+) MS Thiamphenicol 1 VII II III IV V VI I x1 7. Thiamphenicol ESI (-) MS Thiamphenicol TP-1.D: TIC -All MS 1.5 1..5. I VIII II III IV V VI VII 4 6 8 1 1 14 16 18 Time [min] S18
x1 7 5 Florfenicol ESI (+) MS Florfenicol FF-1.D: TIC +All MS 4 3 1 x1 7.5 Florfenicol ESI (-) MS V IV II I III Florfenicol VI FF-1.D: TIC -All MS. 1.5 I 1. VI.5. II III V IV 5 1 15 5 Time [min] Figure S5. Total ion chromatogram (TIC) obtained in ESI (+) and ESI (-) MS for UV vis (λ > nm) photodegradation solutions of thiamphenicol and florfenicol in pure water. S19
Thiamphenicol x1 6 4 Thiamphenicol 394. +MS, 1.min #783 ESI (+) MS 3 1 378. 8.9 1 3 4 5 6 7 8 9 m/z x1 4 Thiamphenicol 359.9 +MS(379.), 1.1min #785.8 ESI (+) MS (378).6 357.9.4 34.1.. 3 4 5 6 7 589.9 743.3 m/z S
x16 -MS, 1.min #787 Thiamphenicol 354.1 6 ESI (-) MS 4 5 3 35 4 45 m/z x1 6 Thiamphenicol 89.9 -MS(354.8), 1.min #788 1.5 ESI (-) MS (354) 1..75.5.5. 7. 4. 7.1 184.9 5 1 15 5 3 35 4 45 5 m/z S1
6 Thiamphenicol ESI (-) MS 3 (354 > 9) 53.9 -MS3(354.8->9.), 1.min #789 4 Product I x1 6. 5 1 15 5 3 35 4 45 5 m/z Product I ESI (+) MS +MS, 1.3min #963 316. 1.5 1..5. 3.3 6. 13.1 156. 176.9 31. 385.3 49.9 5 1 15 5 3 35 4 45 5 m/z S
Product I 16.9 +MS(31.), 1.4min #965 ESI (+) MS (3) 15 1 3.7 5 176.9 199.9 5 1 15 5 3 m/z x16 -MS, 1.3min #11 75.9 Product I 3 ESI (-) MS 1 15 15 175 5 5 75 3 35 35 m/z S3
x1 5. Product I 11.8 -MS(76.4), 1.4min #1 ESI (-) MS (76) 1.5 1. 191.9.5 Product II. x1 6 86.4 16. 5 1 15 5 3 35 4 m/z Product II 34. 59. +MS, 5.7min #48. ESI (+) MS 357.9 1.5 1..5. 1 3 4 5 6 7 8 9 m/z S4
x1 6 +MS(358.3), 5.7min #484 Product II 339.9 1.5 1. ESI (+) MS (358).75.5.5. 15 5 3 35 4 45 5 361.9 m/z 8 Product II ESI (+) MS 3 (358 > 34) 176.7 +MS3(358.3->34.1), 5.8min #486 6 4 31. 3. 5 1 15 5 3 35 4 m/z S5
x1 6 Product II 99.9 -MS, 5.7min #41 1.5 ESI (-) MS 1..5. 363.9 449.9 499.9 1 3 4 5 6 m/z 61. x1 5 Product II 6.9 -MS(3.1), 5.7min #413 3 ESI (-) MS (3) 1 98. 116. 145. 9. 51.8 69.9 5 1 15 5 3 35 4 m/z S6
x1 5 1. Product II 8.8 -MS3(3.1->7.), 5.7min #414 ESI (-) MS 3 (3 > 7).8.6.4 145.1 Product III.. x1 6. 79.4 18.9 117. 5 75 1 15 15 175 5 5 75 m/z Product III +MS, 6.8min #558 34. ESI (+) MS 1.5 1..5. 34.3 4.4 64.4 8.4 361.9 3.3 377.9 5 3 35 4 m/z S7
6 5 Product III ESI (+) MS (34) +MS(34.3), 6.8min #559 4 3 8. 3.9 16.9 1 9.9 59.8 71.9 36.1 5 1 15 5 3 m/z x1 5 4 Product III ESI (-) MS 3.1 -MS, 6.8min #57 3 1.3 346. 383.9 98. 17.1 415.8 467.5 519. 551.6 599. 87.1 1 3 4 5 6 7 8 m/z S8
x1 5 Product III 6.9 -MS(3.), 6.8min #58 1.5 ESI (-) MS (3) 1..75.5.5 98.3 116. 145. 9.1 69.8 51.9. 5 1 15 5 3 35 4 m/z x1 4 5 Product III ESI (-) MS 3 (3 > 7) 8.9 -MS3(3.->7.), 6.8min #59 4 3 145. 1 18.9 79.3 117.1 5 1 15 5 3 m/z S9
Product IV x1 6 1.5 Product IV 34. +MS, 7.4min #597 1.5 ESI (+) MS 1..75.5 34.1.5. 414.9 157. 7. 361.9 4.3 5 1 15 5 3 35 4 45 5 55 m/z 5 4 Product IV ESI (+) MS (34) +MS(34.3), 7.4min #598 3 79.8 3.9 1 113. 176.8 58.8 97.8 5 1 15 5 3 m/z S3
x1 5 6 Product IV 3. -MS, 7.4min #556 5 ESI (-) MS 4 3 1 5.1 336.9 375.1 41.9 479.4 561.5 641.3 1 3 4 5 6 7 8 m/z x1 5 1.5 Product IV 6.8 -MS(3.3), 7.4min #557 1.5 ESI (-) MS (3) 1..75.5.5. 98.3 116. 145.1 9.1 51.9 69.8 5 1 15 5 3 35 4 45 m/z S31
x1 4 4 Product IV ESI (-) MS (3 > 7) 8.8 -MS3(3.3->6.9), 7.4min #558 3 145. 1 79.3 18.9 194.1 Product V x1 6 1. 5 1 15 5 3 m/z Product V ESI (+) MS 34. +MS, 7.6min #68.8.6.4.. 34. 34.1 84.1 156.1 5 1 15 5 3 35 4 45 5 55 m/z S3
4 Product V ESI (+) MS (34) +MS(34.), 7.6min #69 3 79.9 3.1 1 68.5 93.9 176.8 41. 58.1 35.9 14 16 18 4 6 8 3 3 m/z x1 5 6 Product V 3. -MS, 7.6min #574 5 ESI (-) MS 4 3 1 6.1 199. 335.8 381.8 41.9 474.1 51.1 58.9 611.9639. 68.3 1 3 4 5 6 m/z S33
x1 5 Product V 6.8 -MS(3.3), 7.6min #575 1.5 ESI (-) MS (3) 1..75.5.5 98. 116. 145. 9.1 51.8 69.9. 5 1 15 5 3 35 4 m/z x1 4 4 Product V ESI (-) MS 3 (3 > 7) 8.8 -MS3(3.3->7.), 7.6min #576 3 145.1 1 79.4 18.9 5 75 1 15 15 175 5 5 75 m/z S34
Product VI x1 6 Product VI 36. +MS, 8.min #661. ESI (+) MS 1.5 1..5. 176.9 4.1 7. 9. 3. 175 5 5 75 3 35 35 375 4 344.1 m/z 3 Product VI ESI (+) MS (36) 99.9 +MS(36.6), 8.3min #66 1 16.9 345.1 316.6 31.9 144.9 5 1 15 5 3 m/z S35
x15 -MS, 8.min #67 Product VI 3. 8 6 ESI (-) MS 4 366. 411. 514. 1 3 4 5 6 m/z x1 5 Product VI 6.9 -MS(3.8), 8.min #68 1. ESI (-) MS (3).8.6.4.. 83.8 18.1 145.1 9. 181. 5 1 15 5 3 35 4 m/z S36
x1 4 4 Product VI ESI (-) MS 3 (3 > 7) 8.8 -MS3(3.8->7.1), 8.3min #69 3 145.1 Product VII 1 x1 5 5 79.3 18.9 5 1 15 5 3 m/z Product VII 176.1 +MS, 3.6min #311 4 ESI (+) MS 83.4 19. 3 1 116. 136.1 99.3 156.1. 33.9 6.7 95. 17. 1.9 47. 6 8 1 1 14 16 18 4 m/z S37
x1 5 +MS(176.6), 3.6min #31 Product VII 83.4 1.5 ESI (+) MS (176) 116.1 1..5. 6 8 1 1 14 16 m/z 5 Product VII ESI (+) MS 3 (176 > 83) 64.7 +MS3(176.6->83.4), 3.6min #313 4 3 1 5 55 6 65 7 75 8 85 9 95 m/z S38
x1 4 Product VII -MS, 3.5min #51 1.5 ESI (-) MS 9.3 1. 89.3 15..5. 188. 113.1 13.1 165. 66.7 74.5 99. 138. 171.1 179.1 86.4 11.1 6 8 1 1 14 16 18 m/z Product VIII x1 5. Product VIII ESI (+) MS 317. 35. 385.1 +MS, 14.7min #1191 1.5 1. 13.1 74.9 335.3.5 8.9 156. 7. 31. 369.3 399.1 41. 478.6. 5 1 15 5 3 35 4 45 m/z S39
x1 6 Product VIII 31.1 -MS, 14.7min #1163 1. ESI (-) MS.8 31.8.6.4.. 33.1 35.6 15 175 5 5 75 3 35 35 m/z x1 5 Product VIII 46. -MS(31.), 14.7min #1164. ESI (-) MS (31) 1.5 1..5 6.4. 134. 196.3 5 1 15 5 3 35 m/z S4
Florfenicol Intens. x1 6 8 Florfenicol 375.3 +MS,.6min #1813 ESI (+) MS 6 4 395.9 34.5 1 3 4 5 6 7 8 9 m/z Intens. x1 7 1.5 Florfenicol ESI (+) MS (375) 34.1 +MS(376.1),.6min #1814 1..75 357.9.5.5. 43.1 375.9 5 3 35 4 m/z S41
Intens. x1 4 5 Florfenicol ESI (+) MS (396) +MS(396.8),.6min #1815 379. 4 3 377.9 1 67.8 96.9 33.1 336.8 359. 8 3 3 34 36 38 m/z Intens. x1 5 Florfenicol 4.9 +MS3(376.1->34.6),.6min #1816 4 ESI (+) MS 3 (375 > 34) 3 1 6. 319.9 5 1 15 5 3 35 4 m/z S4
Intens. x1 7 Florfenicol 356. -MS,.6min #164.8 ESI (-) MS.6.4.. 336.9 393.9 47. 1 3 4 5 6 m/z Intens. x1 6 4 Florfenicol 336. -MS(356.9),.6min #165 ESI (-) MS (356) 3 1 19. 4 6 8 3 3 34 36 38 m/z S43
Intens. x1 4 1.5 1.5 Florfenicol ESI (-) MS 3 (356 > 336) 151.8 184.9 18.8 -MS3(356.9->336.5),.6min #167 1..75 119..5.5. 5 1 15 5 3 m/z 5.9 Product I Intens. x1 6 Product I 6.1 +MS, 4.8min #7 3 ESI (+) MS 1 31.9 4.3 356.3 135. 399.1 5 1 15 5 3 35 4 45 5 m/z S44
Intens. x1 6 Product I 41.9 +MS(6.8), 4.8min #8 1.5 ESI (+) MS (6) 1..5. 115.3 163.1 131. 5 1 15 5 3 m/z Intens. x1 5 Product I 81.9 +MS(3.7), 4.8min #9. ESI (+) MS (3) 1.5 1..5. 5 1 15 5 3 35 4 45 5 55 m/z S45
Intens. x1 5 Product I 115. +MS3(6.8->4.1), 4.9min #1.8 ESI (+) MS 3 (6 > 4).6 163..4 131... 145.1 5.9 188.9 5 75 1 15 15 175 5 5 75 m/z Intens. x1 6 Product I 78.3 -MS, 4.8min #197 ESI (-) MS 3 1 6.6 4 6 8 3 3 34 m/z 316. S46
Intens. x1 6 Product I 58. -MS(78.8), 4.8min #198 1.5 ESI (-) MS (78) 1..5. 5 1 15 5 3 35 4 45 5 m/z Intens. Product I 85.3.8 -MS3(78.8->58.5), 4.9min #193 8 ESI (-) MS 3 (78 > 58) 6 185.8 4-1 1 3 4 5 6 7 m/z S47
Product II x1 6 Product II 339.1 +MS, 1.3min #119 3 ESI (+) MS 36. 86. 34. 1 3.1 4.1 1 3 4 5 6 m/z x1 6 +MS(339.4), 1.3min #111 Product II 34.1 1.5 1. ESI (+) MS (339).75 31.9.5 86.3.5. 5 1 15 5 3 35 4 45 5 m/z S48
x1 6 Product II 341.9 +MS(36.3), 1.3min #1111.8 ESI (+) MS (36).6.4.. 1 3 4 5 6 7 m/z x1 5 6 Product II 85.9 +MS3(339.4->34.4), 1.4min #111 5 ESI (+) MS 3 (339 > 34) 4 3 1 187. 5 1 15 5 3 35 4 45 5 55 m/z 37.6 S49
4 Product II 341. +MS3(36.3->34.1), 1.4min #1113 ESI (+) MS 3 (36 > 34) 3 31.7 1 139.9 1 3 4 5 6 m/z x1 5 8 Product II 3. -MS, 1.3min #877 ESI (-) MS 6 4 118.1 79.3 98.3. 8.4 366. 45. 383. 457.8 51. 1 3 4 5 6 m/z 64.9 S5
x1 4 8 Product II ESI (-) MS (3) 118.1. 63.9 -MS(3.), 1.4min #878 6 4 98. 81.8 145. 183. 5 1 15 5 3 m/z 37.9 x1 4 Product II 35.9 -MS3(3.->64.), 1.4min #879 1.5 ESI (-) MS 3 (3 > 64) 1..75.5.5. 7.9 17.9 79.3 193.1 5 1 15 5 3 35 m/z S51
Product III x1 6 Product III 86.1 +MS, 15.min #134 1.5 ESI (+) MS 6.3 1. 34.1.5 66.4 341.9. 8.5 36. 118.4 135.5 188.4 44.4 385. 46. 5 1 15 5 3 35 4 m/z x1 6 1. Product III ESI (+) MS (86) 186.9 +MS(86.3), 15.1min #1341.8.6.4.. 3. 131. 5 75 1 15 15 175 5 5 75 3 m/z S5
x1 5 1.5 Product III ESI (+) MS 3 (86 > 187) 131.1 +MS3(86.3->187.), 15.1min #1343 1..5 159. 116.1. 6 8 1 1 14 16 18 m/z x1 5 Product III 4. -MS, 15.1min #119 4 3 ESI (-) MS 3. 1 118. 98.3.5 79.4 8.1 368. 338. 4. 64.1 389.9 45.9 449. 5 1 15 5 3 35 4 45 m/z S53
x1 4 Product III 185.9 -MS(4.), 15.1min #113 4 ESI (-) MS (4) 118.1 3.9 3 98. 1 71.5 16. 176.1 6 8 1 1 14 16 18 4 m/z x1 4 Product III 157.9 -MS3(4.->186.), 15.min #1131 1.5 ESI (-) MS (4 > 186) 1..5 18.. 143.1 6 8 1 1 14 16 18 4 m/z S54
Product IV x1 4 4 Product IV ESI (+) MS 15.3 161.1 +MS, 11.3min #11 3 14.1 1. 19.1 197.1 1 176. 191.1 6.8 1.3 17.5 1. 7.8 57.9 79.5 91.3 6 8 1 1 14 16 18 m/z x1 5 1. Product IV 188. -MS, 11.1min #78.8 ESI (-) MS.6.4.. 16. 15.1 18.1 18.1 3.9 4.9 53.9 84. 98.3. 3. 5 75 1 15 15 175 5 5 75 3 m/z S55
Product V x1 5 3 Product V ESI (+) MS 119. 135. +MS, 6.5min #571 1 15.1 178.1 6.8 194.1 85.4 15.4 17.1 163. 6 8 1 1 14 16 18 m/z x1 5 1.5 Product V ESI (-) MS 154. -MS, 6.4min #445 1..5. 79.4 3. 9.3 3.9 199.9 67.9 59.7 11.1 4.7 44. 336. 355.9 415.9 5 1 15 5 3 35 4 m/z S56
Product VI x1 5 Product VI +MS, 7.min #381 4 ESI (+) MS 98.1 3 96.1 78.1 83.4 1 4.4 63.1 81. 67.3 7.175.3 35.3 39.4 39. 47.1 51. 55.3 88.8 93.1 4 5 6 7 8 9 3 m/z x1 6 1.5 Product VI ESI (-) MS 314.4 -MS, 7.min #6 1. 31.1 313.1.5. 93. 367.4 338.1 348.6 18 4 6 8 3 3 34 36 m/z S57
x1 6 1. Product VI 93.7 -MS(314.6), 7.min #6.8 ESI (-) MS (31).6 9..4.. 5 1 15 5 3 35 4 45 5 m/z Figure S6. Mass spectra obtained in ESI (+) and ESI (-) MS n for UV vis (λ > nm) photodegradation solutions of thiamphenicol and florfenicol in pure water. Literature Cited (1) Bader, H.; Sturzenegger, V.; Hoigne, J. Photometric method for the determination of low concentrations of hydrogen peroxide by the peroxidase catalyzed oxidation of N,N-diethyl-p-phenylenediamine (DPD). Water Res. 1988, (9), 119 1115. S58