Supporting Information. Mass Balance of Perfluorinated Alkyl Acids in a Pristine Boreal Catchment

Transcription

1 Supporting Information Mass Balance of Perfluorinated Alkyl Acids in a Pristine Boreal Catchment Marko Filipovic 1, Hjalmar Laudon 2, Michael S. McLachlan 1, Urs Berger 1,3, * 1 Stockholm University, Department of Environmental Science and Analytical Chemistry (ACES), SE Stockholm, Sweden 2 Swedish University of Agricultural Sciences (SLU), Department of Forest Ecology and Management, SE Umeå, Sweden 3 Helmholtz Centre for Environmental Research UFZ, Department Analytical Chemistry, Permoserstr. 15, DE Leipzig, Germany * Corresponding author phone, ; , urs.berger@ufz.de Contains 16 tables, 5 figures, 20 pages S1

2 Table of contents Instrumental analysis and quantification... 3 Table S1. LC/MS/MS parameters for all analytes, internal standards and volumetric standards Analytical quality control... 4 Table S2. Compound-specific method detection limits (MDLs) for the different sample batches Table S3. Mean recoveries [%] of internal standards in the samples Table S4. Detection frequency [%] of PFAAs in the rain samples, snowmelt, and streams Table S5. Mean deviations [%] between results for analysis of field duplicates of all rain samples.. 6 Sampling... 7 Figure S1. Sampling occasions for rain, snow melt, stream 2, and stream 16 over the study period. 7 Precipitation and stream water flows at Krycklan Catchment Study... 7 Figure S2. Precipitation measured between May and November 2011 at the meteorological station at KCS (blue bars) and calculated from the rain samples in the present study (black dots)... 7 Figure S3. Water flow in stream 2 between June 2011 and July Figure S4. Water flow in stream 16 between June 2011 and July Calculation of PFAA inputs and outputs... 9 PFAA concentrations in rain Table S6. PFAA concentrations [pg L -1 ] in atmospheric deposition (rain), corresponding to analytical batch Table S7. PFAA concentrations [pg L -1 ] in atmospheric deposition (rain), corresponding to analytical batch Table S8. PFAA concentrations [pg L -1 ] in atmospheric deposition (rain), corresponding to analytical batch PFAA concentrations in snowmelt Table S9. PFAA concentrations [pg L -1 ] in snowmelt, corresponding to analytical batch Figure S5. PFAA concentrations [pg L -1 ] in sequential snowmelt samples during the whole snowmelt period. The last sample (M9) contained the majority of accumulated particles PFAA concentraions in streams Table S10. PFAA concentrations [pg L -1 ] in stream 2, corresponding to analytical batch Table S11. PFAA concentrations [pg L -1 ] in stream 16, corresponding to analytical batch Water mass balance for C2 and C Table S12. Input (rain and snow) and output (stream discharge) water volumes to and from C2 and C16 for different time periods Atmospheric inputs of PFAAs to the catchments Table S13. Atmospheric PFAA inputs [µg] to catchment C2. Ranges depict LBE-HBE Table S14. Atmospheric PFAA inputs [mg] to catchment C16. Ranges depict LBE-HBE Stream outputs of PFAAs from the catchments Table S15. Stream outputs of PFAAs [µg] in stream 2. Ranges depict LBE-HBE Table S16. Stream outputs of PFAAs [mg] in stream 16. Ranges depict LBE-HBE S2

3 Instrumental analysis and quantification Table S1. LC/MS/MS parameters for all analytes, internal standards and volumetric standards. Compound Abbreviation Precursor ion [m/z] Product ion [m/z] Cone [V] Perfluorohexanoic acid PFHxA Perfluoroheptanoic acid PFHpA Perfluorooctanoic acid PFOA Perfluorononanoic acid PFNA Perfluorodecanoic acid PFDA Perfluoroundecanoic acid PFUnDA Perfluorododecanoic acid PFDoDA Perfluorohexane sulfonate (linear) PFHxS Perfluorooctane sulfonate (branched) br-pfos Perfluorooctane sulfonate (linear) L-PFOS Perfluorodecane sulfonate PFDS Internal standards [ 13 C 2 ]-Perfluorohexanoic acid [ 13 C 4 ]-Perfluoroheptanoic acid [ 13 C 4 ]-Perfluorooctanoic acid [ 13 C5]-Perfluorononanoic acid [ 13 C 2 ]-Perfluorodecanoic acid [ 13 C 2 ]-Perfluoroundecanoic acid [ 13 C 2 ]-Perfluorododecanoic acid [ 18 O 2 ]-Perfluorohexane sulfonate [ 13 C 4 ]-Perfluorooctane sulfonate Recovery standards [ 13 C 8 ]-Perfluorooctanoic acid [ 13 C 8 ]-Perfluorooctane sulfonate a Collision energy CE a [V] 13 C 2 -PFHxA C 4 -PFHpA C 4 -PFOA C 5 -PFNA C 2 -PFDA C 2 -PFUnDA C 2 -PFDoDA O 2 -PFHxS C 4 -PFOS C 8 -PFOA C 8 -PFOS S3

4 Analytical quality control Procedural and instrumental blank contamination is a major challenge in most of the laboratories performing ultra-trace analysis of PFAAs. To trap and delay instrumental background contamination, a trapping column (Waters PFC kit ) was installed between the mobile phase mixing chamber and injector in the UPLC. Fluoropolymer tubing was exchanged to polyether ether ketone (PEEK). Procedural blank contamination was reduced by avoiding the use of fluoropolymer materials in the lab during sample preparation and by rigorously rinsing all equipment with methanol before use. A potential contamination from the bulk deposition collector was tested by analyzing the methanol rinses from all parts of the sampler, which did not show any detectable PFAAs. Field blanks experiments were not performed due to the non-availability of water that does not contain trace amounts of the target analytes. Procedural blanks (without water matrix) were extracted with each batch of samples. In total 18 and 24 procedural blanks were extracted with the atmospheric deposition and stream samples, respectively. Compoundspecific MDLs were determined on the basis of the analyte concentrations quantified in the procedural blank chromatograms. MLDs were defined as the arithmetic mean plus three times the standard deviation in the blanks and are given in Table S2. Blank correction was not performed. For PFAAs that did not display a signal in the procedural blank chromatograms, MDLs were set at a signal-to-noise ratio of three in the sample chromatograms. Absolute recoveries of all IS in all sample matrices are summarized in Table S3. The calibration curves bracketed all quantified concentrations in sample extracts and displayed r 2 values >0.99. The detection frequency of all analytes in the different matrices is shown in Table S4. Field duplicates were collected for all rain samples and the samples were analysed individually. The percentage deviations between analytical results for filed duplicates are summarized in Table S5. S4

5 Table S2. Compound-specific method detection limits (MDLs) for the different sample batches. MDLs atmospheric deposition MDLs streams Batch 1 Batch 2 Batch 3 Batch 4 Batch 5 Compound [pg L -1 ] [pg L -1 ] [pg L -1 ] [pg L -1 ] [pg L -1 ] PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos m/z L-PFOS m/z br-pfos m/z L-PFOS m/z PFDS S5

6 Table S3. Mean recoveries [%] of internal standards in the samples. n 13 C 2 - PFHxA 13 C 4 - PFHpA 13 C 4 - PFOA 13 C 5 - PFNA 13 C 2 - PFDA 13 C 2 - PFUnDA 13 C 2 - PFDoDA 18 O 2 - PFHxS Rain 22 79±27 62±62 78±21 92±28 111±44 152±95 88±51 63±35 74±30 Snowmelt 9 191±53 92±25 84±5 73±12 79±27 37±13 39±15 47±10 73±6 Stream ±13 59±9 58±8 117±21 105±27 217±79 226±123 36±6 73±16 Stream ±17 * 78±16 99±19 165±40 177±57 174±78 71±19 86±24 * 13 C 4 -PFHpA was not spiked to samples from stream C 4 - PFOS Table S4. Detection frequency [%] of PFAAs in the rain samples, snowmelt, and streams. n PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS PFDS Rain Snowmelt Stream Stream Table S5. Mean deviations [%] between results for analysis of field duplicates of all rain samples. n PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS Rain S6

7 Sampling Figure S1. Sampling occasions for rain, snow melt, stream 2, and stream 16 over the study period. Rain samplers and lysimeters continuously collected atmospheric deposition, covering the whole study period, wheras grab samples were taken from the streams. Precipitation and stream water flows at Krycklan Catchment Study /5-10/6 10/6-27/6 27/6-17/7 18/7-26/7 26/7-8/8 Precipitation (mm) 8/8-23/8 23/8-8/9 8/9-19/9 19/9-28/9 28/9-24/10 24/10-21/11. Figure S2. Precipitation measured between May and November 2011 at the meteorological station at KCS (blue bars) and calculated from the rain samples in the present study (black dots). S7

8 Figure S3. Water flow in stream 2 between June 2011 and July Figure S4. Water flow in stream 16 between June 2011 and July S8

9 Calculation of PFAA inputs and outputs Calculation of atmospheric input of PFAAs via rain and snow Total PFAA input from atmospheric deposition to C2 and C16 (N Deposition2/16, µg), respectively, was calculated for each PFAA and separately for the rain samples and the snowmelt samples according to equation 1. nn CC ii VV ii NN DDDDDDDDDDDDDDDDDDDD2/16 = ii=1 AA CC2/CC16 (1) AA SSSSSSSSSSSSSS where i is the sequential number of the rain (n=11) or snow (n=9) samples, respectively, C i is the PFAA concentration in sample i (µg L -1 ), V i is the volume of sample i (L), A Sampler is the surface area of the funnel (for rain) or lysimeter (for snowmelt) (m 2 ), and A C2/C16 is the area of the catchment C2 or C16, respectively (m 2 ). For rain samples, average values for C i and V i from the field duplicates were used. Calculation of stream output of PFAAs The water runoff Q Stream2/16,i (L) for a certain time period i represented by sample i from stream 2 and 16, respectively, was calculated according to equation 2. QQ SSSSSSSSSSSS2/16,ii = QQ SSSSSSSSSSSS 7,ii CCCC SSSSSSSSSSSS2/16 (2) Q Stream7,i is the total measured water runoff of stream 7 (L) for the time period i and CF Stream2/16 is the unitless correction factor for downscaling to stream 2 (CF Stream2 = 0.240) or upscaling to stream 16 (CF Stream16 = 144), respectively. Total PFAA output via stream runoff in stream 2 and stream 16 (N Stream2/16, µg), respectively, was calculated for each PFAA and separately for April-May 2012 (spring flood scenario) and June 2011-March 2012 (rest of the year) according to equation 3. nn NN SSSSSSSSSSSS2/16 = ii=1 CC ii QQ SSSSSSSSSSSS2/16,ii (3) where i is the sequential number of the samples from April-May 2012 (n=11) or June March 2012 (n=10 including the extrapolated values for December 2011-March 2012), C i is the measured (or extrapolated) PFAA concentration in sample i (µg L -1 ) and Q Stream2/16,i (see equation 2) is the water runoff represented by sample i (L) in stream 2 and 16, respectively. S9

10 PFAA concentrations in rain Table S6. PFAA concentrations [pg L -1 ] in atmospheric deposition (rain), corresponding to analytical batch 1. Sampling period 2011 Sample name PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS PFDS 5/5-10/6 1 1, <42 < <69 5/5-10/ <42 < <69 10/6-27/ , , <42 < <69 10/6-27/ , < <69 27/6-18/ , <42 < <69 27/6-18/ , < <69 18/7-26/ , <69 18/7-26/ , < <69 26/7-8/ <42 < <69 26/7-8/ , <69 S10

11 Table S7. PFAA concentrations [pg L -1 ] in atmospheric deposition (rain), corresponding to analytical batch 2. Sampling Sample PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS PFDS period 2011 name 8/8-23/ <3 23/8-08/ <3 08/09-19/ <3 19/09-28/ < <3 28/09-24/ < <3 24/10-21/ <3 Table S8. PFAA concentrations [pg L -1 ] in atmospheric deposition (rain), corresponding to analytical batch 3. Sampling period 2011 Sample name PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS 8/8-23/ < <3 23/8-08/ <3 08/09-19/ <3 19/09-28/ <3 28/09-24/ <3 24/10-21/ <3 PFDS S11

12 PFAA concentrations in snowmelt Table S9. PFAA concentrations [pg L -1 ] in snowmelt, corresponding to analytical batch 1. Sampling date 2012 Sample name PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS PFDS M <28 < < M <28 < < M <28 <42 < < M <28 <42 < < M <42 < < M <42 < < M <42 <18 <5 <3 < M <42 <18 <5 <3 < M < <69 S12

13 Water volumes of the different samples M1: 11.5 L M2: 25.1 L M3: 72.4 L M4: 42.5 L M5: 26.7 L M6: 26.9 L M7: 40.8 L M8: 34.2 L M9: 6.3 L Figure S5. PFAA concentrations [pg L -1 ] in sequential snowmelt samples during the whole snowmelt period. The last sample (M9) contained the majority of accumulated particles. S13

14 PFAA concentraions in streams Table S10. PFAA concentrations [pg L -1 ] in stream 2, corresponding to analytical batch 4. Sampling date Sample name PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS PFDS Rest of the year Spring flood /27 R2-2 < <17 < < /18 R < < R < < /28 R <17 < < /25 R2-6 <320 < <17 < < /28 R <18 20 < < R <17 < < R2-9 < <17 < < R2-10 < <31 < < R2-11 <320 < <17 < < R2-12 < <17 < < R2-13 < < < R <17 < < R2-15 <320 < <18 <17 < < R <17 < < R <31 <5 <20 <22 < R2-18 < <17 < < /27 R2-19 < < < /31 R <17 < <69 S14

15 Table S11. PFAA concentrations [pg L -1 ] in stream 16, corresponding to analytical batch 5. Rest of the year Spring flood Sampling date Sample name PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS PFDS /21 R16-2 <104 < <28 <44 < < R <28 <44 < < /31 R16-4 <104 < <28 <44 <36 6 <7 <7 < R16-5 <104 < <28 <44 < < /28 R16-6 <104 < <28 <44 < < /28 R16-7 <104 < <28 <44 < < R16-8 <104 < <28 <44 < < R16-9 <104 < <28 <44 <36 < < R16-10 <104 < <28 <44 <36 19 <7 <7 < R16-11 < <28 <44 < < R <44 < < R < <28 <44 < < R < <44 < < R < <44 < < R < <44 < < R < <28 <44 < < R < <44 < < /19 R16-19 <104 < <44 < < /31 R < <28 <44 < <69 S15

16 Water mass balance for C2 and C16 Water mass balances were assembled for the three time periods for both catchments. Rain and snowmelt water were considered as input and stream runoff as water output. Water input and output volumes as well as the mass balances for all scenarios are presented in Table S12. The total atmospheric deposition sampled in the present study was 609 mm (410 mm rain and 199 mm snowmelt), which is very close to the long term average of 614 mm (ref. 28 in the main text). The rain volumes collected in this study also compared well with the World Meteorological Organization standard measurements conducted at the Svartberget field station (Figure S1). For the spring flood period (input total snowmelt, output stream discharges April-May 2012) the mass balances were almost closed (output was 92% and 98% of input for C2 and C16, respectively, Table S12), suggesting that during this relatively short time period with high water fluxes very little volatilization occurs. On the other hand, only 39% (C2) and 42% (C16) of the total water input (all rain samples) was discharged in the streams between June 2011 and March This observation is in agreement with the expected volatilization of water from vegetation or the soil surface at the elevated summer temperatures. Summing up these two periods results in water mass balances of 57% and 60% for C2 and C16 over the whole year, which agrees well with the observed yearly average of 50% for the C7 reference catchment (ref. 28 in the main text). Table S12. Input (rain and snow) and output (stream discharge) water volumes to and from C2 and C16 for different time periods. The water mass balances are presented as percentage output relative to the input. Atmospheric input (10 6 m 3 ) Stream output (10 6 m 3 ) Mass balance C2 C16 C2 C16 C2 C16 Spring flood % 98% Rest of the year % 42% Whole year % 60% S16

17 Atmospheric inputs of PFAAs to the catchments Table S13. Atmospheric PFAA inputs [µg] to catchment C2. Ranges depict LBE-HBE. Sampling date PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS 5/5-10/ /6-27/ /6-18/ /7-07/ /7-8/ /8-23/ /8-08/ /09-19/ /09-28/ /09-24/ /10-21/ Sum Snowmelt Sum Rain Whole year S17

18 Table S14. Atmospheric PFAA inputs [mg] to catchment C16. Ranges depict LBE-HBE. Sampling date PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS 5/5-10/ /6-27/ /6-18/ /7-07/ /7-8/ /8-23/ /8-08/ /09-19/ /09-28/ /09-24/ /10-21/ Sum Snowmelt Sum Rain Whole year S18

19 Stream outputs of PFAAs from the catchments Table S15. Stream outputs of PFAAs [µg] in stream 2. Ranges depict LBE-HBE. Rest of the year Sampling date PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS / / / / / a a a / / Sum Spring flood Spring flood Sum Rest of the year Whole year a Calculated based on PFAA concentrations in sample S19

20 Table S16. Stream outputs of PFAAs [mg] in stream 16. Ranges depict LBE-HBE. Sampling date PFHxA PFHpA PFOA PFNA PFDA PFUnDA PFDoDA PFHxS br-pfos L-PFOS Rest of the year Spring flood / / / / a a a a / / Sum Spring flood Sum Rest of the year Whole year a Calculated based on PFAA concentrations in sample /28 S20