A Fully Validated LC-MS/MS Method for Analysis of Trace Fluorotelomer Alcohols from Water

Transcription

1 A Fully Validated LC-MS/MS Method for Analysis of Trace Fluorotelomer Alcohols from Water Million Woudneh, Blair Surridge, Richard Grace, Dale Hoover Axys Analytical Services Ltd. Sidney, BC, V8L 3S8

2 Overview Introduction Instrumental analysis Sample extractions SPE extractions L-L extractions Solvent reduction/concentration and exchange Extract cleanup Sample Sample storage Sample pretreatment Method performance data Field sample data Conclusions 2

3 1. Introduction Flurotelomer alcohols are linear, polyfluorinated alcohols Structure CF3-(CF)n-CH2-CH2-OH, typically n = 3 to 15 Nomenclature X:Y X = # of fluorinated carbons (x = 4, 6,8 to 16) Y = # of hydrogenated carbons (Y = 2) E.g. 4:2, 6:2, 16:2 Environmental problem Directly released into the environment Potential precursors of other PFCs There is lack of analytical methods that are suitable for analysis of these compounds from water. 3

4 2. Instrumental analysis Analyte 4:2 to 8:2 1:2 to 16:2 [Parent]/[Daughter] MRM Transitions Primary = [M-3HF-H] - / [M-4HF-CO-H] - Confirmation = [M-H] - / [M-3HF-H] - Primary = [M-H] - / [M-3HF-H] - Confirmation =[M-3HF-H] - / [M-4HF-CO-H] - Quantification reference D4 4:2 13C2,D2 6:2 13C2,D2 8:2 13C2,D2 1:2 Surrogates D4 4:2 13C2,D2 6:2 13C2,D2 8:2 13C2,D2 1:2 Recovery standard 13C2-PFOUEA [M-H] - / [M-3HF-H] - [M-H] - / [M-3HF-H] - [M-H] - / [M-3HF-H] - [M-H] - / [M-3HF-H] - [M-H]-/ [M-13CO2-HF-H]- 13C2-PFOUEA 13C2-PFOUEA 13C2-PFOUEA 13C2-PFOUEA External standard Ref: Berger et al., 24. Eur. J. Mass Spectrum. 1,

5 2. Instrumental Analysis contd Compound 4:2 Conc. Range (ng/ml) r % rec FC7K_187S11 % FC7K_187S11 % 3.47* : :2 min min 6:2 8: FC7K_187S11 % :2 min 1:2 12: FC7K_187S11 % 1: min 14: FC7K_187S11 % 12: :2 Time.23 Solv. 35 Solv..989 Flow FC7K_187S11 % 14: min min (Min) A (%) B (%) (ml/min) FC7K_187S11 16: % min Solv. A = MeOH, Solv B = H2O at ph = Column = Waters Xterra, C18, 3.5µm, 2.1 mm x mm 5

6 3. Extraction SPE extraction Analyte recovery from different SPE cartridges :2 6:2 8:2 1:2 12:2 14:2 16:2 LiChrolut EN HLB MAX WAX 6

7 3.1 Extraction - L-L extraction Analyte recovery by L-L extraction using DCM and MTBE :2 6:2 8:2 1:2 12:2 14:2 16:2 DCM MTBE 7

8 3.2 Solvent reduction / concentration Analyte Solvent reduction by N2, % Rec DCM MTBE MeOH MeOH basic Rotary Evapo. MTBE 4: : : : : : : ml of solvent reduced using N2. 3 ml of MTBE was reduced using rotary evaporation test 8

9 4. Extract cleanup Compound % rec. NH2 SPE % rec. PAC % rec..2 um filter 4: : : : : : : NH2 SPE (5 mg) column was eluted with 7 ml of 3:1 MTBE:MeOH 15 mg PAC 9

10 5. Sample - container and storage conditions L, Open, room temp :2 6:2 8:2 1:2 12:2 14:2 16:2 4:2 6:2 8:2 1:2 12:2 14:2 16: L, Open, room temp..5 L, Closed, room temp. 95 4:2 4:2-5 6:2 8:2 1:2 12:2 14:2 16:2 4:2 6:2 8:2 1:2 12:2 1 L, Closed, room temp L, Closed, 4 o C 95 6:2 8:2 1:2 12:2 14:2 16: :2.5 L, Fresh Control 6:2 8:2 1:2 12:2 14:2 14:2 16:2 16:2 1

11 5. Sample - container contd. Analytes % rec. in sample % rec. in 4 ml of bottle rinse bottle extraction Total loss on poly propylene bottle (%) 4:2 17 ND ND 6: ND : : : : :

12 6. Sample pretreatment / filtration Analytes Spiked (ng) % Loss from reagent water (n=2) %Loss from river water (n=2) 4: : : : : : :

13 7. Method performance data Spiked samples Analyte Spiked SPE -Extraction L-L -Extraction (ng) Reagent water River water Reagent water River water (n=5,%rsd) (n=4,%rsd), (n=5, %RSD) (n=4, %RSD) 4: (15 ) 83.1 (14 ) 12 (9.1) 13 (7.1) 6: ( 8.3) 99.4 (1) 11 (8.) 97.9 (6.7) 8: (7.6) 97.9 (7.5) 13 (4.1) 94.7 (6.5) 1: (7.7) 18 (9.1) 15 (8.) 99.4 (6.2) 12: ( 31) 84.5 (7.2) 97.2 (9.4) 76.8 (7.5) 14: ( 26 ) 87. (2.4) 93.7 (14) 9.2 (6.4) 16: (33 ) 83.7 (5.2) 97.2 (2) 16 (9.2) Surrogates (ng) Surrogate standard recoveries 13C2,D2 4: C2,D2 6: C2,D2 8: C2,D2 1:

14 7.1 Method performance - MDL Analyte Spike (ng/l) Mean SD MDL 1 (ng/l) IDL (ng/l) Literature. 2 (ng/l) 4: : : : N/A 12: N/A 14: N/A 16: N/A Number of replicates = 9, Student s t-value =2.896, MDL = SD*t-value 1 Federal Register 4 CFR Part 136, Appendix B, October 26, 1984, no iteration. 2 Szostek et al. Rapid Commun. Mass Spectrom. 26; 2:

15 7. Field sample data - collected from suspected sites of contamination. Analyte Site Site Site Site Site Site Site #1 #2 #3 #4 #5 #6 #7 Concentration (ng/l) 4:2 <1.16 <3.51 <.78 <.98 <1.8 <11.1 <7.51 6:2 < <71.2 <43.1 <44.4 <313 <155 8:2 < <7.23 <9.57 <13.1 <91.4 <63. 1:2 <27.9 <194 <8.15 <11.6 <8. <164 <237 12:2 <9.46 <52.8 <4.45 <2.59 <3.42 <29.4 < :2 <5.87 <44.5 <3.9 <2.53 <2.34 <48.1 < :2 <5.86 <87. <3.52 <3.5 <2.1 <56.9 <

16 8. Conclusions An isotope dilution LC-MS/MS suitable for monitoring of s from environmental waters was developed and validated. Loosely capped containers could result in significant or complete loss of s. Significant losses of s were measured when samples were stored using polypropylene sample containers. Filtration of aqueous samples should be avoided to reduce analyte loss during filtration 16

17 Future work Application of the method to real field sample monitoring. Development of LC-MS/MS methods for other matrices e.g. air and tissue. Development of cleanup techniques that can be applied to more complex matrices 17

18 Acknowledgements To Axys analytical Lab Staff Wang Guanghui, and Jenny Pape. 18