Page 27 - Application Notebook - PFAS Analysis

SSI-LCMS-102

■ Results and Discussion
Calibration Data The initial calibration curve was used to quantitate the
A series of 10 calibration levels ranging from 1.25 ppb to subsequent injections. Table 4 lists representative
100 ppb with an injection volume of 5 uL was used in this concentrations and percent recovery for all targets in EPA
study. These concentrations were used to reflect the 250- Method 537.1.
fold sample concentration required in EPA Method 537.1
(250 ml of sample are extracted and concentrated down to
1 mL for injection in the LC/MS/MS).

Table 2: LC System and Parameters Table 3: LCMS Acquisition Parameters
LC System Nexera-X2 UHPLC System MS Instrument LCMS-8045
Shim-pack™ Velox, Interface Electrospray Ionization (ESI)
Analytical
o
Column 2.1mm ID × 150mm, 2.7 μm, Interface Temp. 100 C
Part No. 227-32009-04 Desolvation Line
o
Shim-pack XR-ODS 100 C
Solvent Delay 50mm x 2mm x 2.2µm, Temp.
Column Heat Block o
Part No. 228-41605-93 Temp. 200 C
o
Column Temp. 40 C Heating Gas
Injection Volume 5 µL Flow 15 L/min
A: 20 mM Ammonium Acetate
Mobile Phase Drying Gas Flow 5 L/min
B: Methanol
Flow Rate 0.25 mL/min Nebulizing Gas 3 L/min
Run Time 35 minutes Flow
Total MRMs 48

Table 4: Calculated concentrations for the low, mid, and high level
standards for all targets in EPA Method 537.1

Low (80 ppt) Mid (200 ppt) High (400 ppt)
Retention 2
Compound R
Time
Concentration %Recovery Concentration %Recovery Concentration %Recovery
PFBS 7.883 0.99328 86.8 108 217 108 384 96
PFHxA 8.462 0.99632 84.0 105 210 105 379 94.7
HFPO-DA 8.704 0.99727 85.2 107 210 105 380 94.9
PFHpA 9.451 0.99459 88.8 111 212 106 368 92.1
PFHxS 9.487 0.99419 84.8 106 212 106 369 92.2
ADONA 9.593 0.99770 84.4 106 211 106 383 95.8
PFOA 10.885 0.99611 84.4 106 213 106 374 93.6
PFNA 12.678 0.99633 86.0 108 210 105 375 93.7
PFOS 12.681 0.99568 87.2 109 212 106 378 94.4
9Cl-PF3ONS 13.743 0.99833 83.6 105 210 105 386 96.5
PFDA 14.678 0.99718 85.2 107 212 106 381 95.3
N-MeFOSAA 15.610 0.99724 82.8 104 214 107 382 95.4
N-EtFOSAA 16.618 0.99557 85.6 107 212 106 376 93.9
PFUnA 16.677 0.99736 81.6 102 212 106 382 95.4
11Cl-PF3OUdS 17.635 0.99810 82.0 102 212 106 388 96.9
PFDoA 18.590 0.99653 83.6 105 214 107 376 94.1
PFTriA 20.309 0.99644 85.2 107 211 106 376 94.0
PFTreA 21.835 0.99753 85.2 107 210 105 382 95.4