Page 17 - Application Notebook - PFAS Analysis

Application No. C184
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Preparation of Samples final volume of 1 mL in 96:4% methanol:water after
adding IS. It is recommended to vortex the LC vials
Sample preparation and SPE were carried out prior to injection and analysis by LC-MS/MS to ensure
according to EPA Method 537. A vacuum manifold with that all solutions are homogenized and consistent
a high-volume sampling kit fitted with PEEK tubing was results are obtained.
used to reduce potential PFAS contamination.
Extractions were performed using Biotage-ISOLUTE® LCMS Analytical and Instrument Conditions
101 polystyrenedivinylbenzne (SDVB) cartridges
(500 mg / 6 mL, Part No. 101-0050-C). Each cartridge PFAS analyses were carried out by injecting 1 µL of
was first conditioned with methanol, followed by LCMS- the extracted aliquot into the Shimadzu LCMS-8045
grade water. The water sample was first fortified with and LCMS-8050 with the conditions shown in Table 2
surrogates and passed through the SPE cartridge. and Table 3. PFAS compounds, including branched
Compounds were eluted from the solid phase with and linear isomers of PFHxS and PFOS, were
8 mL of methanol and evaporated to dryness using separated using a Shim-pack™ Velox SP-C18 column.
nitrogen. Extracted samples were reconstituted to a

Table 2. LC System and Parameters Table 4. Retention times (RT) and MRM transitions
PFAS Compound RT (mins) Precursor Ion Product Ion
LC System : Nexera™-X2 UHPLC System
PFBS 8.046 298.90 80.10*
Shim-pack™ Velox SP-C18, 99.10
Analytical Column : 150mm x 2.1mm x 2.7µm, 4:2 FTS 8.558 327.00 80.90*
Part No. 227-32003-04 307.00
Shim-pack™ XR-ODS II, PFHxA 8.614 312.90 269.00*
Solvent Delay 119.10
Column : 75mm x 2mm x 2.2µm,
Part No. 228-41605-93 M2PFHxA (Surr.) 8.650 315.00 270.00*
79.90*
Column Temp. : 40 C PFPeS 8.666 348.90 98.90
o
319.00*
PFHpA 9.512 362.90
169.00
Injection Volume : 1 µL # 80.10*
PFHxS 9.558 398.90
99.10
406.90*
6:2 FTS
427.00
10.770
Mobile Phase : A: 20 mM Ammonium Acetate 80.00
B: Methanol 369.00*
PFOA 10.840 412.90
169.00
Flow Rate : 0.25 mL/min PFHpS 10.859 448.90 79.90*
98.90
M2PFOA (IS) 10.877 415.00 370.00*
Run Time : 35 minutes 418.90*
PFNA 12.545 462.90 219.00
# A much lower injection volume was used as compared to the injection 80.10*
volume of 10 µL in EPA Method 537. PFOS 12.550 498.90 99.10
M4PFOS (IS) 12.575 503.00 80.00*
Table 3. LCMS Acquisition Parameters
8:2 FTS 14.436 526.90 506.90*
MS Instrument : LCMS-8045 and LCMS-8050 80.90
PFNS 14.469 548.90 79.90*
98.90
Interface : Electrospray Ionization (ESI)
M2PFDA (Surr.) 14.484 515.00 469.95*
468.90*
Interface Temp. : 300 C PFDA 14.486 512.90 219.00
o
M-N-MeFOSAA (IS) 15.403 572.90 419.00*
Desolvation Line Temp. : 100 C 419.00*
o
N-MeFOSAA 15.423 569.90
482.90
o
Heat Block Temp. : 200 C M-N-EtFOSAA (Surr.) 16.357 588.90 419.00*
79.90*
PFDS 16.397 598.90
98.90
Heating Gas Flow : 15 L/min 419.00*
N-EtFOSAA 16.411 583.90
482.90
Drying Gas Flow : 5 L/min PFUnA 16.449 562.90 519.00*
269.00
568.90*
PFDoA 18.339 612.90
Nebulizing Gas Flow : 3 L/min 169.00
PFTriA 20.035 662.00 618.90*
169.00
Total MRMs : 48 PFTreA 21.549 712.90 668.90*
169.00
* Quantifying ions