UNDER
THE
ENVIROCLASS
fused-core.comHALO and Fused-Core are registered trademarks of Advanced Materials Technology, Inc.
1
Introducing HALO® PFAS Column Solutions INTRODUCTIONPer- and polyfluoroalkyl substances (PFAS) are human-made fluorinated compounds that contain carbon-fluorine bonds. With desirable properties such as resistance to heat, stains, and water, they were and some continue to be, used for consumer products such as food packaging, nonstick cookware, food processing equipment, cleaning products, fire-fighting foams, paints, and stain- and water-resistant fabrics and carpeting. These compounds do not break down easily due to the presence of the strong carbon-fluorine bonds, which has earned them the nickname “forever chemicals.” There are nearly 5000 PFAS compounds mainly because as some were banned others were created to replace them. Part of the problem with PFAS is that they are found everywhere and have entered water supplies. Another issue with PFAS is that only certain compounds have been extensively studied for their impact on human health. There is worldwide concern about the presence of PFAS in the environment. In the US, the Environmental Protection Agency (EPA) has developed methods for the analysis of drinking water (533 and 537.1) and another method for the analysis of groundwater, surface water, and wastewater samples (8327). The EPA has a health advisory limit of 70 ppt for levels of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) either combined or individually, but it is non-enforceable and non-regulatory. This leaves individual states to determine maximum levels for themselves. In Europe, the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation restricts PFOA and its precursors while PFOS is restricted by the EU persistent organic pollutants (POPs) Regulation. More comprehensive regulations are currently under development in the EU.
People are exposed to PFAS in several ways. One way is through eating PFAS contaminated food. The food can become contaminated through the soil and water used to grow it, the packaging that contains the food, or through PFAS contaminated equipment that processed the food. Another way people are exposed is through PFAS-containing products, such as nonstick cookware, carpets, clothes, and food packaging. Where water has become contaminated with PFAS, the drinking water can expose people to PFAS. These sites are normally near PFAS production plants or facilities that manufactured PFAS-containing products. Other typical locations are near oil refineries, airports, or military bases where aqueous film forming foam (AFFF) formulations were used to extinguish fires mainly during training exercises.
Since PFAS accumulate in the body, the increased level of these compounds over time may cause health effects. Exposure to PFOA and PFOS can cause increased cholesterol, low birth weights, immune system effects, cancer (PFOA), and thyroid hormone disruption (PFOS). While the health effects of PFOA and PFOS have been studied, the same is not true for all of the 1000’s of PFAS compounds. Consequently, research continues to uncover the impact that PFAS have on human health. It was recently reported that 6:2 fluorotelomer alcohol (6:2 FTOH) is more toxic than perfluorohexanoic acid (PFHxA), which had been used to assess the toxicity of 6:2 FTOH. This has prompted the manufacturers of food packaging that contain 6:2 FTOH to voluntarily phase out the sale of these products in the US over a three-year time span beginning in January 2021.
AMT-08-020
2fused-core.comHALO and Fused-Core are registered trademarks of Advanced Materials Technology, Inc.
HALO® PFAS and HALO® PFAS Delay columns have been developed specifically for the analysis of PFAS. The densely bonded, extensively endcapped ODS stationary phase of HALO® PFAS provides an application assured and method qualified solution for PFAS analysis. The highly retentive endcapped alkyl silane of the HALO® PFAS Delay column provides high retention of PFAS compounds across various mobile phase conditions and is used to delay background instrument PFAS contamination from coeluting with analyzed samples. Figure 1 shows the HALO® PFAS and HALO® PFAS Delay particle and ligand structures.
APPLICATIONSEvery HALO® PFAS lot is quality assurance tested by LC-MS/MS analysis of a mix of 17 PFAS consisting of a broad range of short and long chain compounds. Set specifications ensure reproducible results across multiple lots. An example LC-MS/MS MRM QA separation is shown in Figure 2.
Figure 2. Representative MRM QA chromatogram showing the analysis of 17 PFAS compounds using HALO® PFAS.
0.0 2.5 5.0 7.5 10.0 12.5 15.0 min
0
25000
50000
75000
100000
125000
150000
175000
200000
225000
250000
1 23
45
6
7
8,9 1011,12
1314
15
1617
PFAS DELAY PFAS ANALYTICAL
SiO
CH3
CH3
C18H37CH3SiO
CH3
CH3
(CH2)n
Delay Column: HALO® PFAS Delay, 2.7 µm, 3.0 x 50 mmAnalytical Column: HALO® PFAS, 2.7 µm, 2.1 x 100 mmMobile Phase: 10 mM Ammonium Acetate [A]; Methanol [B]Gradient: 33-98% B in 18 minFlow Rate: 0.4 mL/minInitial Back Pressure: 420 bar
Temperature: 35 °CDetection: Negative ESI, MRMInjection Volume: 1 µLSample: PFAC-MXB (Wellington Laboratories)Concentration: 100 ppb in 96% Methanol
1. PFBA2. PFPeA3. PFBS4. PFHxA5. PFHpA6. PFHxS7. PFOA8. PFNA9. PFOS10. PFDA11. PFDS12. PFUnDA13. PFDoDA14. PFTrDA15. PFTeDA16. PFHxDA17. PFOcDA
TEST CONDITIONS
PEAK IDENTITIES
Figure 1.
Time (min)
3fused-core.comHALO and Fused-Core are registered trademarks of Advanced Materials Technology, Inc.
Figure 3. PFOA found in a null injection run on a HALO® PFAS Delay column and a HALO® PFAS column. (Conditions same as Figure 2.)
For those just beginning to venture into PFAS analysis, the concept of a delay column may be unfamiliar. PFAS contamination is commonly found in the HPLC equipment used to conduct the experiments. This contamination stems from the solvent bottle caps, PTFE tubing, filters, sample preparation consumables, solvents, and even the laboratory environment itself. While fluorocarbon-free replacements exist, there may still be system contamination which is detrimental for trace analysis. The HALO® PFAS Delay column is meant to trap and delay any PFAS that is unrelated to the sample of interest. Figure 3 shows a null injection (gradient was run, but no sample was injected) and PFOA from the system is clearly visible. The prevalence of PFOA is commonly observed as an instrument materials contaminant.
0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 min
-1000
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
PFOAfrom LC system
When a sample is run, the PFOA from the LC instrument elutes at a later time compared to the PFOA from the sample. See Figure 4.
0.0 2.5 5.0 7.5 10.0 12.5 15.0min
0
25000
50000
75000
100000
125000
150000
175000
200000
225000
250000
MRM 413.0 > 369.0 for PFOA.
PFOA from LC System
PFOA from Sample
PFOAfrom LC system
Figure 4. PFOA from sample and LC system run on a HALO®
PFAS Delay column and a HALO® PFAS column.
Time, min.
Time (min)
4fused-core.comHALO and Fused-Core are registered trademarks of Advanced Materials Technology, Inc.
4x10
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
3.2
3.4
-ESI TIC MRM Frag=166.0V (** -> **) Well_05.d
Counts vs. Acquisition Time (min)1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
12
34,5 6
78
9
1011
12
13,14
15
16
1718 19
20
21
22
23
24,25
26
27
28 29
Figure 5. HALO® PFAS separation of branched and linear PFHxS isomers from a well water sample.
One of the challenging aspects to PFAS analysis is the presence of linear and branched isomers. Branched isomers are a byproduct of the process of electrochemical fluorination (ECF) used to manufacture PFAS. Conversely, when telomerization is used, only linear isomers are formed. Branched PFAS isomers, which are more polar, are less retained compared to the linear PFAS isomers. This explains why branched isomers are found in water while linear isomers are found in soil and sediment. In Figure 5, a well water sample is run on a HALO® PFAS column and shows the excellent resolution of the branched and linear isomers of PFHxS.
Analytical Column: HALO® PFAS, 2.7 µm, 2.1 x 100 mmDelay Column: HALO® PFAS Delay, 3.0 x 50 mmMobile Phase A: 20 mM Ammonium Acetete B: MethanolGradient: Time %B 0.0 20 15 90 20 90
Flow Rate: 0.4 mL/minPressure: 505 barTemperature: 44 °C
Detection: -ESI MRMInjection Volume: 2.0 µLSample Solvent: Methanol (96%) Water (4%)LC System: Agilent Triple Quadrupole LC/MS 6400
TEST CONDITIONS
PEAK IDENTITIES
1 PFBA
2 PFMPA
3 PFPeA
4 PFBS
5 PFMBA
6 PFEESA
7 NFDHA
8 4:2FTS
9 PFHxA
10 PFPeS
11 HFPO-DA
12 PFHpA
13 PFHxS
14 ADONA
15 6:2FTS
16 PFOA
17 PFHpS
18 PFNA
19 PFOS
20 9CI-PF3ONS
21 8:2FTS
22 PFDA
23 NMeFOSAA
24 NEtFOSAA
25 PFUnA
26 11CI-PF3OUdS
27 PFDoA
28 PFTrA
29 PFTA
4x10
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
3.2
3.4
-ESI TIC MRM Frag=166.0V (** -> **) Well_05.d
1 1
4x10
00.05
0.10.15
0.20.25
0.30.35
0.40.45
0.50.55
0.60.65
0.70.75
0.80.85
0.90.95
11.05
1.11.15
1.2-ESI MRM Frag=166.0V [email protected] (399.0 -> 80.0) Well_05.d
11.457
11.031
1 1
Counts vs. Acquisition Time (min)1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
12
34,5 6
78
9
1011
12
13,14
15
16
1718 19
20
21
22
23
24,25
26
27
28 29
Linear PFHxS
Branched PFHxS
5fused-core.comHALO and Fused-Core are registered trademarks of Advanced Materials Technology, Inc.
Figure 6. Rapid separation of 33 PFAS in under 5 minutes on a HALO® PFAS column.
1.0 2.0 3.0 4.0 5.00
50000
100000
150000
200000
250000
300000
350000
400000
450000
500000
550000
1 23
4
11
9
15
12,13
101487
65
29
30
3233
31
16
1820-22
19
2423
17
25-28
With all of the research being done on PFAS, a high throughput method is essential for both time and solvent savings. HALO® PFAS which utilizes Fused-Core® technology is well suited for rapid PFAS analysis. Figure 6 shows an efficient analysis of 33 PFAS in less than 5 minutes. These compounds comprise all of the target analytes in EPA methods 533, 537.1, and 8327.
Analytical Column: HALO® PFAS, 2.7 µm, 2.1 x 100 mmDelay Column: HALO® PFAS Delay, 3.0 x 50 mmMobile Phase A: 10 mM Ammonium Acetete B: MethanolGradient: Time %B 0.0 33 4.0 98 4.10 100 6.00 100 6.10 33 7.50 EndFlow Rate: 0.4 mL/minPressure: 479 barTemperature: 35 °CInjection Volume: 2.0 µLSample Solvent: Methanol (96%) Water (4%)
TEST CONDITIONS
Time (min)
PEAK IDENTITIES
1 PFBA
2 4:2FTS
3 PFPeA
4 PFBS
5 PFHpS
6 PFPeS
7 PFMPA
8 PFHxA
9 PFEESA
10 HFPO-DA
11 PFHxS
12 NaDONA
13 ADONA
14 FOSA
15 PFOA
16 PFMBA
17 PFHpA
18 PFOS
19 9Cl-PF3ONS
20 8:2FTS
21 PFNS
22 PFDA
23 N-MeFOSAA
24 PFNA
25 NFDHA
26 PFUnA
27 N-EtFOSAA
28 6:2FTS
29 11Cl-PF3OUdS
30 PFTrDA
31 PFDoA
32 PFTeDA
33 PFDS
6fused-core.comHALO and Fused-Core are registered trademarks of Advanced Materials Technology, Inc.
CONCLUSION
The combination of HALO® PFAS Delay and HALO® PFAS columns offers a complete solution for PFAS analysis. HALO® PFAS lots are quality assurance tested specifically with a mixture of 17 PFAS compounds. The HALO® PFAS Delay efficiently traps and delays PFAS from the LC system. Whether the goal is high resolution or high speed, HALO® PFAS columns deliver rugged, reproducible performance for the most challenging environmental sample matrices.
ORDERING INFORMATION:
ANALYTICAL COLUMNS
Dimensions: ID x Length (in mm) PN
2.1 x 50 92812-413
2.1 x 100 92812-613
2.1 x 150 92812-713
2.1 x 250 92812-913
3.0 x 50 92813-413
3.0 x 100 92813-613
3.0 x 150 92813-713
3.0 x 250 92813-913
DELAY COLUMNS
Dimensions: ID x Length (in mm) PN
3.0 x 50 92113-415
4.6 x 50 92114-415
SPECIFICATIONS
Column Particle Size (µm)
Surface Area (m2/g)
Low pH/T Limit
High pH/T Limit Endcapped
PFAS
Analytical2.7 135 9/40 °C 2/60 °C Yes
PFAS
Delay2.7 90 9/40 °C 2/60 °C Yes