EPA Method 1633 Instrumentation Guide
LC-MS/MS for PFAS Analysis
EPA Method 1633A is the U.S. EPA’s multi-laboratory validated method for measuring 40 per- and polyfluoroalkyl substances (PFAS) in wastewater, surface water, groundwater, landfill leachate, soil, sediment, biosolids and fish tissue. The EPA Office of Water developed it with the U.S. Department of Defense, and the December 2024 revision supersedes all earlier versions of Method 1633. EPA recommends it for PFAS monitoring under NPDES permits.
Aqueous samples are extracted by solid-phase extraction (SPE) and cleaned up with carbon. Solids are extracted into basic methanol, and tissue into potassium hydroxide and acetonitrile followed by basic methanol, before the same SPE and carbon cleanup. Extracts are analyzed on a triple quadrupole LC-MS/MS in negative electrospray, multiple reaction monitoring (MRM) mode, and isotopically labeled standards added before extraction correct each result for losses during preparation.
Looking for an LC-MS/MS system for EPA Method 1633A? Browse refurbished LC-MS systems or request a configuration quote.
EPA Method 1633A Summary
| Item | Detail |
|---|---|
| Method | EPA Method 1633, Revision A, December 2024 (EPA 820-R-24-007) |
| Analytes | 40 PFAS across nine classes, including PFCAs, PFSAs, fluorotelomer sulfonates, sulfonamides and ether acids such as HFPO-DA (GenX) |
| Matrices | Wastewater, surface water, groundwater, landfill leachate, soil, sediment, biosolids, fish and shellfish tissue |
| Technique | WAX solid-phase extraction with carbon cleanup, then isotope dilution LC-MS/MS on a triple quadrupole (negative ESI, MRM) |
| Sample and solvent | 500 mL aqueous (100 mL leachate), 5 g soil or sediment, 0.5 g biosolids, 2 g tissue; solids extracted into basic methanol |
| Injection | 2.0 µL default, identical for all standards, samples and QC |
| Working range | At least six calibration standards (linear) or seven (second-order), with the lowest at or below the lab’s LOQ |
| MDL | Example pooled MDLs for PFOS: 0.63 ng/L (aqueous), 0.07 ng/g (solids); each lab sets its own |
| Extraction and analysis time | 12.0-minute LC gradient program per injection; the method does not state an extraction time |
Labs may add PFAS beyond the 40 listed when authentic standards are available (Section 1.6). EPA recommends Method 1633A for NPDES monitoring; it was proposed for 40 CFR Part 136 in December 2024.
Instrument requirements
Method 1633A specifies a UHPLC or HPLC system coupled to a triple quadrupole mass spectrometer. The settings below are the method’s example conditions; equivalent columns and instruments are allowed if they meet the method’s performance criteria.
| Setting | Method 1633A requirement |
|---|---|
| Mass spectrometer | Triple quadrupole, at least 10 scans across each peak |
| Ionization | Negative electrospray (ESI−) |
| Acquisition | Multiple reaction monitoring (MRM), unit mass resolution |
| LC system | UPLC or HPLC |
| Analytical column | C18, 1.7 µm, 50 × 2.1 mm (Waters ACQUITY UPLC BEH or equivalent) |
| Guard column | Phenomenex Kinetex EVO C18 or equivalent |
| Delay column | Purospher STAR RP-18 endcapped, 3 µm, Hibar RT 50-4 or equivalent |
| Column temperature | 40 °C |
| Mobile phase A | Acetonitrile |
| Mobile phase B | 2 mM ammonium acetate in 95:5 water/acetonitrile |
| Gradient | About 12 minutes at 0.35–0.40 mL/min; up to 1,100 bar |
| Mass calibration | At least annually, or as the manufacturer recommends |
The method lists a trap/delay column with the LC equipment and notes that LC system components, as well as the mobile phase, may contain many of the analytes in this method.
Know the configuration you need? Request an EPA 1633A LC-MS/MS quote.
What to look for in a refurbished LC-MS/MS system
The right refurbished system combines the required hardware with evidence that it performs reliably. Use these checks when comparing systems.
| System area | Method 1633A need | What to check |
|---|---|---|
| Mass spectrometer | Triple quadrupole, MRM, unit mass resolution, at least 10 scans per peak | Mass calibration within the past year and a passing instrument sensitivity check at the lab’s LOQ |
| Ion source | Negative electrospray | Operation in negative ESI mode |
| LC pump | 12.0-minute gradient at 0.35–0.40 mL/min, column at 40 °C | Pressure rating compared with the method’s 1,100 bar maximum |
| Autosampler | Same injection volume for every standard, sample and QC | Consistent injection volume across the analytical sequence |
| Columns | C18 analytical, guard and trap/delay columns | Trap/delay column included in the LC configuration |
| PFAS background | Instrument blanks below each analyte’s MDL equivalent | Instrument blank results, run at the start of each sequence and after high-concentration samples |
| Documentation | Mass calibration at least annually | Mass calibration records |
Need help comparing systems? Tell our team about your sample matrices, reporting limits and preferred platform. Talk to an instrument specialist or call (844) AMP-TECH.
Example LC-MS/MS configurations
The platforms below are examples that may be configured for EPA Method 1633A. The method names the Waters Xevo TQ-S micro “or equivalent” as its example but doesn’t require a specific brand or model, so the choice can reflect your budget, platform preference and service needs.
| Platform | Configuration for Method 1633A | Key Benefits for EPA 1633A |
|---|---|---|
| ACQUITY I-Class UPLC | The example instrument named in Method 1633A | |
| Vanquish UHPLC | Triple quadrupole designed for targeted quantitation | |
| 1200/1260 Infinity or 1260 Infinity II | iFunnel technology, including Agilent Jet Stream, for more efficient ion sampling | |
| 1260 HPLC | Agilent Jet Stream technology at a lower purchase price | |
| 1260 Infinity II | Compact, stackable triple quadrupole design |
Some listed systems ship with LC front ends or detectors Method 1633A doesn’t use, but our team can help you plan an EPA Method 1633A configuration. We’ll review the LC front end, columns and trap/delay column with you before you buy.
Don’t see the right configuration in the store? Tell us what you need, and we’ll check the available options.
Choosing a configuration
Start with your sample types and reporting limits.
- Sample types: aqueous, solid and tissue samples all need SPE and carbon cleanup; solids and tissue are extracted first, then go through the same cleanup.
- Example configuration: the method names the Waters Xevo TQ-S micro and an Acquity UPLC BEH C18 column, each “or equivalent.”
- Delay column: plan for a trap/delay column in the LC system, as the method lists.
- Reporting limits: each lab sets its own MDLs and LOQs and must pass the instrument sensitivity check at its LOQ before each sequence. Browse refurbished LC-MS systems.
Amptius Certified Refurbished Instruments
AMP Tech offers refurbished analytical instruments and can help you configure a refurbished LC-MS/MS system for EPA Method 1633A. Amptius Certified refurbished instruments go through a six-stage certification process, including repair, analytical testing, and documentation before shipment, giving your lab a lower-cost alternative to buying new.
Certified instruments include a 6-month limited warranty covering parts and labor for covered defects in materials or workmanship.
AMP Guard Service Plans
For support beyond the warranty, AMP Guard offers optional service plans with remote support, service facility repair, and on-site options. Coverage depends on the plan and instrument.
Request a quote with your sample volume, confirmation approach, and preferred platform. Our documentation and technical support can help your team prepare for method validation and ongoing QC.
Sell or Trade in your lab equipment
Upgrading your lab or clearing surplus equipment? AMP Tech buys GC/MS, LC/MS and triple quad, HPLC, ICP-OES and ICP-MS, and FTIR and spectroscopy systems, along with supporting lab equipment. We buy everything from a single instrument to an entire lab, anywhere in the country.
You get a firm, no-obligation offer within 48 hours with no fees or commission. Our team handles decommissioning, packing, and removal, and you can apply your equipment’s value toward an Amptius Certified instrument.
Sell your equipment or check your trade-in value.
Sources
- EPA Method 1633, Revision A (December 2024)
- EPA: CWA Analytical Methods for PFAS
- EPA: Frequent Questions about PFAS Methods for NPDES Permits
- EPA: Clean Water Act Methods Update Rules
- Waters Xevo TQ-S micro specifications
- Thermo Scientific TSQ Quantis product page
- Agilent 6400 Series Triple Quad LC/MS Concepts Guide (6490 and 6460)
- Agilent LC/TQ product comparison data sheet (Ultivo)
