☠️ Dioxins and PCBs (GC-HRMS)
In short
Determination of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and dioxin-like PCBs by high-resolution gas chromatography mass spectrometry (GC-HRMS). The test is performed according to PN-EN 1948-1:2006 + PN-EN 1948-4:2013+A1:2014; Mass spectrometer resolution: ≥ 10 000 R (10% valley definition). The procedure comprises 10 steps (about 8 h 15 min–20 h 45 min in total); it is used for: Monitoring of emissions from waste incineration plants, Food testing (meat, fish, milk, eggs) for compliance with EU limits, Analysis of animal feed for dioxin contamination.
At a glance
- Standard: PN-EN 1948-1:2006 + PN-EN 1948-4:2013+A1:2014
- Category: Environmental
- Procedure steps: 10
- Total time of stages: 8 h 15 min–20 h 45 min
- Mass spectrometer resolution: ≥ 10 000 R (10% valley definition)
- Limit of detection: 0.1–1 pg TEQ/g (food), 0.01 ng TEQ/Nm³ (emission)
- Number of congeners: 17 PCDD/PCDF + 12 dl-PCB = 29 analytes
Overview
Dioxins (PCDD/PCDF) and dioxin-like polychlorinated biphenyls (dl-PCBs) are among the most toxic anthropogenic substances — persistent organic pollutants (POPs) covered by the Stockholm Convention. Their determination requires the use of highest class analytical equipment — gas chromatography coupled with high-resolution mass spectrometry (HRGC/HRMS) with mass resolution ≥ 10 000.
Standard PN-EN 1948 defines methods for sampling and analysis of emissions from stationary sources (chimneys, incinerators), but GC-HRMS technique is also used for analysis of dioxins in food (Regulation (EU) 2023/915), feed, soil, sewage sludge and biological samples. Results are expressed in TEQ (toxic equivalent) using WHO-2005 toxicity equivalency factors (TEF).
The analytical procedure is extremely complex and costly — requires multi-stage extraction, cleanup on multilayer columns (silica, alumina, activated carbon), analysis on GC-HRMS with selected ion detection (SIM) and quantification by isotope dilution method (using ¹³C-labeled internal standards). Cost of single analysis is 3 000–8 000 PLN.
In Poland, dioxin analyses are performed by few laboratories, including Laboratory of Trace Analysis (dioksyny.pl), J.S. Hamilton Poland, ALS Poland and Institute of Environmental Protection. ISO 17025 accreditation in this area requires participation in interlaboratory comparison studies (e.g. INTERCAL).
Method principle
The method is based on isotope dilution — known amounts of ¹³C-labeled internal standards (17 PCDD/PCDF congeners and 12 dl-PCBs) are added to the sample. After extraction and multi-stage cleanup, the extract is analyzed on gas chromatograph with capillary column (DB-5ms or DB-Dioxin) coupled with magnetic sector mass spectrometer with resolution ≥ 10 000 R (10% valley). Detection in SIM (Selected Ion Monitoring) mode — molecular and fragment ions for each congener are monitored. Quantification based on ratio of analyte to ¹³C standard signals.
Applications
- Monitoring of emissions from waste incineration plants
- Food testing (meat, fish, milk, eggs) for compliance with EU limits
- Analysis of animal feed for dioxin contamination
- Monitoring of soils and sewage sludge in industrial areas
- Environmental sample testing (air, water, soil) near emission sources
- Population exposure assessment — analyses of breast milk, blood, adipose tissue
Key parameters
| Parameter | Value |
|---|---|
| Mass spectrometer resolution | ≥ 10 000 R (10% valley definition) |
| Limit of detection | 0.1–1 pg TEQ/g (food), 0.01 ng TEQ/Nm³ (emission) |
| Number of congeners | 17 PCDD/PCDF + 12 dl-PCB = 29 analytes |
| TEF factors | WHO-2005 (2,3,7,8-TCDD = 1.0) |
| Limit in food (meat) | 2.5 pg WHO-TEQ/g fat (PCDD/F), 5.0 pg (sum TEQ) |
| Analysis cost | 3 000–8 000 PLN / sample |
Standard
- Standard number
- PN-EN 1948-1:2006 + PN-EN 1948-4:2013+A1:2014
- Title (PL)
- Emisje ze źródeł stacjonarnych — Oznaczanie stężenia masowego PCDD/PCDF i dioksynopodobnych PCB
- Title (EN)
- Stationary source emissions — Determination of the mass concentration of PCDDs/PCDFs and dioxin-like PCBs
Step-by-step procedure
-
Addition of internal standards
Add known amounts of ¹³C-labeled internal standards PCDD/PCDF and dl-PCB to sample (10–50 g). Mix.
-
Extraction
Perform toluene-acetone extraction (Soxhlet 16h or ASE). For liquid samples — liquid-liquid extraction.
-
Cleanup — acidic column
Pass extract through multilayer silica column (acidic H₂SO₄ layer, basic KOH, neutral). Elution with hexane.
-
Cleanup — alumina column
Pass through aluminum oxide column. Elution: fraction 1 (hexane — discard), fraction 2 (DCM/hexane — collect).
-
Cleanup — carbon column
Pass through activated carbon AX-21 column on Celite. Separation of mono-ortho PCB from PCDD/PCDF and non-ortho PCB.
-
Concentration
Evaporate eluents to ~50 µL under nitrogen stream. Add recovery standards. Transfer to GC vial.
-
GC-HRMS analysis
Analysis on DB-5ms column (60 m). Temp program: 120°C→200°C (20°C/min)→280°C (3°C/min)→310°C (10 min). SIM mode, resolution ≥ 10 000.
-
Identification and quantification
Identify congeners based on retention time and isotope ratio (±15% of theoretical value). Calculate concentrations by isotope dilution method.
-
TEQ calculation
Multiply concentration of each congener by appropriate TEF (WHO-2005). Sum TEQ for PCDD/PCDF and dl-PCB separately and combined.
-
Quality control
Check recovery of internal standards (25–150%). Analyze blank sample, duplicate and CRM in each series.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| GC-HRMS (magnetic sector) | Thermo DFS, Waters AutoSpec Ultima, JEOL JMS-800D | 1 500 000–3 000 000 PLN |
| Automated extraction system (ASE) | Thermo Dionex ASE 350, Büchi SpeedExtractor E-916 | 100 000–200 000 PLN |
| Automated cleanup system | FMS PowerPrep, Fluid Management Systems | 200 000–400 000 PLN |
| Concentrator (evaporator) | Zymark TurboVap II, Büchi Syncore | 30 000–60 000 PLN |
| Cleanup columns (multilayer) | Silica columns (acidic/basic), alumina, activated carbon AX-21 | 500–2 000 PLN / disposable set |
| GC capillary column | Agilent DB-5ms (60 m × 0.25 mm × 0.25 µm), Restek Rtx-Dioxin2 | 2 000–4 000 PLN |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| ¹³C PCDD/PCDF standards (internal) | Mixture | Wellington Labs EPA-1613 LCS — 16 ¹³C-labeled PCDD/PCDF congeners, ~8 000 PLN / ampoule |
| ¹³C dl-PCB standards (internal) | — | Wellington Labs WP-LCS — 12 ¹³C-labeled dl-PCBs, ~5 000 PLN / ampoule |
| Native standards (calibration) | — | Wellington Labs EPA-1613 CS1–CS5 — set of 5 concentrations for calibration curve |
| Toluene (pesticide grade) | 108-88-3 | Purity ≥ 99.9%, Merck Suprasolv, for extraction and GC analysis |
| Hexane (pesticide grade) | 110-54-3 | Purity ≥ 99%, for cleanup on silica columns |
| Dichloromethane (pesticide grade) | 75-09-2 | Purity ≥ 99.9%, for extraction and elution from cleanup columns |
| Concentrated sulfuric acid | 7664-93-9 | For preparation of acidic layer of silica column (44% H₂SO₄ on silica) |
| Activated carbon AX-21 | — | For separation of planar PCB fraction from PCDD/PCDF on carbon column |
Health and safety (OHS)
- Toluene, hexane, DCM — toxic, flammable — work exclusively under fume hood
- Concentrated sulfuric acid — highly corrosive, exothermic reaction with water — glasses, acid-resistant gloves
- Dioxin standards — extremely toxic substances, work in designated area with full PPE
- Waste containing dioxins — disposal by incineration at temperature > 1200°C
- GC-HRMS with magnetic sector — strong magnetic field, prohibited for people with pacemakers
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN 1948-1:2006 + PN-EN 1948-4:2013+A1:2014 — “Stationary source emissions — Determination of the mass concentration of PCDDs/PCDFs and dioxin-like PCBs”.
How does this method work?
The method is based on isotope dilution — known amounts of ¹³C-labeled internal standards (17 PCDD/PCDF congeners and 12 dl-PCBs) are added to the sample. After extraction and multi-stage cleanup, the extract is analyzed on gas chromatograph with capillary column (DB-5ms or DB-Dioxin) coupled with magnetic sector mass spectrometer with resolution ≥ 10 000 R (10% valley).
What is the measuring range and accuracy?
Mass spectrometer resolution: ≥ 10 000 R (10% valley definition); Limit of detection: 0.1–1 pg TEQ/g (food), 0.01 ng TEQ/Nm³ (emission); Number of congeners: 17 PCDD/PCDF + 12 dl-PCB = 29 analytes; TEF factors: WHO-2005 (2,3,7,8-TCDD = 1.0).
How long does the test take?
The times given for the individual stages add up to approximately 8 h 15 min–20 h 45 min. The procedure comprises 10 steps.
What equipment is required?
GC-HRMS (magnetic sector), Automated extraction system (ASE), Automated cleanup system, Concentrator (evaporator), Cleanup columns (multilayer), GC capillary column. Indicative cost of the core instrument (GC-HRMS (magnetic sector)): 1 500 000–3 000 000 PLN.
Where is this test used?
Monitoring of emissions from waste incineration plants; Food testing (meat, fish, milk, eggs) for compliance with EU limits; Analysis of animal feed for dioxin contamination; Monitoring of soils and sewage sludge in industrial areas; Environmental sample testing (air, water, soil) near emission sources; Population exposure assessment — analyses of breast milk, blood, adipose tissue.
What safety precautions apply?
Toluene, hexane, DCM — toxic, flammable — work exclusively under fume hood; Concentrated sulfuric acid — highly corrosive, exothermic reaction with water — glasses, acid-resistant gloves; Dioxin standards — extremely toxic substances, work in designated area with full PPE; Waste containing dioxins — disposal by incineration at temperature > 1200°C; GC-HRMS with magnetic sector — strong magnetic field, prohibited for people with pacemakers.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN 1948-1.