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Method Statement for the Determination of Dioxins (PCDD/Fs)

Contents

Introduction
Principle
Performance Characteristics
Range of Application
Limit of Detection
Analytical Quality Control
References

Introduction

The performance of this method is validated in accordance with internationally recognised procedures.

This procedure describes the determination of the 17 2,3,7,8 chlorinated dibenzo dioxins and dibenzo furans by isotope dilution high resolution gas chromatography-mass spectrometry. Methods are based on, Method 23A and BS EN 1948:2006 and are within the scope of SAL's UKAS accreditation.

Solid/Liquid Samples: The method is an in-house protocol fulfilling the requirements of US EPA Method 1613

M23 Stack Emission Samples: The method is an in-house protocol fulfilling the requirements of US EPA Method 23A

BS EN 1948 Stack Emission Samples: The method is an in-house protocol fulfilling the requirements of method BS/EN 1948:2006 parts 1-3.

Principle

An aliquot of the sample is spiked with isotopically labelled internal standards and then the semi-volatile organic compounds are extracted into a solvent. These extracts are then concentrated by evaporation and analysed by High Resolution Gas Chromatography-High Resolution Mass Spectrometry (HRGC/HRMS). Deuterated internal standards are added to all test samples, spikes and blanks before analysis. The quantitative results are then corrected for the recovery of these standards.

Solid samples

Including (but not restricted to): soil, ash, feedstuffs, stack emission, ambient air emission samples

0.05 to 20 g sample aliquots are taken (matrix dependent), spiked with labelled internal standards, then soxhlet extracted with appropriate organic solvent. The extract is concentrated and subjected to "Combination/Florisil Column" purification. The purified extract is concentrated to 10-30 ul, spiked with labelled recovery standards and analysed by HRGC/HRMS.

Liquid samples

0.2 to 1 l sample aliquots are taken, spiked with labelled internal standards and subjected to liquid-liquid extraction with organic solvent. The extract is concentrated and subjected to "Combination/Florisil Column" purification. The purified extract is concentrated to 10-30 ul, spiked with labelled recovery standards and analysed by HRGC/HRMS.

Stationary Source Emissions

The XAD resin/PUF and associated filter are spiked with labelled internal standards, then soxhlet extracted with appropriate organic solvent.

Associated organic washings are concentrated to near dryness and mixed with the soxhlet raw extract.
Associated aqueous washings are subjected to liquid-liquid extraction with organic solvent and combined with the soxhlet raw extract

The combined raw extract is concentrated and subjected to "Combination/Florisil Column" purification. The purified extract is concentrated to 10-30 ul, spiked with labelled recovery standards and analysed by HRGC/HRMS.

Other matrices

PCDD/F content of other matrices such as chemical products, (e.g., chlorophenol based preparations), biological/food/feed matrices with a high fat content e.g. human adipose and eggs, milk and blood may also be determined by this method

Performance Characteristics

Substances Determined

The 17 toxic 2,3,7,8 chlorinated dibenzo dioxins and dibenzo furans and the total of all other congeners

Range of Application

• Solid samples 0.20 to 900 ng / kg

• Aqueous samples 0.05 to 200 ng / l

• Emission Samples 0.005 to 20 ng

Limit of Detection

• Solid samples 0.2 ng / kg (0.2ppt) for 10 g sample

• Stack emission 3-5 pg in whole sample, 0.6-1.0 pg/m 3 for 5 m 3

• Ambient air sample 3-5 pg in whole sample, 3-5 fg/m 3 for 1000 m 3

• Aqueous samples 0.05 ng / l (5pg/l), for 500 ml sample

Limits of detection can vary according to sample aliquot, internal standard recovery and matrix interference. The internal standard recovery and/or degree of interference can only be assessed on completion of the work. Therefore, the above figures are for guidance

Analytical Quality Control

Analytical quality control is maintained by a number of measures:

• Multi-point calibration with authentic standards (with defined minimum performance characteristics)

• Analysis of reagent/method blanks within each analytical batch

• Ongoing quality assured by the use of labelled internal standards and sample by sample recovery calculation

• Participation in external proficiency testing and interlaboratory schemes such as CSL FAPAS

References

• Method 23A: Determination of Polychlorinated Dibenzo-p-Dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) from Stationary Sources", US EPA, Revision 1, December 1996.

• Method 1613: "Tetra- through Octa- Chlorinated Dioxins and Furans by Isotope Dilution HRGC/HRMS, Revision B", pubd. United States Environmental Protection Agency Office of Water Regulations and Standards, Industrial Technology Division, Office of Water, October 1994.

• BS/EN 1948:2006-1,2 and 3, 2006. 'Stationary source emissions-Determination of the mass concentration of PCDDs/PCDFs'.

• Method Implementation Document (MID 1948), "BS EN 1948 Parts 1-3: 2006, Stationary source emissions - Determination of the mass concentration of PCDDs/PCDFs and dioxin-like PCBs. Part 1: Sampling of PCDDs/PCDFs, Part 2: Extraction and clean-up of PCDDs/PCDFs, Part 3: Identification and quantification of PCDDs/PCDFs" Environment Agency,

• Ambridge, P.F. et al , "Acceptance Criteria for analytical data on polychlorinated dibenzo- p -dioxins and polychlorinated dibenzofurans", Chemosphere , 21 (8): 999-1006, (1990).

• COMMISSION DIRECTIVE 2002/69/EC. of 26 July 2002, laying down the sampling methods and the methods of analysis for the official control of dioxins and the determination of dioxin-like PCBs in foodstuffs

• COMMISSION DIRECTIVE 2002/70/EC of 26 July 2002 establishing requirements for the determination of levels of dioxins and dioxin-like PCBs in feedingstuffs

• BS/ISO 18073:2004 Water quality - Determination of tetra to octa-chlorinated dioxins and furans - Method using isotope dilution HRGC/HRMS

• FOOD SAMPLES CLEAN-UP USING SEMIPERMEABLE POLYETHYLENE MEMBRANES (SPM) FOR THE DETERMINATION OF POLYBROMINATED DIPHENYL ETHERS, Adam Jan Grochowalski, Dominika Wojtalewicz, presented at Dioxin 2005, Toronto, August 2005.