Method for Mercury Determination

Speciation for Validation Measurements of a Method for Determination of Mercury in Ambient Air and Deposition

Funded by: EC DG Environment/NEN/CEN/CMC/DIN

(Contr. No. CENT/TC 264/WG 25/335)

Period: September 2006-December 2008

Environment

28 mesi

Concluso

Introduzione

The objective considered in the Sixth Environment Action Programme is to achieve levels of air quality that do not give rise to unacceptable impacts on, and risks to, human health and the environment. The Community is acting at many levels to reduce exposure to air pollution: through EC legislation, through work at the wider international level in order to reduce cross-border pollution, through working with sectors responsible for air pollution and with national, regional authorities and through research. Mercury is a particularly insidious and difficult pollutant to manage. Its ability to exist in several physical states and chemical forms at commonly-encountered conditions of temperature and pressure, and propensity to undergo biological transformations, means that it is subject to complex and difficult-to-predict changes in concentration and form. Environmental monitoring studies thus must consider a variety of physical changes, geochemical reactions, and biochemical interactions in an attempt to understand the specific local conditions that contribute to mercury levels found in different environmental ecosystems.

To assess how much mercury is present in air, water, soil, biota and other environmental ecosystems several measurements have been performed on global scale using a variety of sampling methods and analytical techniques which are just now becoming available and are seeing limited use in research projects. However, the application of different sampling and analytical methods could lead to results that are not equivalent. European Union policy on air quality aims to develop and implement appropriate – standard methods – for the assessment of the air quality. The general aim of the “Framework Directive” (FWD) is to define the basic principles of a common strategy in order to assess the following objectives:

  • To define and establish objectives for ambient air quality in the Community (for 13 air polluting substances including mercury) designed to avoid, prevent or reduce harmful effects on human health and the environment as a whole;
  • To assess the ambient air quality in Member States on the basis of common methods and criteria;
  • To obtain adequate information on ambient air quality and ensure that it is made available to the public, inter alia by means of alert thresholds;
  • To maintain ambient air quality where it is good and improve it in other cases.

he quality objectives and the assessment methods are established by “Daughter Directives” 2004/107/EC relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air published in January 2005.

Following the requirements of the 4th Daughter Directive, Member States will have to measure the Total Gaseous Mercury (TGM) in the ambient air and the Total Deposition of Mercury. Several European laboratories perform determination with manual and automated methods for assessing ambient concentrations of TGM and the deposition of fluxes of mercury through wet and dry deposition pathways. Therefore, there is a strong need to elaborate fully validated and traceable European standard methods that will ensure the representativeness , comparability , accuracy and precision of data measured by all Member States and the adoption of standard QA/QC protocol. The availability of standardized methods will therefore be fundamental to an efficient implementation of EC legislation on ambient air quality and to harmonise the present air quality data.

There is currently no standard method for the determination of the ambient concentration of Total Gaseous Mercury. At this stage only the European standard method for the determination of the mercury concentration in water samples (EN 13506) exists but no standard method exists for the determination of mercury in precipitation, though OSPAR/EMEP reference methods are currently available for TGM and mercury in precipitation.

The standardised method for the measurement of Total Gaseous Mercury concentrations in ambient air shall be an automated method based on sampling by gold traps and analysis by Cold Vapour Atomic Absorption Spectrometry/Cold Vapour Atomic Fluorescence Spectrometry.

Project Plan

The technical work includes the validation tests for Total Gaseous Mercury (TGM) and mercury deposition. In order to validate a method, it shall be necessary to know the performance of the method and, therefore, to characterize it through the evaluation of some characteristics (i.e. specificity/selectivity, repeatability/reproducibility, linearity, limit of the detection). Methods for TGM concentrations as well as different types of deposition samplers (bulk, Bergerhoff and wet-only) need to be tested and the experiments for their evaluation will be defined and optimised. Sampling and analytical methods will be tested over a 12 months period at both local/industrial and background (coastal/rural) sites. To validate the drafted method the field tests will be carried out at four different European measurement sites (2 local/industrial and 2 remote/background). The field validation tests will last two months at each of the four stations.

 

Total Gaseous Mercury (TGM) in Ambient Air

The instruments shall be located at four locations in Europe (two coastal/background and two local/industrial sites). Site requirements shall be in accordance with the description in Directive 2004/107/EC. The working range of a standardised method should, in fact, cover ambient air concentrations at background sites (coastal/rural) and at local/industrial sites in order to establish technical procedures that provide results of quality over a wide range of application (concentration levels for which the methods apply). It is foreseen to perform the inter-comparison at two background sites and at two local/industrial sites. For coastal/rural sites an EMEP type station is preferable in order to reduce contamination risks. The location of the sites shall account for differences in aerosol composition (i.e., Saharan dust, urban, continental, marine), prevailing meteorological conditions and type of emission sources (i.e., coal combustion, chlorine-alkaline, solid waste incinerators). Therefore it is foreseen that the two coastal/background sites shall be located one in Southern Europe and one in Northern Europe, whereas the two local/industrial sites shall be located in areas characterised by different types of emission sources, in particular one located nearby a coal power plant where the majority of mercury emissions is in the gaseous elemental form (Hg 0 ) (> 50%), and a second site shall be located near an incinerator for waste disposal or chlorine-alkaline plant which are both representative of high emission rates (> 60%) of oxides mercury compounds (i.e., HgCl 2).

 

TGM measurements will take place at the following sites:

  • One Central/Northern European remote/background site (inland);
  • One Central/Northern European industrial site (near a coal power plant);
  • One Southern European remote/background site (coastal);
  • One Southern European industrial site (near a chlorine-alkaline or incinerator facility);

For each sites one laboratory (lab A, B , C, D) will be responsible.

  • Lab. A: Italy (CNR-Institute for Atmospheric Pollution, Rende) Will operate and run the Southern European remote/background site (coastal site).
  • Lab. B: Spain (Instituto de Salud Carlos III, Madrid) Will operate and run the Southern European industrial site (near a chlorine-alkaline or incinerator facility).
  • Lab. C: Sweden (IVL) Will operate and run the Central/Northern European remote/background site (coastal site).
  • Lab. D: Belgium (VMM) Will operate and run the Central/Northern European industrial site (near a coal power plant).

Mercury Deposition

Different types of deposition samplers like Bulk, Bergerhoff and wet-only samplers will be used to obtain parallel precipitation samples for mercury analysis.

It is proposed that equipment currently used in Europe will be tested for two times 6 months. Two Wet only, two Bulk samplers and four Bergerhoff samplers shall be operated in parallel in order to perform duplicate measurements. Deposition samplers will be used to collect for a 6 months sampling period enough precipitation volumes for analysis by at least two laboratories to perform an extensive inter-comparison analysis exercise. The aim of the inter-comparison is to evaluate the reproducibility of bulk, Bergerhoff and wet-only sampling as well as compare the sampling methods.

Samples will be collected on weekly basis for the Bulk and Wet only, and 4 weekly for the Bergerhoff. The equipment shall be located at one remote (coastal/rural) site and one local (urban/industrial) station. The sampling stations will be managed by qualified personnel involved in the Working Group. Therefore it is foreseen that the whole validation tests will involve two laboratories, one for each site. For the coastal/rural site an EMEP type station is preferable in order to reduce contamination risks. A full detailed QA/QC report on the results obtained by bulk, Bergerhoff and wet-only samplers will be provided.

  • 20% of Bulk samples will be sent to a second laboratory of the participating laboratories;
  • 20% of Wet only samples will be sent to a second laboratory of the participating laboratories;
  • 20% of the Bergerhoff samples will be sent to a second laboratory of the participating laboratories.

It is proposed, that the following laboratories will be responsible for the execution of the above described field tests:

  • Lab A: Slovenia (IJS) with contribution of PSA&UBA to analyse 20% of samples
  • Lab B: Sweden (IVL) with contribution of PSA&UBA to analyse 20% of samples

Objectives

Although there are different automated and manual techniques available for determining TGM concentrations in ambient air, there is no standardised method to produce measurement data of a known and verifiable quality and which are of quality sufficient to meet overall objectives of the air quality monitoring investigation. At this stage only the European standard method for the determination of the mercury concentration in water samples (EN 13506) exists but no standard method exists for the determination of mercury in precipitation.

The availability of standardized methods for TGM in ambient air and mercury deposition will be fundamental to an efficient implementation of EC legislation on ambient air quality and to harmonise the present air quality data.

The general objective is to elaborate fully validated and traceable European standard methods for TGM in Ambient Air and Total Mercury in precipitation samples that will ensure the representativeness , comparability, accuracy and precision of data measured by all Member States and the adoption of standard QA/QC protocol.

Research Strategy

TOTAL GASEOUS MERCURY (TGM)

WP-1: Laboratory Tests

Each laboratory will provide the preparation, coordination and reporting including statistical evaluation of the laboratory tests. Cross check of performance characteristics of all TGM analyzers. It is foreseeen to test all automated TGM samplers currently used in Europe (see A.4.6), possibly, two parallel instrument for each type. Preparation of TGM analyzers, including all necessary (installation and mantainance, calibration, detection limit, cleaning and check collection efficiency and recovery of gold trap inside TGM analyzers, control of blank values, sampling and analysis, accuracy and precision, comparability, representativeness and QA/QC, and reporting) and shipping operations of both authomated TGM analyzers and TGM-gold-traps to the sites/back to the provider.

Deliverables

Report on the laboratory tests consisting of a technical part and results obtained under WP-1 (i.e., blank values and the detection limit).

WP-2 and WP-3: Preparation of field tests and Field validation tests

Operation and running of a Central/Northern European (WP-2) and a Southern European industrial (near a chlorine-alkaline or incinerator facility) (WP-3) industrial (near a coal power plant) sampling site including two continuous TGM Analyzers at both sampling sites. The TGM measurements have to be taken on 5 minutes increments and each of the laboratories will make available TGM data to the WP-6 for statistical evaluation. Shipping of analyzers to the next site/back to the provider. The total cost include all necessary (installation and maintenance of all samplers and the determination of automatic mercury concentrations, QA/QC and reporting). The costs in addition include all necessary concerning personnel involved.

Deliverables

Report on the preparatory field tests consisting of a technical part and results obtained under WP-2 and WP-3.

WP-4 and WP- 5: Preparation of field tests and field Validation Tests

Operation and running of a Central/Northern European remote/background (inland) and a Southern European remote/background (coastal) sampling sites including two continuous TGM Analyzers at both sites. The TGM measurements have to be taken on 15 minutes increments and each of the laboratories will make available TGM data to the WP-6 for statistical evaluation. Shipping of analyzers to the next site/back to the provider. The total cost include all necessary (installation and maintenance of all samplers and the determination of automatic mercury concentrations, QA/QC and reporting). The costs in addition include all necessary concerning personnel involved.

Deliverables

Report on the preparatory field tests consisting of a technical part and results obtained under WP-4 and WP-5.

WP-6: Statistical evaluation of TGM data

A report on statistical analysis of all TGM data obtained at each site including all field validation tests for each instrument, and time series data of TGM data obtained at each of the four sites. The report on automated TGM sampling and analysis will deal with the performance characteristics of the automated analyzers as well as of the single analytical line (it refers to the single gold trap line used in the instrument and will include information on its linearity, stability, span, etc.) used in the automated instrument. The report, in particular, will provide information on the reproducibility between different automated instruments and intercomparison between laboratories for automated methods. The report will contain also a technical chapter describing each sampling and analytical procedure for TGM instruments used and a detailed QA/QC information for each automated instruments will also be given.

MERCURY DEPOSITION

WP-1 and WP-2:

Operation of an European local/industria l and an European remote/background sampling sites including two wet-only, two bulk and four Bergerhoff samplers for each sampling site. The wet-only and the bulk samples have to be taken on weekly basis, the Bergerhoff on four weekly basis; the samples shall be shipped to the laboratory performing the samples analays. The operation of the site includes all steps involved in the samplers preparation (i.e., acid clean of all parts involved in the sampling). A report of the sampling programme and results shall be provided.

WP-3 and WP-3b:

Analysis of wet-only samples received from both the local/industrial and remote/background sampling site (WP-1 and WP-2) (using the analytical methods described in EN 13506). Up to 60 samples for each station have to be analyzed including blanks. Report on samples analysis and QA/QC shall be provided.

WP-4a and WP-4b:

Analysis of bulk samples received from both the local/industria l and remote/background sampling sites ( WP-1 and WP- 2) (using the analytical methods described in EN 13506). Up to 60 samples for each station have to be analyzed including blanks. Report on samples analysis and QA/QC shall be provided.

WP-5a and WP-5b:

Analysis of four identical Bergerhoff samples received from each of the local/industria l and remote/background sampling sites ( WP-1 and WP- 2) (using the analytical methods described in EN 13506). Up to 25 samples for each station have to be analyzed including blanks. Report on samples analysis and QA/QC shall be provided.

WP-6:

Statistical and technical evaluation of data and establishing final laboratory and field validation report. This work package covers the overall evaluation and description of the field validation tests which are performed at two European measurement sites. The report should at least include: description of the sampling sites, sampling programme (technical info, results, validation), transport, sampling preparation and analytical methods, deposition results, data calculations/interpretation/comparison of results (QA/QC results, real samples, and a conclusion.

Partnership

  • CNR-Institute for Atmospheric Pollution (CNR-IIA), Italy – COORDINATORE
  • Vlaamse Milieumaatschappij (VMM), Belgium
  • Institute Salud Carlos III (ISC) Centro Nacional de Sanidad Ambiental, Spain
  • CNational Physical Laboratory (NPL), UK
  • Institut Jozef Stafan – (IJS) Department of Environmental Sciences, Slovenija   
  • Swedish Environmental Research Institute IVL, Sweden

Members CEN/TC 264/WG 25

  • CNR-Institute for Atmospheric Pollution (CNR-IIA), Italy
  • Nederlands Normalisatie-Instituut (NEN) – Netherlands Standardization Institute, Germany
  • Norwegian Institute for Air Research (NILU), Norway 
  • Umweltbundesamt, Germany
  • EC – DG (JRC) – Institute for Environment and Sustainability, Italy
  • National Physical Laboratory (NPL), UK
  • Vlaamse Milieumaatschappij (VMM), Belgium 
  • AEA Technology, UK
  • Hungarian Standards Institution (MSZT), Hungary
  • Institute Salud Carlos III (ISC) Centro Nacional de Sanidad Ambiental, Spain 
  • Umweltbundesamt GmbH Air Quality Control, Austria
  • Institut Jozef Stafan – (IJS), Department of Environmental Sciences, Slovenija  
  • Health & Safety Laboratory, UKited Kingdom
  • Institut National de l’Environnement Industriel et des Risques (INERIS) Parc Technologique, France
  • National Institute for Public Health and the Environment (RIVM), The Netherland 
  • Kornyezetvèdelmi ès Vizugyi, Hungary 
  • Swedish Environmental Research Institute (IVL), Swedish 
  • Commission on Air Pollution Prevention KRdL, Germany
  • Keris Ltd., UK
  • PS-Analytical Instruments Ltd, UK

 

 

Francesca Sprovieri

Francesca Sprovieri

Project Coordinator

email: f.sprovieri@iia.cnr.it

Gruppo di lavoro

Nicola Pirrone

CNR-IIA

Natacha Claeys

VMM

Carmen Ramoz Diaz

ISC

 

 

Rosalia Fernandez

ISC

Saul G. dos Santos-Alves

ISC

Richard Brown

NPL

Peter Woods

NPL

 

 

Milena Horvat

IJS

John Munthe

IVL

Ingvar Wangberg

IVL

Members CEN/TC 264/WG 25

Nicola Pirrone

CNR-IIA

Francesca Sprovieri

CNR-IIA

Caroline van Hoek

NEN

 

 

Torunn Berg

NILU

Elke Bieber

Umweltbundesamt

Annette Borowiak

JRC

Richard Brown

NPL

 

 

Peter Woods

NPL

Natacha Claeys

VMM

Peter Coleman

AEA

Gabriella Csik

MSZT

 

 

Carmen Ramoz Diaz

ISC

Rosalia Fernandez

ISC

Saul G. dos Santos-Alves

ISC

Marina Froehlich

Umweltbundesamt GmbH

 

 

Milena Horvat

IJS

Alan Howe

Health & Safety Laboratory

Fabrice Marliere

INERIS

Ton van der Meulen

RIVM

 

 

Gabor Motika

Kornyezetvèdelmi ès Vizugyi

John Munthe

IVL

Ingvar Wangberg

IVL

Rudolf Neuroth

KRdL

 

 

Kevin Saunders

Keris Ltd.

Peter Stockwell

PS-Analytical