The aim of WP1 is to establish and implement a traceable calibration methodology for the most important oxidised Hg species, especially for HgCl2. The calibration methods will be based on evaporation, sublimation and oxidation and this will include the measurement of the output of liquid evaporative generators, the development of real-time measurement techniques and the development of transfer gas standards.
The calibration methods and transfer gas standards developed in WP1 will be used to validate the measurement methods in WP2, the sampling methods in WP3 and in the on-line Hg field measurements in WP4.
The aims of the tasks in WP1 are to:
Task 1.1 develop a traceable calibration method for the most important Hg(II) species, including HgCl2, based on a validated method to accurately compare the Hg concentration in generated standard gases for Hg(0) and HgCl2.
Task 1.2 develop a method for the traceable generation of HgCl2 at µg/m3 levels for stack gas emission measurements, including a certification protocol for confirming the output of liquid evaporative HgCl2 generators
Task 1.3 develop transfer reference gas standards for atmospheric (oxidised) Hg measurements for the calibration of liquid evaporative HgCl2 generators at sub-ng/m3 levels
Task 1.1: Traceable calibration method
The aim of this task is to develop a traceable calibration method for the most important oxidised Hg species, i.e. HgCl2, based on a validated method to accurately compare the Hg concentration in generated standard gases for Hg(0) and HgCl2, whereby the response to Hg originating from Hg(0) and HgCl2 must be the same.
The task will focus on establishing the traceability of oxidised Hg using the Hg(0) generator which enables traceable Hg gas phase calibrations based upon gravimetry; developed in EMRP JRP ENV51 MeTra. Using this traceable Hg(0) generator the conversion steps in the traceability chain from the Hg(0) source (ENV51 MeTra) via HgCl2 or Hgtot will be characterised, optimised and described as follows:
- Hg(0) (ENV51 MeTra) → HgCl2 → Hg(0) (measurement) ↔ Hg(0) (ENV51 MeTra)
- Hg(0) (ENV51 MeTra) → (HgCl2 + Hg(0)) → HgTot (measurement) ↔ Hg(0) (ENV51 MeTra)
| Activity number | Activity description | Partners (Leadinbold) |
|---|---|---|
| A1.1.1 | Lumex with support from VTT, JSI and VSL will develop a two-channel analytical system (based on Zeeman atomic absorption spectrometry) capable of determining the concentration of both elemental Hg (Hg(0)) and oxidised Hg simultaneously in real time. The system will consist of an inlet compartment where analysed flow from a HgCl2 generator (or from another type of oxidised Hg generator) will enter. Part of this flow will be directed into the first analytical channel where the Hg(0) concentration will be measured. The other part of the flow will be directed into the second analytical channel where an atomiser (Cold Vapour (CV) or thermal) will measure the Hgtot concentration. | Lumex, VTT, JSI, VSL |
| A1.1.2 | PSA, VSL and JSI will develop a calibration method for the measurement of HgCl2 from liquid evaporative HgCl2 generators. The calibration method will be traceable to the primary Hg(0) generator developed within EMRP JRP ENV51 MeTra. As part of this catalyst materials and oxidation chambers will be developed to oxidise Hg(0). Oxidised Hg will be generated from spiked selective sorbent traps and continuous sources of Hg(0) from dynamic generators. The transfer (i.e. generation) of the generated oxidised Hg will be studied along with the effects of humidifying the carrier gas in order to improve transfer. For HgCEM applications a compliance system integrity check must be performed by introducing an oxidised Hg calibration gas at the tip of the probe. Therefore, a continuous source at flow rates of up to 20L/min of calibration gas will be developed using the primary Hg(0) generator from ENV51 MeTra. The accuracy and uncertainty budget for a commercially available HgCEM Hg(0) generator will be established against the primary Hg(0) generator from ENV51 MeTra. The commercial HgCEM generator (hired and operated by PSA) will then be used to deliver Hg(0) to the Hg oxidation catalyst materials and oxidation chambers that will be developed. Subsequently, this calibration method for the measurement of HgCl2 using a HgCEM generator will be compared to the accuracy and uncertainty budget established for commercially available evaporative HgCl2 generators. |
PSA, VSL, JSI |
| A1.1.3 | Lumex, with support from VTT, JSI and VSL, will develop software for the two-channel analytical system developed in A1.1.1. Using this software the data received from both analytical channels of the system will be processed in order to give the calculated concentrations of both Hg(0) and oxidised Hg in real time. Simultaneous detection of Hg(0) and oxidised Hg will allow the real analytical characteristics of a tested generator of oxidised Hg to be determined. | Lumex, VTT, JSI, VSL |
| A1.1.4 | VTT, with support from JSI, VSL, Optoseven, Lumex and PSA, will optimise the working parameters of a commercial liquid evaporative HgCl2 generator and at least 1 of Optoseven's newly developed oxidised Hg generators (based on Optoseven's experience in generating trace amounts of reactive gases). To do this, the calibration method for the measurement of HgCl2 from liquid evaporative HgCl2 generators from A1.1.2 and the two-channel analytical system from A1.1.1 with the software from A1.1.3 will be used. From the results, VTT, with support from JSI, VSL, Optoseven, Lumex and PSA, will produce optimised and traceable calibration methods for oxidised mercury (Hg) species, including mercury chloride (HgCl2). |
VTT, JSI, VSL, Optoseven, Lumex, PSA |
| A1.1.5 | VSL, with support from JSI, VTT, Optoseven, Lumex and PSA, will review the methods from A1.1.4, and the coordinator will then submit it to EURAMET as D1 ‘Optimised and traceable calibration methods for oxidised mercury (Hg) species, including mercury chloride (HgCl2)'. | VSL, JSI, VTT, Optoseven, Lumex, PSA |
Task 1.2: Validated methodology for stack gas emission measurements
The aim of this task is to develop a protocol for the traceable generation of HgCl2 at µg/m3 levels for stack gas emission measurements. As part of this, a certification protocol will be developed for confirming the output of liquid evaporative HgCl2 generators.
| Activity number | Activity description | Partners (Lead in bold) |
|---|---|---|
| A1.2.1 | Using input from A1.1.4, VSL, with support from VTT, JSI, Optoseven and PSA, will produce a protocol, analogous to the existing calibration method/certification procedure for Hg(0) generators, for stack gas emission measurements. This will be undertaken in collaboration with the project's Stakeholder Committee (A5.1.1). | VSL, VTT, JSI, Optoseven, PSA |
| A1.2.2 |
Optoseven, with support from VTT, JSI, VSL and PSA, will certify at least one field liquid evaporative HgCl2 generator using the protocol developed in A1.2.1. The field liquid evaporative HgCl2 generator that will be certified will be hired by VTT. The field liquid evaporative HgCl2 generator will be tested at the stack emission sites chosen in A4.1.1 and A4.1.2. Based on the results of the field tests undertaken in this activity, the certification protocol developed in A1.2.1 will be amended as necessary. |
Optoseven, VTT, JSI, VSL, PSA |
| A1.2.3 | Based on the results of A1.2.2, Optoseven, with support from VTT, JSI, VSL and PSA, will produce a certification protocol for confirming the output of liquid evaporative HgCl2 generators. | Optoseven, VTT, JSI, VSL, PSA |
| A1.2.4 | Optoseven, with support from VTT, JSI, VSL, and PSA, will review the certification protocol from A1.2.3, and the coordinator will then submit it to EURAMET as D2 ‘Certification protocol for the output of liquid evaporative HgCl2 generators'. | Optoseven, VTT, JSI, VSL, PSA |
Task 1.3: Traceable generation of mercury(II)chloride for atmospheric Hg measurements
The aim of this task is to develop a method for the on-site traceable generation of HgCl2 at sub-ng/m3 levels for atmospheric measurements. As part of this, a portable (transfer) reference gases will be developed for atmospheric (oxidised) mercury measurements. The traceability of the reference gases will be based on the primary Hg(0) generator from EMRP JRP ENV51 MeTra i.e.:
- HgCl2 (generator) → Hg(0) (measurement) ↔ Hg(0) (ENV51 MeTra)
- HgCl2 (generator) → HgTot (measurement) ↔ Hg(0) (ENV51 MeTra)
| Activity number | Activity description | Partners (Lead in bold) |
|---|---|---|
|
A1.3.1 |
VSL, VTT, JSI and Optoseven will develop a transfer gas standard for the calibration of liquid evaporative HgCl2 generators at sub-ng/m3 levels. This will be undertaken using input from the project's Stakeholder Committee A5.1.1 and input from A1.1.4, A1.1.5 and A1.2.3. The transfer gas standard will be based on the outcomes of A2.1.1 and A3.2.2 for producing and using a transfer gas standard loaded on selective sorbent traps, in order to enable comparable on-site (field) HgCl2 measurements. The traceability of the transfer gas standards will be validated using the primary Hg(0) generator from EMRP JRP ENV51 MeTra i.e.: |
VSL, VTT, JSI, Optoseven |
|
A1.3.2 |
Optoseven, with support from VTT, JSI, VSL, PSA and CNR, will validate at least one existing field HgCl2 generator for use at sub ng/m3 levels. This will be undertaken at one of the atmospheric measurement sites selected in Task 4.2 using the transfer gas standard developed in A1.3.1. |
Optoseven, VTT, JSI, VSL, PSA, CNR |
|
A1.3.3 |
Based on the results of A1.3.1 and A1.3.2, JSI, with support from VTT, Optoseven, VSL, PSA and CNR, will produce a method for the on-site traceable generation of HgCl2 at sub-ng/m3 levels, including portable reference gases for atmospheric (oxidised) mercury measurements. |
JSI, VTT, Optoseven, VSL, PSA, CNR |
