Monitoring strategy, technical issues Report from the Oslo workshop and upcoming events Wenche Aas EMEP/CCC

A Gas/Particle distribution Passive samplers, low cost denuder, filterpack, annular denuder, continuous methods Sampling frequency at Level 2 and Level 3 A flexible approach is necessary, and parties may choose between providing campaigns/intensive periods of hourly measurements or longer-term 24 hour Better coordination of the timing of such intensive periods is necessary. Agreement is needed on the timing strategy and the level of ambition Coating material for denuders and filters Methodological artefacts Corrections for imperfect or incomplete sampling QA/QC

B. EC/OC Prefired Quartz fiber filters? Pre-firing should be avoided if possible, as it activates the filters. Mass and the carbonaceous content from the same filters? Preferably not The filter face velocity for sampling of OC? Need to know whether correction for artefacts shall be applied or not. Which instrument should be used? Difference between instruments, temperature programmes, and the monitoring system for charring – transmission or reflectance? TC and Aethalometer, an alternative approach. Is it OK to measure only total carbon ? What about WSOC? Which sampling method should be used to correct for artefacts: QBT: Poor knowledge concerning use in background areas. Denuder-Quartz-fiber filter-sorbent: perhaps a better alternative than QBT. Sampling time: Less than 12 hour to avoid gas/particle problems. But it will affect the mass…

C. Size segregated aerosol chemistry Which PM sizes to priorities? Either PM10 and PM.2.5 or PM10 and PM1 Denuder ? A denuder should be put in front. Commercial denuders not available Filter type discussed (which to chose depends on the use) Mass closures are recommended Major concerns: Conversion factor for OC to OM, missing compounds, water, different sampling times, Dust. Mass and chemical speciation separated? Ideally, yes Continues PM10 monitors Monitors can be accepted in EMEP if proven to be equivalent. Concerns about the quality and the jungle of correction factors that are used. The equivalent tests are often done at higher concentrations than repr for EMEP. On the other hand PM10 mass is not of critical importance for EMEP, and less quality data may be acceptable if flagged properly for studying the temporal resolution

D VOC Which VOC Species to be considered? Which methods? Alkanes C2-C13; Isoprenoids, C2-C4, Alkynes Acetylene Aromates C6-C13 Alcohols C1-C4; Aldehydes C1-C6 Ketones C2-C9 Acetates C3-C6 Halocarbons C1-C2 Which methods? No standard procedures for C7 to C13 is defined yet. Sampling: Specific enrichment techniques. Artefact formation has to be carefully assessed. Analytical Procedure, GC-FID C2-C7 (C7-C14 requires GC-MS) HPLC-DAD, PTR-MS for carbonyls QA/QC Use Audit questionnaire from WMO-GAW Joint GAW/EMEP courses Use DQO and metadata form from GAW

Follow ups Include the clear recommendations and new standard methods in the EMEP manual. Courses and training: 1) Low cost denuder workshop in May 2) VOC (and CO2) workshop in June 3) EMEP CCC. One course annually, each autumn. Next topic is not decided. Suggestions are welcomed Quality assurance e.g. field and lab intercomparison and audits for new sites and methods Further studies necessary for several items. JRC Ispra will do field campaigns on EC/OC 2. Constituents of the organic aerosols Workshop in Oslo 26-27 May