1. R&P 8400S and 8400N Ambient Particulate Sulfate and Nitrate Monitors: Performance during PMTACS-NY Intensive Field Campaigns and Routine Measurements (Poster Summary) Prepared for EMEP Workshop on Particulate Matter Measurement & Modeling April 20-23, 2004, New Orleans, LA Olga Hogrefe 1, Oliver V. Rattigan, James J. Schwab 1, Frank Drewnick 1, Kevin Rhoads 1,3, Kenneth L. Demerjian 1 1 -Atmospheric Sciences Research Center, U-Albany, Albany, NY; 2 - Division of Air Resources, New York State Department of Environmental Conservation, Albany, NY; 3 – Siena College, Loudonville, NY

2. Poster Overview Introduction: PMTACS-NY intensive sampling campaigns and NYSDEC routine SO 4 and NO 3 measurements; R&P 8400N/8400S design, main features and operational problems; 8400S (SO 4 ) and 8400N (NO 3 ) measurements results: time series, diurnal patterns, monthly variations of mass concentrations, comparisons with 24-hr filters and other semi-continuous instruments, measuring SO 4 and NO 3 Summary and acknowledgements

3. 8400S and 8400N Operational Problems Short (few days) lifetime NiChrome flash strips; Decreasing efficiency of molybdenum converter of 8400N NOx analyzer. Non-linear aqueous calibration at higher injected amounts of SO 4 (>180 ng) and NO 3 (>60 ng). Ambient T/RH probe sometimes fails (especially in rainy weather). Short (1-2 weeks) life time of Platinum flash strips High (>0.5 mg/m 3 ) and irregular dynamic blanks – QC2004 High cost of some spare parts and consumables Most problems associated with 8400N/8400S operation were or can be resolved.

4. Mass Concentration Time Series (Intensive Studies)

5. Mass Concentration Variations (Routine Measurements) Average Diurnal Patterns (IS52, Bronx, NY) Monthly Variations of SO 4 and NO 3 Mass Concentrations IS52, Bronx WfM

6. Comparisons with Other Semi-Continuous Instruments and 24-hr Filters Recovery – linear regression slope with intercept set to 0; Instruments used for comparisons: Aerosol Mass Spectrometer (AMS), Particle-Into-Liquid-Sampler with Ion Chromatographs (PILS-IC), 24-hr TEOM ACCU filters and 24-hr STN filters. 8400S measurements agree with AMS, PILS-IC and filter- based measurements within 12% or less. Discrepancy between 8400N and AMS/PILS-IC is 10-40%. Compared to filters, 8400N under-measures nitrate by 30- 40%.

7. Questions What have we (can we) learned about the PM problems from continuous measurements? What are the advantages of continuous measurements? Should continuous measurements replace time- integrated measurements; if so, over what timescale? Are continuous measurements ready for prime time? How is confidence in the values created in lieu of standards?