Accurate Measurement of Particulate Nitrogen and Phosphorus in - PowerPoint PPT Presentation

Accurate Measurement of Particulate Nitrogen and Phosphorus in Environmental Phosphorus in Environmental Water Samples Carl Zimmermann Carolyn Keefe Carl Zimmermann, Carolyn Keefe and Jerome Frank UMCES, Chesapeake Biological g Laboratory

Outline • Total Versus Particulate and Dissolved • Methods Used Methods Used • Examples of Data Using Direct Measurements – Chesapeake Bay – Near Coastal – Fresh Water Ponds • SRM, Chesapeake Bay Split Sample Program • Chesapeake Bay Blind Audit Program

Components Of A Whole Water S Sample l Whole Water Particulate Sample Sample Dissolved Advantages of Direct Particulate Analysis Advantages of Direct Particulate Analysis 1. A representative sample can always be obtained. 2. Additional Information is Obtained 1. Contribution of biological community 2. How the various fractions may shift spatially and temporally

“By-Difference” vs Direct Analysis of Particulates f P i l B B A A “By Difference”….. Total – Dissolved= Particulate Consequences: Opportunity for negative particulate values. Direct Measurement: Can always obtain a representative sample

Methods Methods • Particulate Nitrogen: EPA Method 440 0 Particulate Nitrogen: EPA Method 440.0… (high temperature combustion, using thermal conductivity detection) Exeter thermal conductivity detection). Exeter Analytical CE440 Elemental Analyzer. • Particulate Phosphorus: Aspila et al 1976 • Particulate Phosphorus: Aspila, et al. 1976 (high temperature ashing/acid extraction)

Examples of Particulate and Di Dissolved Distributions l d Di ib i • Coastal Coastal …. DNR Coastal Survey May DNR Coastal Survey May 2011 • Estuarine • Estuarine… Chesapeake Bay 2001-2003 Chesapeake Bay 2001 2003 • Agricultural Ponds… Calvert County, MD

Total P Near Coastal May 2011 Total P Near Coastal May 2011 Surface Mid Total P Near Coastal May 2011 Surface Total P Near Coastal May 2011 Mid 0.0400 0.0500 0.0450 0.0350 0.0400 0.0300 0.0350 0.0250 0.0300 Dissolved sso ed g P/L g P/L 0.0200 0.0200 0.0250 0.0250 mg mg Dissolved 0.0200 0.0150 0.0150 0.0100 0.0100 Particulate 0.0050 0.0050 Particulate 0.0000 0.0000 1 1 3 3 5 5 7 7 9 9 11 13 15 17 19 21 23 25 27 29 31 11 13 15 17 19 21 23 25 27 29 31 1 1 4 4 7 7 10 10 13 13 16 16 19 19 22 22 25 25 28 28 31 31 34 34 37 37 Stations Stations Total P Near Coastal May 2011 Bottom 0.0600 Bottom Bottom Surface: Particulate: 39% 0.0500 0.0400 Mid: Particulate 37.8% mg P/L 0.0300 Dissolved Bottom (10 m): 37% Bottom (10 m): 37% 0.0200 0 0 00 0.0100 Particulate 0.0000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 Stations

Total N Near Coastal May 2011 Total N Near Coastal May 2011 Surface Mid Total N Near Coastal May 2011 Mid Total N Near Coastal May 2011 Surface 0.5000 0.4500 0.4500 0.4000 0.4000 0.3500 0.3500 0.3000 0.3000 Dissolved L Dissolved L / N 0.2500 N / 0.2500 g m g m m 0 2000 0.2000 0 2000 0.2000 0.1500 0.1500 Particulate 0.1000 0.1000 Particulate 0.0500 0.0500 0.0000 0.0000 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 1 4 7 10 13 16 19 22 25 28 31 34 37 Stations Stations Total N Near Coastal May 2011 Bottom Surface Particulate: 32.9% 0.4500 0.4000 0.3500 Mid Particulate: 32.6% Dissolved Dissolved 0.3000 mg N/L 0.2500 0.2000 Bottom (10 m): 31.1% 0.1500 0.1000 Particulate 0.0500 0.0000 1 1 3 3 5 5 7 7 9 9 11 11 13 13 15 15 17 17 19 19 21 21 23 23 25 25 27 27 29 29 Stations Bottom

Chesapeake Bay 2001-2003 Upper Bay Total N U B T l N Total N CB5.2 2001-2003 Bottom Total N CB5.2 Surface 2001-2003 Surface Bottom 1.2 1.4 1.2 1 1 1 Dissolved Dissolved 0.8 mg N/L 0.8 mg N/L 0.6 0.6 0.4 0.4 0 4 0.2 0 0.2 Particulate Particulate 0 2003 2001 2003 2001 Particulate Fraction Particulate Fraction Mean: 23.3% Mean: 30 1% Mean: 30.1% Range: 10-65% Range: 15-50%

Chesapeake Bay 2001-2003 U Upper Bay Total P B T l P Total P CB5.2 2001-2003 Surface Total P CB5.2 2001-2003 Bottom Bottom o o 0.06 0.14 Surface Surface 0.12 0.05 Dissolved Dissolved 0.1 0.04 0.08 /L L mg P/L mg P/ 0.03 0.06 0.02 0.04 0.01 0 02 0.02 Particulate Particulate 0 2001 2003 0 2001 2003 Particulate Fraction Particulate Fraction Mean: 50% Mean: 39.8% Range: 18-70% Range: 10-90%

Nitrogen Partitioning Fresh Water Pond Nitrogen Partitioning November Nitrogen Partitioning August 1.8% 16% 25.5% 36.2% 36 % 62% 58.5% DIN= Blue DON= Purple Particulate N= Beige Particulate N= Beige

Phosphorus Partitioning Fresh Water Pond Phosphorus Partitioning November Phosphorus Partitioning November Phosphorus Partitioning August Phosphorus Partitioning August 8% 20% 8% 60% 20% 84% 84% DIP= Blue DIP= Blue DOP= Purple Particulate P= Beige

Determining Accuracy and Precision of Di Direct Particulate Measurements t P ti l t M t • Determining Accuracy in the Lab Determining Accuracy in the Lab • Chesapeake Bay Split Sample Program • Chesapeake Bay Blind Audit Program Ch k B Bli d A dit P

No Commercially Available SRM for Particulate N and P BCSS-1 Marine Sediment (Gulf of St. Lawrence) National Research Board of Canada. Historical Value of N: 0.2% Hi t i l V l f N 0 2% R li bl Reliable Value of P: 0.0672% V l f P 0 0672% BCSS-1 Sediment N 2009-2010 BCSS-1 %P 2010 0.25 0.1200 Nitrogen 0.24 Phosphorus 0.23 0.1000 0.22 0 0800 0.0800 0.21 %N 0.20 %P 0.0600 0.19 0.0400 0.18 0.17 0 17 0.0200 0.16 0.15 0.0000 Occurrences Mean= 0 20% Mean= 0.20% Mean= 0 068% Mean= 0.068% Std. Dev.= 0.0057 Std. Dev.: 0.0059 %CV= 2.8 %CV= 8.7

Chesapeake Bay Coordinated Split S Sample Program l P • Quarterly split samples collected Quarterly split samples collected • Delivered to laboratories same day • Samples processed by groups the S l d b th following day • Results indicative of processing and analytical variability

Particulate N and P Mainstem CSSP 2010 CSSP 2010 0 25 0.25 0.025 0.2 0.02 0.15 0.015 0 015 mg N/L L mg P/L 0.1 0.01 0.05 0.005 0 0 Feb. May Aug Nov Feb. Feb. May Aug Nov Feb. Particulate N Particulate P

Chesapeake Bay Blind Audit Program • Particulate and Dissolved Unknowns Sent Particulate and Dissolved Unknowns Sent to Participating Laboratories Semi- annually annually. • Prepared Concentrations Approximate Estuarine Levels Estuarine Levels

Blind Audit Particulates Blind Audit Particulates • Natural Population Samples Collected Natural Population Samples Collected From End of CBL Pier. • Filtered and Dried • Filtered and Dried • Several Replicates Analyzed At CBL To Provide Estimate of Analytical and P id E ti t f A l ti l d Processing Variablility. • Eliminates other laboratories processing variability

Apparent vs Reported Apparent vs Reported Particulate N Blue: Particulate P Multiple Multiple 0.3 0.3 0 035 0.035 Replicates 0.03 0.25 0.025 0.2 mg N/L mg P/L 0.02 Purple: 0.15 0.015 Laboratory Laboratory 0.1 0.01 0 01 0.05 Results 0.005 0 0 1998 2003 2011 1998 2003 2011 Particulate P CBL Labs Particulate N CBL Labs 1998 1998 Mean 0.0318 0.0316 Mean 0.078 0.0733 SD 0.001 0.0005 SD 0.004 0.0087 %CV 3.1 1.6 %CV 5.1 11.9 2003 2003 Mean 0.0159 0.014 Mean 0.26 0.243 SD 0.001 0.0008 SD 0.0048 0.0223 %CV 3.1 1.6 %CV 1.8 9.2 2011 2011 Mean 0.0203 0.0197 Mean 0.23 0.221 SD 0.0018 0.0026 SD 0.0079 0.0131 %CV 8.9 13.2 %CV 3.4 5.9

CBP Blind Audit Summer 2010 S 2010 Summer 2010 Blind Audit Particulate Nitrogen Summer 2010 Blind Audit Particulate Phosphorus 0.5 0.04 0.45 0.035 0.4 0.03 0.35 0.025 0.3 N/L P/L 0 25 0.25 0 02 0.02 mg mg 0.2 0.015 0.15 0.01 0.1 0.005 0.05 0 0 Laboratories Laboratories Laboratories Laboratories Particulate P Particulate N Mean: 0.0298 mg P/L Mean: 0.255 mg N/L Std. Dev.: 0.0036 Std. Dev.: 0.068 %CV: 12.03 %CV: 26.9

CBP Blind Audit Winter 2011 Wi 2011 Winter 2011 Particulate N Winter 2011 Particulate P 0 3 0.3 0 025 0.025 0.25 0.02 0.2 0.015 P/L N/L 0 15 0.15 mg mg 0.01 0.1 0.005 0.05 0 0 0 Particulate N Particulate P Mean: 0.221 mg N/L Mean: 0.0197 Std. Dev.: 0.014 Std. Dev.: 0.0026 %CV: 5 9 %CV: 5.9 %CV: 13 %CV: 13

Conclusions • Direct measurement of particulates Direct measurement of particulates preferred over the “by-difference” technique. q • Particulate analysis gives an estimate of biological fraction g • Cost • Chesapeake Bay Program has programs Chesapeake Bay Program has programs in place to adequately address precision and accuracy of these fractions y