Table 1. General QA/QC information for constituents used in K. McGuire's Project Constituent Units Detection Limit Quantitation Limit *Mean_difference_Dups Stdev_difference_Dups Mean%_difference_Dups N_duplicates Mean_blank value Stdev_blank value N_blanks Comments Na microeq/L 0.5 2 1.75 2.06 0.3 12 4.75 1.73 7 NH4 microeq/L 0.9 8 ND ND ND 12 ND ND 7 K microeq/L 0.2 1 0.36 0.68 2.5 12 ND ND 7 Mg microeq/L 1.0 2 1.34 1.89 0.4 12 0.54 1.27 7 Ca microeq/L 0.6 2 8.46 8.92 0.9 12 12.43 11.65 7 Cl microeq/L 0.8 2.8 3.21 2.34 2.3 12 3.94 0.94 7 NO3 microeq/L 0.2 1.6 0.1 0.31 20 5 ND ND 7 Nitrate not NO3-N; blanks had reported values of both <0.2 & <1.6; one blank % difference was 96.5% (1.12 & 0.02) SO4 microeq/L 0.6 2.1 1.74 3.97 2.4 12 0.74 1.49 7 Si micromol/L 3.3 NA 31.4 61.6 8.4 13 ND ND 11 d18O per mil 0.01 NA NA NA NA Br microeq/L **AGA micro_g/L 1.0 NA 0.15 0.27 0.3 10 0.15 0.04 20 "*Dups are lab duplicates for all constituents except d18O, which were blind duplicates; ND=non detectable; NA= not applicable" "**AGA concentrations are given prior to background correction (e.g., flow dependent correction)" Table 2. Lab time table CCAL CCAL USGS USGS USFS Boise USFS Boise SAMP_ID SITE CollectionTime CCAL_ID StorageTime AnalysisTime StorageTime AnalysisTime StorageTime AnalysisTime 1414 WS02 11/11/02 20:00 385 ~220 d 7/30/2003 ~48 d 2/6/2003 ~120 d 4/15/2003 1425 WS02 11/13/02 5:00 386 ~220 d 7/30/2003 ~48 d 2/6/2003 ~120 d 4/15/2003 1454 WS09 11/10/02 17:00 387 ~220 d 7/30/2003 ~48 d 2/6/2003 ~120 d 4/15/2003 1485 S1 11/8/02 17:00 389 ~220 d 7/30/2003 ~48 d 2/6/2003 ~120 d 4/15/2003 1512 S1 11/12/02 5:00 390 ~220 d 7/30/2003 ~48 d 2/6/2003 ~120 d 4/15/2003 Table 3. Comparison of major ion analysis between CCAL (OSU/USFS Cooperative Chemical Analytical Lab) and USGS NWQL Denver Na (micro eq/L) USGS CCAL Diff Ratio 1414 126 124 2.61 1.02 1425 132 129 3.04 1.02 1454 115 109 6.09 1.06 1485 565 629 -63.9 0.90 1512 408 425 -17.4 0.96 -13.9 0.99 = mean 29.5 0.06 = stdev NH4 (micro eq/L) USGS *CCAL Diff Ratio 1414 < 0.9 < 1.1 -- -- 1425 < 0.9 < 1.1 -- -- 1454 < 0.9 < 1.1 -- -- 1485 < 0.9 < 1.1 -- -- 1512 < 0.9 < 1.1 -- -- = mean K (micro eq/L) = stdev USGS CCAL Diff Ratio 1414 10.6 11.5 -0.921 0.92 1425 10.8 11.8 -0.972 0.92 1454 3.6 4.9 -1.28 0.74 1485 11.1 11.8 -0.665 0.94 1512 5.5 6.9 -1.41 0.80 -1.0 0.86 = mean 0.30 0.09 = stdev Mg (micro eq/L) USGS CCAL Diff Ratio 1414 75.7 74.6 1.15 1.02 1425 79.4 80.5 -1.07 0.99 1454 99.2 93.4 5.76 1.06 1485 327 356 -29.2 0.92 1512 198 207 -9.38 0.95 -6.6 0.99 = mean 13.8 0.06 = stdev Ca (micro eq/L) USGS CCAL Diff Ratio 1414 203 197 6.47 1.03 1425 214 200 14.0 1.07 1454 227 212 15.2 1.07 1485 1152 1270 -118 0.91 1512 734 762 -28.0 0.96 -22.0 1.01 = mean 56.2 0.07 = stdev Cl (micro eq/L) USGS CCAL Diff Ratio 1414 29.3 1425 29.1 1454 72.8 1485 1433 1512 841 = mean = stdev NO3 (micro eq/L) USGS *CCAL Diff Ratio 1414 < 0.2 < 1.1 -- -- 1425 < 0.2 < 1.1 -- -- 1454 < 0.2 < 1.1 -- -- 1485 < 0.2 < 1.1 -- -- 1512 < 0.2 < 1.1 -- -- = mean = stdev SO4 (micro eq/L) USGS CCAL Diff Ratio 1414 0.76 1425 0.78 1454 2.56 1485 6.13 1512 3.66 = mean = stdev "*CCAL reported total inorganic N (NO2-N + NO3-N), whereas USGS reported nitrate" Table 4. Comparison of Silica analysis between CCAL (OSU/USFS Cooperative Chemical Analytical Lab) and USFS Boise Silica (micro mol/L) Boise CCAL Diff Ratio 1414 396 253 143.13 1.57 1425 398 252 146.0 1.58 1454 -- 223 -- -- 1485 292 240 52 1.22 1512 276 213 63.0 1.30 101.1 1.41 = mean 50.4 0.18 = stdev CCAL CCAL *A *NA Boise Diff Ratio 1414 253 -- 396 -- -- 1425 252 -- 398 -- -- 1454 223 262 -- -- -- 1485 240 272 292 20 1.07 1512 213 252 276 24 1.09 22.0 1.08 = mean 2.7 0.01 = stdev *A = acidified 2% by volume with Ultrex II HNO3 and non-acidified NOTES: (more coming soon!!!) "USGS Denver Lab 2/6/03: I did not include any QA because its specific to each run and takes some work to compile it. Usually, all that anyone asks for is detection limits. I report both a detection limit and a quantitation limit. The det lim is defined as signal discernable from noise but not quantifiable. In other words, there is something there but I don't know how much. Quantitation limit is the lowest quantifiable amount based on a standard 5 times the detection limit that is run multiple times and run through a statisitical calculation. " "USGS Denver lab 2/7/03: More on the DL and QL I went back to look at my QA notes and I mis-lead you. What I told you was the way we did it years ago. Now we do it this way: We run STD 2 of 7 calibration stds n times (30 or more) If the mean of STD2 is within 20% of expected value, then this is the quantitation limit. (it was for all analytes except NH4, hence the higher QL) Then we find the T-value for n multiplied by the std dev and get the detection limit. As I said before, there are a 100 ways to skin a chicken. We prefer this one. The ref is Probablity and Statistics for engineers and scientists, Walpole and Myers, 1885." "Data quality memo from CCAL 8/13/2003: As requested by K. McGuire, dissolved silica analyses were performed using acidified samples. This is a non-standard practice for this laboratory. Standards used to prepare the calibration curve were not acidified. This could lead to results that do not represent actual sample site concentrations for dissolved silica. As a comparison, unacidified samples were also analyzed for dissolved silica for sample numbers 387 - 390. Significantly different results were obtained for the nonacidified samples. Those results are as follows: 387 - 7.35 ppm; 388 - 8.57 ppm; 389 - 7.63 ppm; 390 - 7.08 ppm. Comparing results between acidified and nonacidified samples shows that the acidified results are approximately 85% of the nonacidified results. Please examine the dissolved silica results carefully and take the difference between acidified and nonacidified samples into account when interpreting these data." "Explanation of Silica differences - K. McGuire 8/14/2003: All results are reported as micro mol/L Si and all samples were acidified after filtering with 0.45-micron filters. The acid was 2% by volume (~60 microL) of Ultrex II HNO3 (recommended by USGS NWQL for purity). The acid was stored in a Teflon bottle as to reduce silica disassociation from glass bottles. This preservation method was recommended by people in USGS NASQAN program and is a standard procedure for several of the USGS WEBB research catchments. However, Standard Methods for the Examination of Water and Wastewater (20th ed) states that acidified water samples may cause precipitation of silica. Thus, the differences in holding times between CCAL (~220 days) and USFS Boise (~120 days) may explain higher concentrations of dissolved silica because less time in acidic solution might suggest less silica precipitation and higher dissolved concentrations. This reasoning is support by the re-analysis of the CCAL samples that were not acidified. The non-acidified samples had significantly higher concentrations (between 13 and 18%) than the acidified samples. However, the non-acidified sample results were still lower than the results from USFS Boise. None of the silica samples were frozen at any time; thus, lower silica solubility from that practice can be ruled out." "Last updated by K. McGuire on Aug 14, 2003"