# Presentation: 799559

## Determination of base cations usingIon Chromatography

- We analyzed water samples for cations using IC and compared those results to ICP results to validate the decision to change analysis methods.
- We analyzed samples with low organic concentrations and samples with high organic concentrations (labeled Low and High DOC).
- We also analyzed the same samples twice on the IC to indicate result reproducibility, with different operators and calibrations.
- The black line on each graph is the 1:1 line.  The colored line, equation, and r2 value are the regression for low and high DOC samples combined

## Determination of base cations usingIon Chromatography

- Each analyte has two slides associated with it:
- Slide one:
- The left graph represents the average of the results of the two IC runs compared to the ICP results in *μeq/L*.
- The right graph represents the results of the two IC runs compared to each other in *μeq/L*.
- Slide two:
- The left graph represents the comparison of average IC results to ICP results in *mg/L*.
- The right graph represents the comparison of AA results to ICP results in *mg/L*.
- Notice that both the IC and AA results are higher than the ICP.

## Samples Analyzed

| Tunk-o | 18-Nov |
| --- | --- |
| Anderson In 1 | 18-Nov |
| Anderson In 2 | 18-Nov |
| Anderson-E | 18-Nov |

| CB1 | 16-Nov |
| --- | --- |
| HB1 | 16-Nov |
| IH1 | 13-Nov |
| IH2 | 13-Nov |
| IH6 | 14-Nov |
| IH12 | 15-Nov |
| CB1 | 10-Nov |
| HB1 | 10-Nov |

| EB8 | 18-Nov |
| --- | --- |
| WB3 | 18-Nov |
| IE1 | 13-Nov |
| IE3  | 13-Nov |
| IW1 | 13-Nov |
| EB8 | 11-Nov |
| WB3 | 11-Nov |
| EB8  | 4-Nov |
| WB3 | 4-Nov |
| IE1 | 29-Oct |
| IE5 | 29-Oct |
| IE6 | 30-Oct |
| IE10 | 30-Oct |
| IWB1 | 29-Oct |
| IWB3 | 29-Oct |
| IWB5 | 30-Oct |
| IWB9 | 30-Oct |

- BBWM

- Acadia

- RLTM

| Newbert-E Dup | 28-Jul |
| --- | --- |
| Newbert-O | 27-Apr |
| Abol-O    | 29-Apr |
| Abol-E   | 12-Aug |
| Baker | 3-Jun |
| Round-E Dup | 22-Jul |
| Rocks HELM | 14-Oct |
| Partridge-H    | 11-Aug |
| Upper Sister Lake  | 19-Aug |
| Penobscot  | 28-Oct |
| Hodge Pond TIME | 27-Aug |
| Wiley-E RLTM   | 20-Oct |

_**Low DOC**_

_**High DOC**_

- All samples takes in 2003; N=41

## Calcium analysisComparison to ICP and IC reproducibility

## Calcium analysisIC to ICP comparison vs AA to ICP comparison

## Magnesium analysisComparison to ICP and IC reproducibility

## Magnesium analysisIC to ICP comparison vs AA to ICP comparison

## Sodium analysisComparison to ICP and IC reproducibility

## Sodium analysisIC to ICP comparison vs AA to ICP comparison

## Potassium analysisComparison to ICP and IC reproducibility

## Potassium analysisIC to ICP comparison vs AA to ICP comparison

## Summary Statements

- Analyses were biased high towards IC for all comparisons
- Analyses were also biased high towards AA for all ICP vs AA comparisons except Na
- When data were analyzed separately, IC analyses differed from ICP analyses less among low DOC samples.
- NH4 analysis is not running well yet.  NH4 may degrade too quickly because we do not acidify samples.

|                      Table of r2 values for comparisons |  |  |  |  |
| --- | --- | --- | --- | --- |
|  | Ca | Mg | Na | K |
| IC Precision | 0.999 | 0.998 | 0.998 | 0.999 |
| IC vs ICP correlation (bias towards)
 | 0.980
(IC) | 0.981
(IC) | 0.990
(IC) | 0.972
(IC) |
| AA vs ICP correlation (bias towards)
 | 0.987
(AA) | 0.952
(AA) | 0.986
(none) | 0.988
(AA) |

## Thanks to everyone for their help

Tanya – analysis, data management, and sample prep
Catherine – analysis and sample prep
Lisa – sample prep and IC setup
Ken – analysis, data management, and sample prep
SK – ideas, consulting, equipment procurement

- Tanya – analysis, data management, and sample prep
- Catherine – analysis and sample prep
- Lisa – sample prep and IC setup
- Ken – analysis, data management, and sample prep
- SK – ideas, consulting, equipment procurement