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Concentration page

Plot absorbance versus concentration for solutions. Apply a linear fit to the data to determine the unknown concentration of a solution.

Note

Before analyzing the concentration, you must go to the Analyze Solution page, record a solution run, and specify its analysis wavelength.

  1. y-axis Measurement

    Click the displayed measurement to switch between viewing Absorbance and Transmittance on the y-axis.

  2. Live Scan Display

    The Live Scan Display shows the Absorbance (or Transmittance) versus Wavelength graph for the sample currently being monitored, as well as the wavelength being analyzed. Click to show or hide the display.

  3. Linear Fit tool

    Click to add a best fit line to the data. This will also display the slope (m) and y-intercept (b) of the line. The correlation coefficient (r) indicates how well the line fits the data, with 1.000 being a perfect fit.

  4. Annotation tool

    Click to add a note in the graph. The tool can be attached to a data point by dragging the tool to the point. Click the annotation box to enter text.

  5. Coordinates tool

    Click to add the tool to the graph. Drag the tool to a data point to view the coordinates of that point.

  6. Scale to fit

    Click to automatically scale the axes so that all data is visible in the graph.

    Tip

    You can also scale the graph manually by clicking and dragging the axes or plot area.

  7. Active Solution

    This field displays a list of data runs that were recorded in the Analyze Solution page. Click to select the data run (solution) you want to analyze.

  8. Record

    Click to begin data recording. Click Stop to end data collection and keep the displayed data.

  9. Determine Unknown Concentration table

    Use this table to record the absorbance of a solution of unknown concentration. After fitting a line to the known concentration values, click the Concentration cell to enter a prediction for the unknown concentration. A data point will appear on the graph, with its color indicating how well the prediction correlates with the best fit line:

    • Green : Indicates a good prediction (less than 5% error).

    • Yellow : Indicates a prediction that is close, but should be revised (5–10% error).

    • Red : Indicates that the prediction is far off (more than 10% error).

  10. Enter Concentration Values table

    Use this table to enter the known concentration values of your samples. After clicking Record , select the Absorbance cell for the current solution concentration in the spectrometer, then click Accept to keep the value.

  11. Fluorescence Tabs (Wireless Spectrometer only)

    The Wireless Spectrometer contains a 405 nm and 500 nm LED for use in fluorescence experiments. Use this feature to explore the excitation of substances at two different wavelengths. Click the tab to turn on the LED of the specified wavelength.