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Table of Contents

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Data reports are not available at the instrument, but data can be viewed by selecting View Datalog (Figure 20) from the Main instrument panel. Also, the software appends the alkalinity results to the DAT file C:\ProgramData\IODP\Alkalinity. The best way to view the alkalinity values is via LIMS Reports. It is also highly recommended to record the alkalinity and pH values in the blue laboratory notebook to protect against inadvertent data loss.



Figure 20. Datalog.



Quality assurance/quality control

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An analytical batch is a group of samples run together in one sequence, sharing a calibration curve, blanks, reference materials, and verification samples. The alkalinity batch size is 10 samples. Each batch of 10 unknown samples contains a sample to verify precision and a sample to verify accuracy.


Blanks

Blanks are not run for this method because DI water has no buffering capacity and would therefore fail the slope program. Thus, blanks are not applicable to this chemistry.

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Alkalinity dataflow


User-defined variables (Figure 13), with values from the example given in the Dispensing rate section:
$MV1: rate 1 mV threshold (150 mV)
$MV2: rate 2 mV threshold (220 mV)
$MV3: rate 3 mV threshold (240 mV)
$Rate1: rate for first mV threshold (15 µl)
$Rate2: rate for second mV threshold (4 µl)
$Rate3: rate for third mV threshold (3 µl)
$SlopeSpan: number of samples used to calculate the slope (default = 30)
$StabilityThreshold: maximum slope value to ensure a stable reading (also referred to as stability criteria)

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When the alkalinity titration finishes, the GRAN-METHOD window shows the slope information, correction factors, and the final alkalinity value (Figure 18).
Edit outlier Gran factor points, if necessary. When satisfied with the results, click Ok/Save to load the values into LIMS.



Health, safety and environment

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