Technical data

192 Understanding Your Agilent ChemStation

8 Automation

Cyclic Calibration Sequences with Bracketing

In a cyclic calibrated sequence with bracketing, the calibration table used to

calculate the unknown quantitative results is generated by averaging the

results of the current calibration with those of the previous calibration. This

new calibration table is a more accurate representation of the instrument

response at the time the sample was analyzed.

Example

Consider the following situation:

• The instrument response is drifting.

• Three injections of an identical two-component mixture are specified.

• Two injections are specified as calibration samples, and one is specified as

a sample.

• The first and third are calibration samples.

• The second injection is a sample.

To obtain a precise quantitative result for injection two (the sample), an

interpolation must be made between the two calibration samples; see the

figure. This process is known as bracketing.