Chemistry 155 Introduction to Instrumental Analytical Chemistry

Chem 155 Unit 1 Page 35 of 3131.10 Experimental Design:Designing an experiment involves planning how youwill: make calibration and validation standards;prepare the sample for analysis; and perform themeasurements.1.10.1 Making a set of calibration standards.1. You need to know the dynamic range of yourinstrument.2. You need to know the sample sizerequirement of your instrument.3. You need to know the estimated expectedconcentration of your sample.4. You need to prepare and dilute your sampleuntil it is a. within the dynamic range of yourinstrument and b. such that there is enoughsolution to measure.5. You need to choose target standardconcentrations that bracket the expectedsample concentration generously – e.g. by afactor of 2 to 3. For example, if your expectedconcentration is 5.3 ppm, you may wish to makea calibration set that consists of standards thatare about 2,4,8,10 and 12 ppm.Page 35 of 313