Full set of Notes with Fill-Ins - San Jose State University

Chem 155 Unit 1 Page 49 of 3161.1.24 An Example of Standard Additions:1. The analyte sample is split up into e.g. 6 aliquots ofidentical, known volume – e.g. 1.00 ml.2. To each of these, a known quantity of standard(known as a spike) is added – e.g.0, 0.1, 0.2, 0.3, 0.4, 0.5 ml – standard is dissolvedin known matrix like water or 0.1M pH 7 phosphateetc.3. Each aliquot is diluted to a total volume.1. Add sample2. Add standard3. Dilute to volume,and mix mix mix!Note: you split and diluteyour sample – how doesthis impact the precision ofyour measurement?How does this processimpact the accuracy ofyour measurement?Page 49 of 316It decreases it!If volume change is big.It increases it!