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

Chem 155 Unit 1 Page 47 of 316Standard additions fix matrix effects:Use the method of standard additions when matrixeffects degrade the accuracy of the calibration curves.There is one important assumption built into thecalibration curve idea. That assumption is thefollowing:the sensitivity of the instrument to the analyte in the standards isEQUAL TOthe sensitivity of the instrument to the analyte in the sample matrixWhy would the sensitivity be different?1. Many Instruments are sensitive to things like:1. pH 2. ionic strength 3.organiccomponents of the solvent matrix2. Sometimes other chemicals can change thecalibration sensitivity by:chemically binding to or interacting with theanalyte atom/moleculeThese two things are examples of:Matrix EffectsPage 47 of 316