Analytical Chem istry - DePauw University

DRAFTChapter 5Standardizing AnalyticalChapter OverviewMethods5A Analytical Standards5B Calibrating the Signal (S total )5C Determining the Sensitivity (k A )5D Linear Regression and Calibration Curves5E Compensating for the Reagent Blank (S reag )5F Using Excel and R for a Regression Analysis5G Key Terms5H Chapter Summary5I Problems5J Solutions to Practice ExercisesThe American Chemical Society’s Committee on Environmental Improvement definesstandardization as the process of determining the relationship between the signal and theamount of analyte in a sample. 1 In Chapter 3 we defined this relationship asS = k n + S or S = k C + Stotal A A reag total A A r eagwhere S total is the signal, n A is the moles of analyte, C A is the analyte’s concentration, k A is themethod’s sensitivity for the analyte, and S reag is the contribution to S total from sources otherthan the sample. To standardize a method we must determine values for k A and S reag . Strategiesfor accomplishing this are the subject of this chapter.1 ACS Committee on Environmental Improvement “Guidelines for Data Acquisition and Data Quality Evaluation inEnvironmental Chemistry,” Anal. Chem. 1980, 52, 2242–2249.Copyright: David Harvey, 2009153