| Zugriffsnummer | 27601 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Standard addition challenge |
| Autor(in); Institution |
Rienitz, Olaf; 3.1, Metrologie in der Chemie, PTB-Braunschweig
Hauswaldt, Anna-Lisa; 3.1, Metrologie in der Chemie, PTB-Braunschweig
Jährling, Reinhard; 3.1, Metrologie in der Chemie, PTB-Braunschweig
|
| Quelle/Jahr | Analytical and Bioanalytical Chemistry: 403 (2012), 9, 2461 - 2462 |
| ISSN | 1618-2642 (PRINT) ; 1618-2650 (ONLINE) |
| DOI | |
| Verlag | Berlin [u.a.]: Springer |
| Zusammenfassung | Obtaining accurate analyte content when working with a complex sample matrix is always challenging, because of the possibility of different sensitivities of the analyte in sample and standard. If matrix-matched standards are not available or are difficult to prepare, one can always resort to the method of external calibration, however the quality of the results may often be poor. The method of standard addition can overcome the shortcomings commonly associated with external calibration, because it effectively establishes the calibration within the sample analyzed. First described in 1937, the method of standard addition is now an integral part of the analytical chemistry curriculum. The basic concept is always the same. Step 1 place equal volumes of sample into, for example, five volumetric flasks of equal volume. Step 2 add increasing volumes of standard solution to all the flasks but one. Step 3 dilute the contents of each flask to the same volume and calculate the concentration of the added standard. Step 4 measure the analytical signal from each flask. Step 5 plot the regression between the measured signal in step 4 (y-axis) and the calculated concentration of the added standard (x-axis). The extrapolated x-intercept of the linear regression obtained yields the fraction of the analyte concentration in the diluted solutions (step 3) arising from the sample (step 1). Step 6 apply the dilution factor (volume of the flask divided by the volume of the sample from step 1) to obtain the concentration of the analyte in the original sample. |
