Weighing the Analytical Standard

However, in many cases the analyst is faced with the task of quantitative analysis for an analyte for which a certified calibration solution is not available, or is too expensive and thus inappropriate for the stated purpose for which the analysis is to be conducted. In such cases it is necessary to prepare the calibration solutions from scratch from an analytical standard. Precautions in weighing the analytical standard are discussed in Section 2.3.3, and preparation of stock and spiking solutions in Section 9.5.4. 

Stock and spiking solutions (see below) are eventually used to make the cahbration solutions and matrix matched calibrators that are the basis for the comparative measurement of analyte concentration in the unknown analytical sample (Sections 2.6 and 8.5), so the reliability of their concentrations is directly related to that of the measured concentrations. Accordingly, meticulous care and monitoring of these primary solutions is every bit as important as that expended in weighing the analytical standard in the first place (Sections 2.3). 

---