Metrohm 746 VA Trace Analyzer - Manual (Page 561)

7 Safety, Errors, Troubleshooting, Diagnosis, GLP
746 VA Trace Analyzer / 747 VA Stand
7-62
7.7.5 Assessment of the determination
To assess the recorded lead determination, the results printed out in the full report
for the mass concentration of lead Mass conc. and its total scatter MC.dev. are
used (example, see section 4.2). The limit values of these two results depend
greatly on the care taken in the preparation of the analysis solution and in the dis-
pensing of the standard addition solutions.
When the procedure is carried out properly and carefully, the following results
should be expected:
Accuracy = 95 … … 105 % :
Mass conc. = 0.95 … … 1.05 g/L
Scatter ≤≤ ±± 3 % : MC.dev. ≤≤ ±± 0.03 g/L (±± 3 %)
The reproducibility can be determined by performing the Testpb method several
times and comparing the results obtained for the mass concentration Mass conc. .