For specified standard(s):
- Precision – Replicate injections (n=6)
- Sensitivity, e.g. by running a standard of concentration close to LOQ
- Retention time.
SST standards are prepared in a solvent suitable for the analysis.
Two separate SST samples may be prepared: one spiked at a higher concentration (e.g. 1ppm) to assess specificity and precision, and one spiked at a concentration close to LOQ to assess sensitivity. Alternatively, additional compound(s) can be spiked at a low concentration to the high-spike SST sample to assess sensitivity. Another option is to use a high-concentration spike SST, e.g. 1ppm, and set a relevant signal-to-noise (S/N) ratio requirement to assess sensitivity.
Retention time can be a good indicator of system performance. No pass criteria are given for retention time. Noting the retention time of the recommended standards also facilitates a comparison between laboratories of chromatographic range