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Thanks @mflorea !! Open access…
Great summary on the overview of methods used by the consortium to determine nitrite in excipients.
| Analytical Technique | Median Nitrite LOQ (µg/g) | Min Nitrite LOQ (µg/g) | Max Nitrite LOQ (µg/g) | Number of Records | % Number of Records |
|---|---|---|---|---|---|
| Direct Methods | |||||
| IC – CD or UV | 0.181 | 0.01 | 5 | 1130 | 45.3 |
| LC – UV | 0.18 | 0.008 | 0.8 | 139 | 5.6 |
| UV/VIS | 0.125 | 0.05 | 40 | 77 | 3.1 |
| Indirect Methods | |||||
| Griess derivatisation HPLC-UV | 0.1 | 0.03 | 5 | 370 | 14.9 |
| DAN derivatisation HPLC-FL, UV or MS | 0.05 | 0.005 | 1 | 330 | 13.3 |
| Cyclamate derivatisation GC-FID or MS | 0.05 | 0.001 | 0.25 | 61 | 2.4 |
| IC – post column Griess derivatisation UV | 0.015 | 0.01 | 0.1 | 375 | 15.1 |
| Griess derivatisation LC-MS/MS | 0.092 | 0.01 | 0.1 | 8 | 0.3 |
Thanks for sharing, @mflorea. Table 2 is also interesting. It is possible to select the optimal method depending on the target excipient and the equipment available.
Table 2. Summary of analytical techniques and their current advantages and limitations, median LOQ derivative from the Lhasa Nitrites database (2025.1.0) and instrument prevalence.
