Nitrosamine impurities occur at microgram levels. Hence, sensitive and specific analytical techniques are required for their detection. The amount of impurities detected in drug products can vary widely depending on who performed the test, the drug manufacturer and the specific batch tested. Gas chromatography (GC) coupled with thermal energy analysis or mass spectrometry (MS) can be used to detect heat-sensitive nitrosamine impurities. GC coupled with MS is reported to have high selectivity and sensitivity. Another option is the use of liquid chromatography (LC) coupled with thermal energy analysis, MS or ultraviolet light (UV). LC can be used for both volatile and non-volatile nitrosamines. High-performance liquid chromatography (HPLC) and UV can help analyze low-dose drugs.