https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.1002/sscp.70300
ABSTRACT
The assessment of nitrosamine risk in pharmaceuticals is an issue for ensuring the safety and efficacy of medicinal products. In this study, we report a widely accessible derivatization-free high-performance liquid chromatography with ultraviolet detection (HPLC–UV) workflow that enables nitrite quantification in pharmaceutical excipients with strong matrix effects, thereby supporting risk assessment and quality control. We developed an improved preprocessing extraction procedure and applied the method to two frequently used color additives, namely, Sunset Yellow FCF and Sunset Yellow FCF aluminum lake, as well as five different grade microcrystalline celluloses. To position the workflow within existing options, ion chromatography with conductivity detection (IC–CD) was also examined as a reference platform. For HPLC–UV, no interfering peaks were observed at the nitrite retention time in the test matrix blanks; calibration correlation coefficients were >0.9999, and repeatability was 0.8%–3.1% relative standard deviation (RSD). It achieved a solution limit of quantitation (LOQ) of 10 ng/mL for the color additives, and nitrite recoveries from spiked sample solutions were 96.9% for Sunset Yellow FCF and 105.2% for Sunset Yellow FCF aluminum lake (25 ng/mL). The key methodological advance is that this HPLC–UV workflow enables nitrite determination without derivatization and without removing the organic color matrix, thereby avoiding pretreatment conditions that can promote nitrite loss. When applied to microcrystalline cellulose extracts prepared at 100 mg/mL, the method provided an LOQ of 2 ng/mL, corresponding to 20 ng/g in the solid material; all grades purchased from a single vendor were below this level. Among the color additives, nitrite was below the LOQ in Sunset Yellow FCF, whereas one Sunset Yellow FCF aluminum lake product showed an elevated level of approximately 88 µg/g. Overall, the proposed HPLC–UV strategy achieved the states LOQs and recoveries using standard instrumentation and may support quality control and nitrosamine risk assessment in excipients with strong matrix effects.