Analysis of Impurities in Tests for Residual Solvents in Pharmaceuticals Using GC-MS

The HS-GC-FID method is adopted for tests of residual solvents in pharmaceuticals, but GC-MS is effective for confirming any unknown peaks (impurities) detected in such tests.
United States Pharmacopoeia (USP) 467 is well known as a test method for residual solvents in pharmaceuticals. In this method, analysis is performed using analysis columns with an internal diameter of 0.32 mm or 0.53 mm, and a length of 30 m, at a linear velocity of 35 cm/s. When GC-MS is used to confirm unknown peaks in chromatograms obtained by GC-FID analysis using large bore columns, approximating the retention times in both chromatograms is essential. If the linear velocity is set at 35 cm/s with GC-MS, the retention times are roughly approximated. However, using such large bore columns and a linear velocity of 35 cm/s in GC-MS will prevent analysis under the designated USP conditions for several reasons. For example, the flowrate will be large, which will have an impact on sensitivity, and the inlet pressure will exceed the control range (decompression region) due to the vacuum in the MS section.
With its differential vacuum system, the GCMS-QP2010 Ultra features high vacuum efficiency, enabling analysis using the same 0.53 mm analysis columns as in GC-FID. The linear velocity of 35 cm/s designated in USP 467 can be achieved by connecting the optimal resistance tube to the column outlet.
This Data Sheet presents an example of the analysis of unknown peaks in a test for residual solvents in pharmaceuticals, using analysis columns that complies with USP467 Procedure A for residual solvents, utilizing the Shimadzu HS-20 Trap headspace sampler, which features a trapping function, and the GCMS-QP2010 Ultra.