Abstract
The applicability of liquid chromatography‐atmospheric‐pressure chemical‐ionization‐mass spectrometry (LC‐APCI‐MS) for the determination of 13C‐urea in 13C‐urea/PEG capsules has been studied. It is essential to assess the stability of a newly developed low‐dose (38 mg) 13C‐urea/PEG capsule, which will be used for a 13C‐urea breath test (13C‐UBT) to detect Helicobacter pylori infection. A standard curve was linear over the concentration range 10–1000 µg/mL. Intra‐ and inter‐day variations were less than 2.75% in APCI‐MS. The detection limit was 10 pg when selected ion monitoring (SIM) was employed. The content of 13C‐urea in capsules was within the acceptable range between 95 and 105%. Therefore, it was established that 13C‐urea/PEG capsules were stable under an accelerated stability condition that was set at 40 ± 2°C with relative humidity of 75 ± 5%, during six months by using LC‐APCI‐MS. This research is the first report that describes LC‐APCI‐MS analysis of 13C‐urea capsules.
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Acknowledgments
Authors thank the Human Life Sciences of Brain Korea 21 and Research Institute of Pharmaceutical Sciences at College of Pharmacy in Seoul National University (Republic of Korea) for their financial support.