Development of an Aseptic Urine Collection Kit and its Evaluation in Preventing the Bacterial Decomposition of Nitrazepam

A novel aseptic urine collection kit has been devised, and its effectiveness in collecting and storing bacteria-free urine specimens was evaluated. The kit, which is based on filtration sterilization, was proven effective for these purposes. For the evaluation of its efficiency, urine samples spiked with nitrazepam at 0.5 μg/ml were treated with the kit and monitored for 6 months at 4℃ and 25℃. An automated column-switching liquid chromatography-mass spectrometry (LC-MS) procedure was utilized for the direct determination of the analyte in urine. In severely-contaminated urine with bacteria, there were significant losses of nitrazepam at 25℃. However, such degradation was successfully suppressed by the use of the kit even at a storage temperature of 25℃, while requiring no chemical additives.