The anesthetic propofol and other exhaled organic compounds can be sampled in Tenax sorbent tubes and analyzed by gas chromatography coupled with mass spectrometry. The aim of this study was to evaluate the stability of propofol in Tenax sorbent tubes during overseas shipping. This is relevant for international pharmacokinetic studies on propofol in exhaled air. Tenax sorbent tube propofol samples with concentrations between 10 and 100 ng were prepared by liquid injection and with a calibration gas generator. For each preparation method, one reference set was analyzed immediately after preparation, a second set was stored at room temperature, and a third one was stored refrigerated. The fourth set was sent from Germany by airmail to USA and back. The shipped set of tubes was analyzed when it returned after 55 days elapsed. Then, the room temperature samples and the refrigerated stored samples were also analyzed. To evaluate the stability of propofol in the stored and shipped tubes, we calculated the recovery rates of each sample set. The mean recovery in the stored samples was 101.2% for the liquid preparation and 134.6% for the gaseous preparation at 4°C. At 22°C, the recovery was 96.1% for liquid preparation and 92.1% for gaseous preparation, whereas the shipped samples had a recovery of 85.3% and 111.3%. Thus, the deviation of the shipped samples is within a range of 15%, which is analytically acceptable. However, the individual values show significantly larger deviations of up to -32.1% (liquid) and 30.9% (gaseous). We conclude that storage of propofol on Tenax tubes at room temperature for 55 days is possible to obtain acceptable results. However, it appears that due to severe temperature and pressure variations air shipment of propofol samples in Tenax tubes without cooling shows severe deviations from the initial concentration. Although it was not tested in this study, we assume that refrigerated transport might be necessary to obtain comparable results as in the stored samples.

中文翻译：

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空气运输过程中热解吸管中丙泊酚（2,6-二异丙基苯酚）的稳定性。

麻醉的异丙酚和其他呼出的有机化合物可在Tenax吸附管中取样，并通过气相色谱法和质谱法进行分析。这项研究的目的是评估在海外运输期间Tenax吸附剂管中丙泊酚的稳定性。这与呼出气中异丙酚的国际药代动力学研究有关。通过液体注入和校准气体发生器制备浓度为10到100 ng的Tenax吸附剂异丙酚样品。对于每种制备方法，在制备后立即分析一个参考组，将第二组在室温下保存，将第三组冷藏保存。第四套是通过空邮从德国寄回美国的。经过55天后返回时，对出厂的那组试管进行了分析。然后，还分析了室温样品和冷藏样品。为了评估丙泊酚在储存和运输的试管中的稳定性，我们计算了每个样品组的回收率。在4°C下，液体样品的平均回收率为101.2％，气体样品的平均回收率为134.6％。在22°C下，液体制备的回收率为96.1％，气体制备的回收率为92.1％，而运送的样品的回收率为85.3％和111.3％。因此，运送的样品的偏差在15％的范围内，这在分析上是可接受的。但是，各个值显示出明显更大的偏差，高达-32.1％（液体）和30.9％（气体）。我们得出的结论是，将异丙酚在Tenax管上于室温下存放55天是可能的，以获得可接受的结果。然而，似乎由于温度和压力的剧烈变化，未经冷却的Tenax管中的异丙酚样品的空气运输显示出与初始浓度的严重偏差。尽管未在本研究中进行测试，但我们认为冷藏运输可能是必要的，以获得与储存样品相当的结果。