甲醇中29种VOCs混合标准样品短期稳定性研究

为考察运输过程中环境温度的变化对挥发性有机物（VOCs）混合标准样品量值产生的影响，模拟极端运输条件(-40 ℃、4 ℃、室温、55 ℃)，采用经典和同步两种稳定性研究方案考察甲醇中29种VOCs混合标准样品的短期稳定性。结果表明：同步稳定性研究方案因一次校准进行所有测量降低了不确定度，更适合对多组分挥发性有机物进行稳定性评价；在-40 ℃下所研究标准样品所有组分量值稳定， 4 ℃与室温冷藏保存两周期间，标准样品量值稳定，而在55 ℃保存条件下，组分环氧氯丙烷的浓度有明显下降趋势；由于环氧氯丙烷的浓度受温度影响较大，甲醇中29种VOCs混合标准样品在运输过程中需采用低温条件，若长期保存，应尽快转移至冷冻环境中防止环氧氯丙烷分解。

Short-term stability study of 29 kinds of volatile organic compounds in methanol reference material

In order to study the behavior of the volatile organic compounds (VOCs) mixed reference material (RM) during transport, this paper reports the results of simulations under extreme conditions (-40 ℃, 55 ℃, room temperature and 4 ℃）to evaluate the short-term stability of the RM with two stability layouts. The results showed that the isochronous stability study with one calibration was more suitable for VOCs than the classical method. The study also found at 55 ℃ only the value for epichlorohydrin decreased with increasing storage temperature, while all the 29 VOC constituents were stable under other storage conditions. In conclusion, combined with the results of a long-term stability study, the 29 kinds of VOC reference materials should be transported at low temperature and stored at -18 ℃ as soon as possible in order to minimize degradation of epichlorohydrin.