Aboulfadl Khadija, De Potter Cyril, Prévost Michèle, Sauvé Sébastien
Département de chimie, Université de Montréal, Montréal, QC, Canada.
Chem Cent J. 2010 Apr 19;4:10. doi: 10.1186/1752-153X-4-10.
Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids, and selected pesticides under refrigerated storage conditions. The analysis was performed using multi-residue methods using an on-line solid-phase extraction combined with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) in the selected reaction monitoring mode. After 21 days of storage, no significant difference in the recoveries was observed compared to day 0 for pharmaceutical products, while for pesticides, significant losses occurred for DIA and simazine after 10 days (14% and 17% reduction respectively) and a statistically significant decrease in the recovery was noted for cyanazine (78% disappearance). However, the estrogen and progestogen steroids were unstable during storage. The disappearance rates obtained after 21 days of storage vary from 63 to 72% for the feminizing hormones. Overall, pharmaceuticals and pesticides seem to be stable for refrigerated storage for up to about 10 days (except cyanazine) and steroidal hormones can be quite sensitive to degradation and should not be stored for more than a few days.
对痕量污染物（如药品和农药）进行监测和分析，需要在使用适当的分析方法进行定量之前对样品进行保存。我们的目标是确定样品的保质期，以确保对超痕量污染物进行准确的定量。为此，我们测试了包括咖啡因、天然甾体激素以及选定农药在内的多种药品在冷藏条件下的稳定性。分析采用多残留方法，在选定反应监测模式下，使用在线固相萃取结合液相色谱串联质谱法（SPE-LC-MS/MS）进行。储存21天后，与第0天相比，药品的回收率未观察到显著差异，而对于农药，地乐酚和西玛津在储存10天后出现显著损失（分别降低14%和17%），且嗪草酮的回收率出现统计学上的显著下降（消失78%）。然而，雌激素和孕激素甾体激素在储存期间不稳定。储存21天后，雌性激素的消失率在63%至72%之间。总体而言，药品和农药在冷藏条件下似乎可稳定保存约10天（除嗪草酮外），甾体激素对降解可能相当敏感，不应储存超过几天。
