Chagas Aline Garcia da Rosa, Spinelli Eliani, Fiaux Sorele Batista, Barreto Adriana da Silva, Rodrigues Silvana Vianna
School of Pharmacy, Universidade Federal Fluminense, Rua Mario Viana 523, Niterói, Rio de Janeiro 24241-000, Brazil.
School of Pharmacy, Universidade Federal Fluminense, Rua Mario Viana 523, Niterói, Rio de Janeiro 24241-000, Brazil.
Forensic Sci Int. 2017 Aug;277:188-196. doi: 10.1016/j.forsciint.2017.06.008. Epub 2017 Jun 15.
Different types of hair were submitted to different milling procedures and their resulting powders were analyzed by scanning electron microscopy (SEM) and laser diffraction (LD). SEM results were qualitative whereas LD results were quantitative and accurately characterized the hair powders through their particle size distribution (PSD). Different types of hair were submitted to an optimized milling conditions and their PSD was quite similar. A good correlation was obtained between PSD results and ketamine concentration in a hair sample analyzed by LC-MS/MS. Hair samples were frozen in liquid nitrogen for 5min and pulverized at 25Hz for 10min, resulting in 61% of particles <104μm and 39% from 104 to 1000μm. Doing so, a 359% increment on ketamine concentration was obtained for an authentic sample extracted after pulverization comparing with the same sample cut in 1mm fragments. When milling time was extended to 25min, >90% of particles were <60μm and an additional increment of 52.4% in ketamine content was obtained. PSD is a key feature on analysis of pulverized hair as it can affect the method recovery and reproducibility. In addition, PSD is an important issue on sample retesting and quality control procedures.
将不同类型的毛发进行不同的研磨程序处理，然后通过扫描电子显微镜（SEM）和激光衍射（LD）对所得粉末进行分析。SEM结果为定性结果，而LD结果为定量结果，并通过粒度分布（PSD）准确地表征了毛发粉末。将不同类型的毛发置于优化的研磨条件下，其PSD非常相似。在通过LC-MS/MS分析的毛发样本中，PSD结果与氯胺酮浓度之间存在良好的相关性。将毛发样本在液氮中冷冻5分钟，然后以25Hz的频率粉碎10分钟，结果得到61%的颗粒<104μm，39%的颗粒在104至1000μm之间。这样做的话，与切成1mm片段的同一样本相比，粉碎后提取的真实样本的氯胺酮浓度提高了359%。当研磨时间延长至25分钟时，>90%的颗粒<60μm，氯胺酮含量又增加了52.4%。PSD是粉碎毛发分析中的一个关键特征，因为它会影响方法的回收率和重现性。此外，PSD在样本重新检测和质量控制程序中也是一个重要问题。
