Objectives: To study the effects of temperature and time for diatoms digestion and find out suitable digestive temperature and time.
Methods: Eighty pieces of liver tissues were collected, each piece of tissue was 2 g, and 2 mL Pearl River water was added to each piece of tissue. The digestion temperature was set at 100 ℃, 120 ℃, 140 ℃, 160 ℃, 180 ℃ and the digestion time was set at 40, 50, 60, 70, 80 min. The liver tissue and water mixture were divided into 8 portions in each group. All the samples were tested by microwave digestive - vacuum filtration - automated scanning electron microscopy method. The quantity of diatom recovered and the quality of residue on the membrane were recorded.
Results: When the digestion time was set to 60 min, there were statistically significant differences in the number of diatoms recovered at different temperatures (P<0.05). The maximum number of diatoms recovered was (28 797.50±6 009.67) at 140 ℃, and the minimum residue was (0.60±0.28) mg at 180 ℃. When the digestion temperature was set at 140 ℃, there were statistically significant differences in the number of diatoms recovered at different digestion times (P<0.05). The number of diatoms recovered was the highest at 40 min, it was up to (20 650.88±1 950.29), and the residue quality of each group had no statistical significance among different digestion time groups(P>0.05).
Conclusions: The effect of diatom digestion is related to temperature and time. When the digestion temperature was 140 ℃ and the digestion time was 40, 50 and 60 min, it is favorable for diatom test.
目的: 探索硅藻检验过程中组织消解温度和消解时间的合理条件。方法: 取肝组织80份，每份2 g，将每份肝组织分别加入2 mL珠江水样混合。设置消解温度为100 ℃、120 ℃、140 ℃、160 ℃、180 ℃和消解时间为40、50、60、70、80 min对所取肝组织和水样混合物进行分组，每组8份。使用微波消解-真空抽滤-扫描电子显微镜法对上述检材进行硅藻检验，检测硅藻回收数量和滤膜上的残留物质量。结果: 消解时间设置为60 min时，不同温度下硅藻的回收数量之间差异有统计学意义（P<0.05），140 ℃时硅藻回收数量最高，可达（28 797.50±6 009.67）个，滤膜上的残留物质量在180 ℃时最低，为（0.60±0.28）mg。消解温度设置为140 ℃时，不同消解时间的硅藻回收数量之间差异具有统计学意义（P<0.05），40 min时硅藻回收数量最高，可达（20 650.88±1 950.29）个，各组滤膜上的残留物质量在不同消解时间组之间差异无统计学意义（P>0.05）。结论: 硅藻消解效果与温度、时间有关，当消解温度为140 ℃，消解时间为40、50、60 min时利于硅藻检出。.
Keywords: diatom test; digestive temperature; digestive time; forensic pathology.