Moreno P, Quijano M A, Gutiérrez A M, Pérez-Conde M C, Cámara C
Departamento de Química Analítica, Facultad de C.C. Químicas, Universidad Complutense, Ciudad Universitaria s/n, 28040 Madrid, Spain.
Anal Bioanal Chem. 2002 Oct;374(3):466-76. doi: 10.1007/s00216-002-1497-2. Epub 2002 Sep 14.
To obtain reliable information on speciation analysis it is necessary to previously evaluate the stability of the species in the sample of interest. Furthermore, in those cases in which sample treatment to extract the species is time-consuming, an evaluation of how to maintain species integrity in the extracts is paramount. Thus, the present paper reports the stability of total Se, SeMet and TMSe+ in freeze-dried oyster and in the enzymatic extracts stored in Pyrex and polyethylene containers at different temperatures (-18, 4 and 20 degrees C). Total selenium determinations and Se speciation were carried out by HG-AAS after acid digestion in a microwave oven and by on-line coupling of cation exchange HPLC-ICP-MS after enzymatic hydrolysis, respectively. The results obtained for the freeze-dried sample showed that total Se and the selenium species evaluated are stable for at least 12 months, under all the conditions tested. However, Se species in the enzymatic extracts are only stable for 10 days if stored at 4 degrees C in Pyrex containers. These results show that the extracts do not necessarily have to be analysed just after sample treatment.
为了获得关于形态分析的可靠信息，有必要预先评估目标样品中各物种的稳定性。此外，在那些用于提取物种的样品处理耗时的情况下，评估如何在提取物中保持物种完整性至关重要。因此，本文报道了冻干牡蛎中总硒、硒代蛋氨酸和三甲基硒离子以及在不同温度（-18℃、4℃和20℃）下储存在派热克斯玻璃和聚乙烯容器中的酶提取物的稳定性。分别通过在微波炉中酸消解后用氢化物发生原子吸收光谱法（HG-AAS）测定总硒以及酶水解后通过阳离子交换高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）在线联用进行硒形态分析。冻干样品的结果表明，在所测试的所有条件下，总硒和所评估的硒物种至少在12个月内是稳定的。然而，如果在4℃下储存在派热克斯玻璃容器中，酶提取物中的硒物种仅在10天内稳定。这些结果表明，提取物不一定必须在样品处理后立即进行分析。
