Marcó P Lué M, Hernández Caraballo Edwin A, Pascusso Carmine, Alvarado José
Laboratorio de Espectroscopía Atómica, Departamento de Química, Universidad Simón Bolívar, Caracas, Venezuela.
Talanta. 2003 Apr 10;59(5):897-904. doi: 10.1016/S0039-9140(02)00652-5.
A simple procedure for the determination of manganese in different sections of human brain samples by graphite furnace atomic absorption spectrometry has been developed. Brain sections included cerebellum, hypothalamus, frontal cortex, vermix and encephalic trunk. Two sample preparation procedures were evaluated, namely, slurry sampling and microwave-assisted acid digestion. Brain slurries (2% w/v) could be prepared in distilled, de-ionized water, with good stability for up to 30 min. Brain samples were also digested in a domestic microwave oven using 5 ml of concentrated HNO(3). A mixed palladium+magnesium nitrate chemical modifier was used for thermal stabilization of the analyte in the electrothermal atomizer up to pyrolysis temperatures of 1300 degrees C, irrespective of the matrix. Quantitation of manganese was conducted in both cases by means of aqueous standards calibration. The detection limits were 0.3 and 0.4 ng ml(-1) for the slurry and the digested samples, respectively. The accuracy of the procedure was checked by comparing the results obtained in the analysis of slurries and digested brain samples, and by analysis of the NIST Bovine Liver standard reference material (SRM 1577a). The ease of slurry preparation, together with the conventional set of analytical and instrumental conditions selected for the determination of manganese make such methodology suitable for routine clinical applications.
已开发出一种通过石墨炉原子吸收光谱法测定人脑样本不同部位中锰的简单程序。脑部分包括小脑、下丘脑、额叶皮质、蚓部和脑干。评估了两种样品制备程序，即悬浮液进样和微波辅助酸消解。脑悬浮液（2% w/v）可在蒸馏去离子水中制备，在长达30分钟内具有良好的稳定性。脑样本也使用5毫升浓硝酸在家用微波炉中进行消解。无论基质如何，均使用钯+硝酸镁混合化学改进剂在电热原子化器中对分析物进行热稳定，直至1300℃的热解温度。两种情况下均通过水溶液标准校准对锰进行定量。悬浮液和消解样品的检测限分别为0.3和0.4 ng ml-1。通过比较悬浮液和消解脑样本分析所得结果以及分析NIST牛肝标准参考物质（SRM 1577a）来检查该程序的准确性。悬浮液制备的简便性，以及为测定锰而选择的常规分析和仪器条件，使得这种方法适用于常规临床应用。
