定量电子束显微分析中生物薄样品的质量损失

MASS LOSS OF QUANTITATIVE ELECTRON PROBE X RAY MICROANALYSISFOR BIOLOGICAL THIN SPECIMEN

对多种生物薄样品和标样进行电子探针X射线能谱显微定量分析 ,分别以电子束轰击后样品的OKα峰计数和介于4.2 -6.2keV区间的连续X -射线计数变化监测质量损失 ,结果显示样品OKα峰计数减少幅度大于连续X -射线计数减少幅度 ,在相同的分析条件下 ,各样品质量损失程度不相同 (P<0.05) ,培养肝癌细胞冷冻干燥超薄切片、明胶冷冻干燥超薄切片、BSA薄膜、氨基塑料超薄切片、红细胞冷冻干燥超薄切片和卵黄高磷蛋白薄膜样品的质量损失分别为33 %、28 %、26 %、18 %、13 %和13 % ,以上结果提示 :以OKα峰计数的减少监测样品的质量损失较敏感 。

s: The O Kα peak counts and continuum counts within 4.2-6.2 keV were used to monitor the mass loss extent of thin biological ultra cryosections and standards during electron probe X ray microanalysis respectively, these results show that the O Kα peak counts declines more steeply than continuum counts(P<0.05). Under the same electron irradiation, not all the samples lose mass to the same extent(P<0.05). Cultured liver carcinoma cell dried cryosections, gelatin dried cryosections, BSA films, aminopastic thin sections, eryothrocyte cryosections and phosvitin films lose 33%,28%,26%,18%,13% and 13% respectively. These results suggest that (1) the O Kα peak counts decrease is more sensitive than continuum counts alteration, (2) the mass loss extent should be corrected during quantitative electron probe X ray microanalysis.