生物样品主要成分组成对γ能谱无源效率刻度的影响

目的 评估生物样品主要成分组成对γ能谱分析时无源效率刻度的影响。方法 依据新鲜生物体内O、C、H、N主要元素占细胞总量的比例（分别为65%、18%、10%、3%）估算新鲜生物样品中各元素相应含量，然后再根据样品脱水比例估算相应样品中O、C、H、N的含量。各种模拟样品信息通过LabSOCS无源效率刻度软件生成效率曲线，由此得到不同能量线的效率，经SPSS软件统计分析后评估O、C、H、N主要元素对无源效率刻度的影响。结果 对46.54 keV～1836.01 keV范围的能量线来说，新鲜生物样品与修正质量含量后的不同程度脱水样品无源效率刻度效率值的相对标准偏差为0%～0.86%，相对偏差绝对值最大值为2.6%；模拟O、C、H、N 4种单质元素样品无源效率刻度效率值的相对标准偏差为5.1%～13.2%；模拟O、C、N 3种单质元素样品对无源效率刻度效率值影响两两相比，相对偏差绝对值最大值分别为4.6%、2.7%和1.9%，而H单质元素样品与其它3种单质元素分别比较，相对偏差绝对值最大值分别为27.0%、28.9%和28.4%。结论 新鲜生物样品中O、C、N 3种元素对无源效率刻度影响程度相近，而H元素对无源效率刻度影响程度与O、C、N 3种元素不同，总体上生物样品脱水前后对无源效率刻度的影响不大，在容许接受范围之内。

Effect of main components of biological samples on sourceless efficiency calibration of gamma spectrometry

Objective This study aimed to evaluate the effect of the main components of biological samples on the sourceless efficiency calibration in gamma spectrum analysis. Methods The contents of O, C, H and N in the fresh biological samples were estimated according to the proportion of each element in the total amount of cells origin from fresh biological samples (65%, 18%, 10% and 3% respectively), then the contents of O, C, H and N in corresponding samples were estimated according to the dehydration proportion of samples. The efficiency curve of different energy lines derived from various simulated sample information was generated using LabSOCS sourceless calibration software. Statistical analysis was performed by SPSS software, and the influence of major elements (O, C, H, and N) on the sourceless efficiency calibration was evaluated.Results For the energy line in the range of 46.54 keV ～ 1836.01 keV, the efficiency value of the sourceless efficiency calibration of the fresh biological sample was compared with that of samples with different degrees of dehydration whose mass content had been modified. The relative standard deviation was 0% ～ 0.86%, and the maximum value of the absolute value of the relative deviation was 2.6%. For the simulated single-element O, C, H and N samples, the relative standard deviation of the efficiency value of the sourceless efficiency calibration was 5.1% ～ 13.2%. The pairwise comparison was done with the efficiency value of sourceless efficiency calibration obtained from the simulated single-element O, C, N samples. The maximum value of the relative deviation of the absolute value was 4.6%, 2.7% and 1.9%, respectively. Single-element H sample was compared with other three single-elemental samples, and the maximum relative deviation of the absolute value was 27.0%, 28.9% and 28.4%, respectively.Conclusion For the fresh biological samples, the influences of O, C and N elements on the sourceless efficiency calibration are similar, while the influence of H element on the sourceless efficiency calibration is different from that of O, C and N elements. Generally, the dehydration treatment of biological samples exerts a slight influence on the sourceless efficiency calibration, and the variation falls within the acceptable range.