MEASUREMENT OF TOTAL BODY PROTEIN, FAT AND WATER USING IN VIVO NEUTRON ACTIVATION ANALYSIS

简介：体内中子活化分析(IVNAA)设备已经建立，能够对身体的组成部分进行准确和精确的测量。商用紧凑型伴生粒子密封管中子发生器(APSTNG)的结果表明，通过测量总碳、总氮和总氧的质量，可以同时测定总蛋白质、总脂肪和总水。方法：APSTNG及其高压控制系统由美国斯普林菲尔德核诊断系统公司提供。样品在距APSTNG 30 cm的距离处照射并计数15分钟。水的化学分析采用冷冻干燥法，脂肪的化学分析采用石油醚索氏提取法，灰分的化学分析采用600℃燃烧法，蛋白质的化学分析采用凯氏定氮法。结果：蛋白质、脂肪和水的IVNAA测定结果与化学分析结果吻合较好。摘要基于APSTNG的活体成分测量仪器可以组装。它的使用将使在15分钟内准确地同时测量全身的蛋白质、脂肪和水分成为可能。

Introduction : In vivo neutron activation analysis (IVNAA) facilities have been set up enabling accurate and precise measurements to be made of the components of the body. A compact associated particle sealed tube neutron generator (APSTNG) is commercially available arid the results show that total body protein, total body fat, and total body water could be determined simultaneously by measuring the mass of total body carbon, total body nitrogen, and total body oxygen present. Methods : The APSTNG and its high voltage control system were supplied by Nuclear Diagnostic Systems Inc., (Springfield, VA, USA). The samples were irradiated at a distance of 30 cm from the APSTNG and counted for 15 minutes. The chemical analysis of water was performed by freeze drying, fat by soxhlet extraction with petroleum ether, ash by combustion at 600℃ and protein by the Kjeldahl method. Results: There is good agreement between the IVNAA and chemical analysis results for protein, fat and water. Summary An instrument based on the APSTNG for measuring the composition of body in vivo can be assembled. Its use would make possible the simultaneous measurement of protein, fat and water in the whole body to good precision within a 15 minutes scan.