A STUDY ON THE SAMPLE PREPARATION TECHNIQUES TO IMPROVE VARIATION ANALYSIS OF HYDROGEN AND CARBON ISOTOPES IN ENVIRONMENT

我们研究了样品制备技术，以开展环境中氢和碳同位素的变化分析。取得的结果如下：1.研究成果。测量环境水样中的低氚浓度，离不开对其进行电解富集。将样品池与标准池串联，计算出样品的氚浓度，测量标准池中的仪器常数k或回收率R，以及样品槽中电解后的氚浓度等。结果表明，这两种方法对环境水样中氚浓度的估算同样有效。这一结果已在2001.2筑波举行的第六届国际氚科学与技术会议上发表。由于化学方法制备14&C样品耗时较长，采用常规工艺一周只能制备两个样品。因此，我们将化学过程…更多的是分为三个部门，如活化钒催化装置，形成碳化锂的电炉和乙炔-苯制备装置。因此，如果三道工序同时进行，我们可以在一周内制备四个样品。最近，人们希望对碳同位素的分馏效应进行校正，并将其校准到日历年。我们在《八野河理工学院公报》第21卷，2002.4期上报道了一些应用于木炭样品的例子。调查了八尺河地区一些交通条件不同的地区蒲公英叶片中的14&gt；C浓度，证实了蒲公英的14&gt；C浓度与当地的交通条件相吻合。对八野河理工学院2000年1月至2001年12月在校园内采集的所有降水样品的氢稳定同位素比δD进行了研究。发现了δD的季节变化，并用“Yamase”的温度效应和降水的生长位置3个因素解释了这种变化。较少

We studied sample preparation techniques to develop variation analysis of hydrogen and carbon isotopes in environment. Obtained results are as follows.1. To measure low tritium concentration in environmental water samples, it is indispensables to enrich them by electrolysis. We enriched water samples connected a sample cell and a standard cell in series and calculated tritium concentration of the sample measuring an apparatus constant k or a recovery factor R in the standard cell as well as tritium concentration after electrolysis and so on in the sample cell. It was demonstrated that these two methods were equally effective to estimate tritium concentration in environmental water samples. This result has been reported in 6th international conference on tritium science and technology, held at Tsukuba, 2001.2. Since it takes much time for chemical preparation of ^<14>C samples, only two samples can be prepared in one week by a conventional process. We therefore divided the chemical proc … More ess into three divisions such as a device to activate vanadium catalysis, an electric furnace to form lithium carbide and acetylene-benzene preparation apparatus. As the result, we could have an ability of preparing four ^<14>C samples in a week, if we operate the three processes simultaneously.3. Recently it is desirable for ^<14>C ages to correct the fractionation effect of carbon isotopes and also to calibrate them to calendar year. We reported some examples applied to charcoal samples on the bulletin of Hachinohe Institute of Technology, Vol. 21, 2002.4. We investigate ^<14>C concentration in the leaves of Dandelion growing in some locations of Hachinohe area where traffic circumstances are differ from one another and confirmed that ^<14>C concentrations of Dandelion correspond to the local traffic conditions.5. We studied hydrogen stable isotope ratio, δD in every precipitation samples collected on the campus in Hachinohe Institute of Technology from Jan. 2000 to Dec. 2001. We found the seasonal variation of δD and interpreted the variation by three factors, that is, temperature effect of "yamase" and the growing location of precipitation. Less