一种空气中^(14)C监测技术

A TECHNIQUE OF MONITORING ^(14)C IN AIR

本文主要介绍用于监测空气中14 C的“CO2 碱液吸收 CaCO3悬浮液闪计数法”的原理、条件实验和最小可探测水平 ,在采样 2m3空气 ,测量时间 3 0 0min的条件下 ,按通常的方法计算的空气中14 C活度浓度最小可探测水平约为 0 .0 1 7Bq/m3(空气 ) [或 0 .0 9Bq/g(碳 ) ],约是实测的环境本底的 2 /5。

This article introduces the principle,experimental conditions and lower detection limit of “CO_2 absorbed by NaOH solution-CaCO_3 suspended in the liquid scintillation solution and counting”,a method of monitoring 14C activity in air. Under the condition of sampling 2 m 3 air and measuring time of 300 min,the lower detection limit of 14C activity in air is about 0.017 Bq/m 3 (or 0.09 Bq/g carbon),it is 2/5 of enviromental background in Hangzhou.