Kawae M, Wada M, Mori K, Sasaki Y, Kano E
Radioisotope Research Institute, Fukui Medical University School of Medicine.
Radioisotopes. 1987 Jun;36(6):286-9. doi: 10.3769/radioisotopes.36.6_286.
A simplified monitoring method of 125I in liquid waste was devised. The waste water of 200 cm3 was taken on a Saran (polyvinylidene chloride) film covering a stainless steel vat. A stable iodine (20 mg) and sodium hydroxide (1 mmol) was added. The water was evaporated using an infra-red lamp. After heating to dryness, the Saran film was folded and transferred into a polyethylene tube. The radioactivity of 125I was counted with a well type NaI(Tl) scintillation counter. When a multi-channel analyzer was available for counting, an absolute decay rate of 125I was calculated with single and sum photo-peak counts. The radioactivity of 125I counted by a single-channel counter must be corrected with the counting efficiency of about 55%, with a special emphasis of a self absorption of photons. The recovery of 125I for concentrations below the permissible level was more than 98%.
设计了一种简化的废液中¹²⁵I监测方法。取200 cm³废水置于覆盖不锈钢桶的莎纶（聚偏二氯乙烯）薄膜上。加入稳定碘（20 mg）和氢氧化钠（1 mmol）。使用红外灯蒸发水分。加热至干燥后，将莎纶薄膜折叠并转移至聚乙烯管中。用井型NaI（Tl）闪烁计数器对¹²⁵I的放射性进行计数。当有多道分析仪用于计数时，通过单光峰计数和总光峰计数计算¹²⁵I的绝对衰变率。单道计数器计数的¹²⁵I放射性必须用约55%的计数效率进行校正，尤其要考虑光子的自吸收。¹²⁵I在低于许可水平浓度下的回收率超过98%。
