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PET探针13N-氨水在临床被广泛应用于心肌血流测定和局部脑血流显像,13N-氨水联合18F-FDG心肌显像已成为评价心肌存活的影像学金标准[1]。而且,临床还发现,13N-氨水对脑胶质瘤[2]、无症状的纤维肉瘤[3]和星型细胞瘤[4]的检测比18F-FDG更有独特的优势,其在临床上的应用范围日益扩展。
作为被中国药典收录,可以进行临床应用的12种静脉注射的正电子显像剂之一的13N-氨水,与目前临床最常用的18F-FDG一样,在使用前必须进行药物的系列质量控制,其中,对药物进行鉴别和放射化学纯度的检测是其中最重要的常规质控之一。但是,由于13N-氨水的化学量是痕量的,而13N的半衰期极短,只有10 min,所以要求鉴别确认和放射化学纯度的检测过程必须快速、简单。目前,国内对13N-氨水还没有出台相关的质量标准和检测方法,美国药典推荐了13N-氨水的鉴别和放射化学纯度的检测方法——使用氯化铵(NH4Cl)作为标准液,电导池检测器作为检测器进行13N-氨水的鉴别确认和放射化学纯度的检测[5]。由于受检测器的限制,该方法难于普及。本研究使用最常用的高效液相色谱(high performance liquid chromatography,HPLC)紫外(ultraviolet,UV)检测器,对13N-氨水进行了有效的鉴别确认和放射化学纯度的分析,现报道如下。
高效液相色谱与放射性流动计数器联用确证13N-氨水及测定放射化学纯度的研究
Identification of 13N-NH3 and analysis of its radiochemical purity using high performance liquid chromatography-ultraviolet-flow-count
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摘要:
目的 建立新的快速鉴别正电子显像剂13N-氨水及测定其放射化学纯度的有效方法。 方法 采用高效液相色谱-紫外检测器联用放射性流动计数器(HPLC-UV-Flow-Count)的方法,以12.5%的氨水和0.1 mg/ml硝酸钠(NaNO3)作为标准液,AQ-C18柱为分离柱,流动相为5 mmol/L的辛烷磺酸钠水溶液和乙腈(体积比为3:1),流速为0.5 ml/min,紫外吸收波长为210 nm。将氨水和硝酸钠标准液进样检测,得到它们的色谱图后对比保留时间进行鉴别。 结果 在上述的洗脱条件下,氨水和硝酸钠的UV保留时间分别为2.3和1.4 min,13N-氨水和杂质13N-NOx-的放射性保留时间分别为5.8和3.1 min,两种物质分离良好。放射性显像剂13N-氨水的放射化学纯度大于95%,符合临床应用的要求。 结论 该方法简单、快速,适合半衰期极短的13N-氨水正电子显像剂的鉴别和放射化学纯度的测定。 Abstract:Objective To establish a new, rapid, and effective method to identify 13N-NH3 and analyze its radiochemical purity. Methods The chromatographic method of high performance liquid chromatography-ultraviolet(HPLC-UV)-flow-count was performed using a C18 column with mobile phase of acetonitrile and 5 mmol/L sodium 1-octanesulfonate solution(V/V=1/3)at a flow rate of 0.5 ml/min and a wavelength of 210 nm. 15% 13N-NH3 and 0.1 mg/ml NaNO3 were detected separately, and their retention times were compared and identified. Results The UV retention times of NH3 and NaNO3 were 2.3 and 1.4 min, respectively, and the retention times of 13N-NH3 and 13N-NOx- were 5.8 and 3.1 min, respectively. The established separation method using HPLC-UV-flow-count showed good efficiency. Conclusion HPLC-UV-flow-count is a simple, valid, and rapid method to identify 13N-NH3 and analyze its radiochemical purity. -
Key words:
- Chromatography, high pressure liquid /
- 13N-NH3 /
- Radiochemical purity
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[1] Ryzhkova DV, Krasil′nikova LA, Nifontov EM, et al. Evaluation of coronary bed function by positron emission tomography using 13N-ammonium during cold stimulation[J]. Vestn Rentgenol Radiol, 2011, 3(1):30-35. [2] Shi X, Liu Y, Zhang X, et al. The comparison of 13N-ammonia and 18F-FDG in the evaluation of untreated gliomas[J]. Clin Nucl Med, 2013, 38(7):522-526. doi: 10.1097/RLU.0b013e318295298d [3] Harisankar CN, Mittal BR, Watts A, et al. Utility of dynamic perfusion PET using 13N-ammonia in diagnosis of asymptomatic recurrence of fibrosarcoma[J]. Clin Nucl Med, 2011, 36(2):150-151. [4] Xiangsong Z, Changhong L, Weian C, et al. PET imaging of cerebral astrocytoma with 13N-ammonia[J]. J Neurooncol, 2006, 78(2):145-151. doi: 10.1007/s11060-005-9069-x [5] The United States Pharmacopeial Convention. United States Pharmacopoeia(USP 35)[Z]. 2010. [6] Berridge MS, Landmeier BJ. In-target production of [13N] ammonia:target design, products, and operating parameters[J]. Appl Radiat Isot, 1993, 44(12):1433-1441. doi: 10.1016/0969-8043(93)90096-S [7] 鄢敏, 秦志星, 程鹏亮, 等.住友CLC模块在线优化合成13N-NH3·H2O的研究[J].国际放射医学核医学杂志, 2014, 38(6):360-362.
[8] Firouzbakht ML, Schlyer DJ, Wolf AP, et al. Mechanism of nitrogen-13-labeled ammonia formation in a cryogenic water target[J]. Nucl Med Biol, 1999, 26(4):437-441. doi: 10.1016/S0969-8051(99)00002-5 [9] Krasikova RN, Fedorova OS, Korsakov MV, et al. Improved [13N]ammonia yield from the proton irradiation of water using methane gas[J]. Appl Radiat Isot, 1999, 51(4):395-401. doi: 10.1016/S0969-8043(99)00062-7 [10] Okada M, Nakao R, Hosoi R, et al. In vivo monitoring of extracellular 13N-glutamine derived from blood-borne 13N-ammonia in rat striatum using microdialysis with radio-LC method[J]. J Neurosci Methods, 2009, 184(1):37-41.