国产碳-11多功能模块全自动化合成~(11)C-乙酸盐

采用国产碳-11多功能合成模块,研究全自动化合成11 C-乙酸盐的工艺流程。用0.1mL 1.5mol/L的溴化甲基镁在Loop环中与11 C-CO2反应生成中间体乙酰溴化镁,中间体由乙酸水解,再经纯化、洗脱、盐酸酸化,通入氮气除去未反应的11 C-CO2,以磷酸三钠中和后过无菌滤膜得11 C-乙酸盐注射液。总合成时间约为10min,校正放化产率为(58.5±6.7)%,放化纯度大于99%。使用气相色谱仪测得产品中有机溶剂丙酮和乙腈的残留浓度分别为(0.007±0.002)%和(0.005±0.002)%。整个合成过程实现全自动化,操作简单、灵活,合成产率和放化纯度较高,可以满足临床使用需求。     

18F-硝基咪唑的放化稳定性

研究了乏氧显像剂¹⁸F-硝基咪唑（¹⁸F-FMISO）的全自动化合成方法,分析了影响¹⁸F-FMISO放化稳定性的因素。采用回旋加速器生产出来的¹⁸F^-,传输到住友CFN-MPS200合成装置中,经QMA柱捕获后淋洗到反应管,两次干燥除去水分,再与乙腈溶解的10 mg 1-（2’-硝基-1’-咪唑基）-2-氧-四氢呋喃基-3-氧-甲苯磺酰基-丙二醇（NITTP）进行亲核取代反应。反应液用盐酸水解后加缓冲溶液中和,进入制备型高效液相进行分离。流动相采用φ=15%的乙腈水溶液,流速3 mL/min,保留时间11 min。用旋转蒸发仪脱除溶剂,再用生理盐水溶解加入稳定剂得到18F-FMISO注射液。考察了不同活度、稳定剂、旋蒸温度对产品放化稳定性的影响,结果表明,不校正合成效率（EOS）为(45±5)%（n=20）,合成时间50 min,在抗坏血酸钠做为稳定剂的情况下,6 h后产品的放化纯度为95%;而抗坏血酸和乙醇不能在50 ℃以上作为稳定剂。¹⁸F-FMISO可以用CFN-MPS200合成模块全自动化合成,产品收率较高,工艺稳定,¹⁸F-FMISO在弱碱溶液中稳定性好,为肿瘤的乏氧显像提供了临床便利。     

应用于等离子体排灰气处理的甲烷水汽重整反应的热力学分析

Tokamak装置中的等离子体反应一段时间后,需对产生的排灰气进行净化处理,以回收其中的氘氚。目前拟采用甲烷水汽重整反应将化合态的氘氚转化为单质并回收。本文运用Gibbs自由能最小化方法,对应用于等离子体排灰气处理的水汽重整反应进行热力学分析,考查反应温度、原料比例、反应压力、O₂、CO₂、H₂、CO等因素对反应平衡的影响,确定了适宜的反应条件,即反应温度范围650～700 ℃,压力1×105 Pa,水碳比1.5～2.0。此外,原料气中O₂或CO₂的存在有利于减少积碳的生成量,并获得较高的氢同位素平衡转化率;H₂的存在对重整反应的热力学平衡无明显影响;CO的存在会使积碳量增加,对反应产生不利影响,在进入重整反应器前应将其去除。     

PET示踪剂~(11)C-氟马西尼的合成及质量控制

为制备满足临床应用需要的~(11)C-氟马西尼,以~(11)C-CH3I为甲基化试剂,使用国产PET-CM-3H-IT-I型模块对~(11)C-氟马西尼的制备及纯化方法进行改进。用液相法合成~(11)C-CH3I,研究反应溶剂、碱性强度、碱量、反应温度对合成效率的影响,优化~(11)C-氟马西尼的合成条件。优化后的条件为:先将~(11)C-CH3I在室温下通入含1mg去甲基氟马西尼前体和1mg氢化钠的200μL DMF溶液中,加热至55℃恒温反应2min。反应物经半制备HPLC分离收集粗产品,再经SEP-PAK C-18柱固相萃取,对产品质量进行分析。结果表明,以捕获~(11)C-CO2计算,~(11)C-氟马西尼合成时间为(26±2)min,经衰减校正后放化产率为(45±4)%(n=10),产品放化纯度大于99%,放射性浓度为370~550 MBq/mL,比活度为4.7TBq/mmol,产品细菌和热源检测结果符合规定。通过优化反应条件,大幅度提高了标记率,用国产合成模块能够制备高质量、高比活度的~(11)C-氟马西尼,满足临床应用需求。     

氦中痕量杂质气体气相色谱检测分析方法研究

为实现聚变堆氘氚燃料工艺气中痕量杂质气体组分的快速检测分析,需建立特殊的高精度在线气相色谱检测分析方法。以高纯氦作为载气,在不同的色谱柱温度和载气流速控制下,通过分子筛毛细管柱和PLOT-Q柱进行分离,采用放电氦离子化检测器（DID）进行检测,对氦中含量为1、10以及100 ppm的杂质标准气体进行检测分析。结果表明：在柱温为40 ℃、流速为15～20 mL/min实验条件下,分子筛柱在160 s内能够实现H₂、O₂、N₂、CH₄和CO全部分离,且柱效较高,响应值的重复性较好,H₂和O₂之间的分离度高于1.5,实现了完全分离;在柱温为40 ℃、流速为20 mL/min时,PLOT-Q柱分离CO₂组分效果最佳。     

自动化合成N-琥珀酰亚胺-4-[18F]氟苯甲酸酯

通过自动化多功能化学合成模块,在线合成N-琥珀酰亚胺-4-[¹⁸F]氟苯甲酸酯（[¹⁸F]SFB）。标记前体4-三甲基胺苯甲酸乙酯三氟甲基磺酸盐与干燥的¹⁸F^-发生亲核反应,生成4-[¹⁸F]氟苯甲酸乙酯,碱水解得到4-[¹⁸F]-氟苯甲酸（[¹⁸F]FBA）,经Sep-Pak C18固相柱分离,加O-(N-琥珀酰亚胺)N,N,N′,N′-四甲基脲四氟硼酸盐(TSTU)乙腈溶液反应,生成[¹⁸F]SFB, Sep-Pak C18固相柱分离得纯[¹⁸F]SFB。 在115 ℃,密封条件间隔通氮气加热10 min亲核反应,用NaOH水解保护基团,得到[¹⁸F]SFB的不校正合成效率为(28.2±1.9)% (n=5),放射化学纯度大于90%,总的合成时间为45 min。     

Optimization of the Radiosynthesis of the Dopamine Transporter Imaging Agent of11C-β-CFT

The optimization for high synthesis yield was designed with ¹¹C-Triflate-CH₃I as methylation agent for dopamine transporter imaging agent of¹¹C-β-CFT. The influence factors of the synthesis process were discussed, and the optimum synthetic conditions were established. In the paper, the study showed that the amount of precursor, the irradiation time, eluated condition, the reaction solvent etc could effect the synthetic efficiency.¹¹C-β-CFT was automatic synthesized on PET-CM-3H-IT-Ⅰ with the optimum process conditions as the irradiation time 10-24 minutes, 0.5-1.0 g/L of precursor in 0.2 mL acetone: acetonitrile(1∶1, V∶V) and room temperature. We obtained a radiochemical yield of (76.93±6.49)% (n=76,¹¹C-Triflate-CH₃ EOB). The radiochemical purity of final products were over 97%. The specific activities of final products were over （56.26±1.55） TBq/g. It took 16 minutes from¹¹C-CO₂ to¹¹C-β-CFT and the radio activity of¹¹C-β-CFT were (8.07±1.94) GBq (n=76). By optimization of the technological conditions, the target product was suitable for clinical, the synthetic process was reliable and full automated, the product yield was improved and the residual problem of Sep-Pak C18 was resloved.     

Photon yields and decay times of cross luminescence in ioniccrystals

The authors report on the scintillation properties of the ternary inorganic crystals KMgF₃, KYF₄:Rb, K₂YF ₅, KLuF₄, RbMgF₃, KZnF₃, BaTm₂F₈, LiYF₄:Nd, and BaF₂:Rb. The scintillation light output of these crystals was estimated from the X-ray-induced emission spectra. Optical absorption spectra and decay time spectra were also measured and are presented. The first four crystals produced cross-luminescence (CL) with a decay time of about 1.5 ns. CL was not observed for the other crystals     

钙-铀-碳酸络合物对红土吸附铀性能的影响

采用静态实验法研究了钙-铀-碳酸络合物对红土吸附铀性能的影响。结果表明:溶液的pH值、总碳酸和钙离子浓度增大会抑制红土对铀的吸附,当pH=7.0,红土投加量为1g/L,钙离子、总碳酸根和初始铀浓度分别为0.4mmol/L、3.8mmol/L和50mg/L时,红土对铀的最大吸附容量约为4.20mg/g。铀在红土上的吸附形态为UO2(CO3)2-2、UO2(CO3)4-3和UO2CO3(aq)。利用铀-碳酸络合物总量c(UCO3)T可预测红土吸附铀的容量qe,c(U-CO3)T与qe呈非线性关系,其方程为qe=18.2(c(UO2+2)·c(CO2-3)(K1+K2c(CO2-3)+K3c2(CO2-3)))0.36。该研究成果可为铀污染土壤的修复和治理提供技术和理论参考。     

~(11)C标记雷氯必利合成效率的影响因素

本文以11 C-Triflate-CH3为甲基化试剂,使用国产模块PET-CM-3H-IT-I合成11 C标记化合物雷氯必利(11 C-Raclopride),研究其合成过程中的碱量、溶剂、反应温度、前体量及产品淋洗条件对合成效率的影响,优化11 C-Raclopride的合成条件。优化后的合成条件为:以0.2mL丙酮为溶剂,前体浓度1.5~3.0g/L,反应温度为室温(25℃),碱量0.30~1.25eq,11 C-Raclopride的合成效率(64.82±4.74)%(n=46,以11 C-Triflate-CH3计校正效率),产品的放化纯度大于97%,比活度为(423.61±13.43)GBq/g,从收集11 C-CO2至得到11 C-Raclopride终产品的总合成时间为23 min,产量(6.9±0.87)GBq(n=46)。通过优化合成工艺,实现了稳定性和重复性良好的全自动化合成11C-Raclopride,且产品满足临床使用需要。     

Aβ显像剂18F-AV45的自动化合成及临床验证

使用进口氟多功能合成模块TRACERlab FX2 N合成器自动化合成β-淀粉样蛋白（β-amyloid protein, Aβ）正电子显像剂¹⁸F-AV45,并进行临床验证。在TRACERlab FX2 N合成器上,以AV105为前体,与18F-发生亲核反应后,依次经酸水解及碱中和,经过高效液相色谱法（high performance liquid chromatography, HPLC）分离并纯化后获得¹⁸F-AV45,进行质量控制。并用制备的¹⁸F-AV45对1例阿尔兹海默病（Alzheimer disease, AD）患者及1例健康对照者行¹⁸F-AV45 PET/CT扫描。结果表明,¹⁸F-AV45合成时间为80 min,不校正合成效率为（17.02±1.52）%（n=6）,产品放化纯度大于95%。临床应用显示¹⁸F-AV45在AD患者大脑皮层摄取弥漫增高,提示大脑皮层β淀粉样蛋白沉积;在健康对照者大脑皮层未见明显摄取,即大脑皮层未见β淀粉样蛋白沉积。TRACERlab FX2 N合成器自动化合成¹⁸F-AV45简便快捷,重复性好,制备出的¹⁸F-AV45产品质量符合临床要求,该合成方法可为¹⁸F-AV45模块合成提供参考。     

肼为还原剂催化还原U(Ⅵ)制备U(Ⅳ)的工艺条件

研究了硝酸体系中以铂黑为催化剂、肼为还原剂还原制备U(Ⅳ)的工艺条件,考察了硝酸浓度、肼浓度、反应温度、催化剂用量等对U(Ⅵ)转化率及副反应的影响。当铀浓度为0.90mol/L时,优化的工艺条件为：初始硝酸浓度0.80mol/L,初始肼浓度1.0mol/L左右,反应温度60℃,反应液25mL时催化剂铂黑用量为0.2g,反应3h后U(Ⅵ)的转化率大于99%。     

Li4TixSi1-xO4氚增殖陶瓷制备及力学性能

正硅酸锂材料锂密度高、释氚性能好,是国际热核聚变实验堆(ITER)主要的候选氚增殖剂材料.通过异质元素掺杂,形成固溶体结构,可提高陶瓷抗压强度.本研究采用固相法合成陶瓷粉体,通过熔融喷雾工艺制备获得密度高、球形度好的Li4 Tix Si1-x O4固溶体陶瓷小球.Ti原子固溶可以改善陶瓷微观结构,提升力学性能.研究结果...     

超临界水氧化处理核电站废阴离子交换树脂研究

在间歇式超临界水氧化(SCWO)设备中,对粉碎处理后的阴离子交换树脂水悬浮液在超临界条件下进行了氧化降解处理。实验研究了反应温度、反应压力、反应时间、过氧系数对COD去除率的影响,同时考察了催化剂种类、反应压力和反应温度对氨氮去除率的影响。通过正交试验,得到主要因素对处理效果影响的显著程度排序为:反应温度>反应压力>反应时间>过氧系数。结果表明:在反应温度540 ℃、反应压力26 MPa、反应时间8 min、过氧系数3的条件下,COD去除率为99.65%。针对阴离子树脂中NH₃-N含量高难以去除的问题,选用不同的催化剂CuSO₄、MnO₂、CeO₂添加到反应体系中,结果表明对NH₃-N的氧化效果顺序为CuSO₄>CeO₂>MnO₂,对NH₃-N的最高降解率达到96.53%。     

Full Automated Synthesis of18F-FDOPA and Preliminary PET/CT Imaging

¹⁸F-fluoro-L-dihydroxyphenylalanine (¹⁸F-FDOPA) as a dopamine neurotransmitter imaging agent has been widely used for diagnosis and therapy evaluation of Parkinson's disease, brain tumors and neuroendocrine diseases with positron emission tomography (PET) imaging in clinical setting and research. To meet the increasing clinical demand in oncology and neurology, a routine protocol for the automated synthesis of¹⁸F-FDOPA with a disposable cassette system on an imported multifunctional synthesizer was studied and discussed.¹⁸F-FDOPA was automatically synthesized via a multiple-step reaction, including fluorination, reduction, iodization alkylation and hydrolysis, following purification by using a semi-preparative high-performance liquid chromatography (HPLC) system which was built in the multifunctional synthesizer. After HPLC purification, the purified¹⁸F-FDOPA solution was collected and passed through a sterilizing filter into a collection bottle. The final¹⁸F-FDOPA injection was obtained for quality control (QC) determination. The QC indexes of the final products were detected： the injection was colorless and transparent, pH value was at 4 to 5.5, radiochemical purity >98%, radionuclide purity >99%, specific activity >1.9 GBq/μmol, K_2.2.2 content <50 mg/L, methanol content <0.01%, alcohol content <0.01%, dichloromethane content <0.01 mg/L, dimethylformamide content <15 mg/L, bacterial endotoxin test <0.100 EU/mL, sterility test 0 cfu/mL,and abnormal toxicity test was negative. PET/CT imaging of rats was performed by intravenous injection of¹⁸F-FDOPA half an hour after the intraperitoneal injection of carbidopa, PET/CT scan was performed after 100 min post-injection. The imaging of¹⁸F-FDOPA showed symmetry high uptake in the bilateral striatum of normal rats. The decay-corrected radiochemical yield of¹⁸F-FDOPA from the¹⁸F-fluoride was (63.1±3.8)% (n=10) at the end of synthesis (EOS), the radiochemical purity was no less than 98%, and the total radiosynthesis time was within 80 min. The quality control results demonstrated that the quality indexes of the final injection solution met the relevant requirements of radiopharmaceutlcals, which were well-suited for clinical application. An efficient and high reproducible automatic method for the radiosynthesis of¹⁸F-FDOPA with high radiochemical yields and good radiochemical purity is obtained and performed via a multi-step reaction on the multifunctional synthesizer.¹⁸F-FDOPA can be used for animal and human PET imaging.     

溶解硫酸盐硫同位素测试预处理方法优化

为分析水体中硫酸盐硫同位素组成,常将SO2-4转化为固体BaSO4,进行预处理,但是该方法对体积少且低浓度硫酸盐样品(0～20 mg·L-1)存在耗时长、回收率低等问题,对硫同位素测试结果的影响仍不明确.本文通过对不同Ba2+添加量、反应温度、pH和沉淀时间等条件对SO2-4回收率及δ34 SBaSO4测试影响进行研究...     

新型铯选择性吸附剂的合成及性能

在金属镍粉表面原位合成了与金属基体紧密结合的亚铁氰化镍钾(KNiFC/Ni)吸附剂。经分析,其表面为面心立方晶系的亚铁氰化镍钾(KNiFC),厚度约为40~80nm,晶格参数为0.996 0nm,化学组成可表示为K1.4Ni1.3Fe(CN)6。结果表明:该吸附剂不水解,对137 Cs具有较高的吸附容量,非常快的吸附速率,很高的选择性,Cs的吸附分配系数(Kd)可达105 mL/g,即使在1.0mol/L NaNO3溶液中,Kd值也大于103 mL/g;该吸附剂吸附137 Cs为典型的离子交换机制,NH+4由于具有和Cs+相近的离子半径所以竞争最为强烈。本吸附剂有望用于含铯废液的处理及137 Cs的分离或提取。     

Segregation effects on the corrosion behaviour of a phosphorus-doped AISI type 304L stainless steel

The effect of grain boundary (GB) segregation on intergranular stress corrosion cracking (IGSCC) in hot water environments at 150°C and 250°C was studied in a P-doped AISI type 304L stainless steel. The extent of segregation was measured by an exposure test in boiling 5 N HNO₃ + 8g/L K₂Cr₂O₇ solution as well as by a potentiostatic etch test at +1325 mV (SHE) in 5 N H₂SO₄ solution. Although GB segregation was detected in all the aged specimens, IGSCC was shown by only the specimens aged for 550°C/1000 h. The results suggest that it is the GB chromium depletion, rather than the segregation of phosphorus at the GBs, that controls IGSCC of stainless steels in the hot water environments studied.     

国产FDG模块半自动合成~(18)F-氟乙基胆碱

18F-氟乙基胆碱(18F-FECH)是18F-FDG的重要补充,在脑瘤转移和前列腺癌及转移的诊断方面有重要的应用价值。利用国产单次PET-FDG-TI-I CPCU型FDG合成模块,未改变硬件,通过更改试剂与耗材,半自动合成18F-FECH,并在产品收集瓶前增加C18纯化柱,减少K2.2.2杂质的含量。合成时间约30min,放化产率42.0%(未时间校正,n=5),放置6h后放化纯度99.0%,体外稳定性良好;合成时间和产率与国内外模块结果相近。结果表明,在国产单次PET-FDG-TI-I CPCU型FDG模块上可半自动合成18F-FECH,合成效率及放化纯度较高。     

整体式除氚催化剂的制备及催化氧化性能

针对大型核设施产生的大流量废气的处理,发展低气阻的整体式催化剂尤为必要.本工作在整体式堇青石载体上生长分子筛涂层,以离子交换法负载活性组分Pt,获得的整体式催化剂具有高的金属分散度,达到了60％.使用该催化剂,在15℃、体积空速为10000～40000 h-1、1.0％(体积分数)H2的条件下实现大于99.9％ 的H2...