环境样品中氟的测定

目的　建立一种快速、准确的高温燃烧水解 氟离子选择电极法测定煤、头发和食物中氟的方法。方法　对影响高温燃烧水解的因素如石英砂用量、水解时间、水解温度、蒸馏水体积以及称样量进行了比较系统的研究 ,并且确定了最佳试验条件。结果　本法高温燃烧水解时间比中华人民共和国标准GB T4 6 33 1997降低了 1 3,采用杨树叶、茶叶、煤标准参照物及辣椒、玉米等样品测定了方法的精密度和准确度 ,相对标准偏差 <5 % ,回收率 90 3%～ 10 7 6 %。结论　本方法适用于各种环境样品中氟的测定。     

广饶、博兴两县地方性氟中毒病情现况分析

[目的]掌握地氟病的病情动态和改水降氟情况,更好地指导地氟病防治工作。[方法]2003年,对已实行降氟改水的博兴、广饶两县9个氟病村,检测饮水氟含量;检查8～12岁儿童氟斑牙患病情况,测尿氟含量。[结果]9个村中,8个村水氟含量超标。广饶县凋查152名儿童,氟斑牙患病率为48.0%,斑釉指数为1.02;博兴县调查251人,氟斑牙患病率为60.0%,斑釉指数为1.31。广饶县检测87名儿童,尿氟含量几何均值为2.32mg/L;博兴县检测47名儿童,尿氟含量几何均值为3.07mg/L,均超过正常值。[结论]2县水氟含量仍然超标,氟中毒病情严重。     

18F-FDG符合线路SPECT显像在胃肠道恶性肿瘤术后的应用

目的探讨^18F—FDG符合线路SPECT显像在探测胃肠道恶性肿瘤术后复发和远处转移中的应用价值。方法24例胃肠道恶性肿瘤术后患者，其中食管癌4例，胃癌7例，结肠癌6例，直肠癌7例，运用SIEMENS ECAM^deut SPECT仪进行^18F—FDG显像。结果^18F—FDG显像诊断胃肠道恶性肿瘤术后转移和复发的灵敏度为94．7％，特异性80．0％，准确性91．7％。在^18F—FDG显像真阳性18例中，2例为局部复发，5例为局部复发伴转移，11例为远处转移。在有复发的7例患者中，5例^18F—FDG显像结果与CT检查结果一致，2例CT检查局部未见异常，在有转移的16例患者中，共检出转移灶55处。结论符合线路SPECT仪^18F—FDG显像是检测胃肠道恶性肿瘤术后复发和转移的敏感而有效的方法。     

Synthesis of [18F]‐labeled adenosine analogues as potential PET imaging agents

The syntheses of adenosine analogues, 2′‐deoxy‐2′‐[¹⁸F]fluoro‐9‐β‐D ‐arabinofuranosyladenine ([¹⁸F]‐FAA) and 3′‐deoxy‐3′‐[¹⁸F]fluoro‐9‐β‐D ‐xylofuranosyladenine ([¹⁸F]‐FXA) are reported. Adenosine ( 1 ) was converted to its methoxytrityl derivatives 2 and 3 as a mixture. After separation, these derivatives were converted to their respective triflates 4 and 5 . Each triflate was reacted with tetrabutylammonium[¹⁸F]fluoride to produce 6b or 7b , which by acidic hydrolysis yielded compounds 8b and 9b . Crude preparations were purified by HPLC to obtain the desired pure products. The radiochemical yields were 10‐18% decay corrected (d. c.) for 8b and 30‐40% (d. c.) for 9b in 4 and 3 runs, respectively. Radiochemical purity was >99% and specific activity was >74 GBq/μmol at the end of synthesis (EOS). The synthesis time was 90‐95 min from the end of bombardment (EOB). Copyright © 2003 John Wiley & Sons, Ltd.     

Radiosynthesis of [18F]PBR111, a selective radioligand for imaging the translocator protein (18 kDa) with PET

PBR111 (2‐(6‐chloro‐2‐(4‐(3‐fluoropropoxy)phenyl)imidazo[1,2‐a]pyridin‐3‐yl)‐N,N‐diethylacetamide) is a novel, reported, high‐affinity and selective ligand for the translocator protein (18 kDa). PBR111 has been labelled with fluorine‐18 (half‐life: 109.8 min) using our Zymate‐XP robotic system. The process involves (A) a simple one‐step tosyloxy‐for‐fluorine nucleophilic aliphatic substitution (performed at 165°C for 5 min in DMSO using K[¹⁸F]F‐Kryptofix^®222 and 6.8–7.6 µmol of the corresponding tosylate as precursor for labelling) followed by (B) C‐18 PrepSep cartridge pre‐purification and (C) semi‐preparative HPLC purification on a Waters Symmetry^® C‐18. Up to 4.8 GBq (130 mCi) of [¹⁸F]PBR111 could be obtained with specific radioactivities ranging from 74 to 148 GBq/µmol (2–4 Ci/µmol) in 75–80 min (HPLC purification and SepPak^®‐based formulation included), starting from a 37.0 GBq (1.0 Ci) [¹⁸F]fluoride batch. Overall non‐decay‐corrected isolated yields were 8–13% (13–21% decay‐corrected). Copyright © 2008 John Wiley & Sons, Ltd.     

磷矿伴生氟资源的综合利用

随着我国氟化工行业的高速发展,氟资源枯竭加快,应回收利用好磷矿中丰富的氟资源.重点介绍国内外用氟硅酸生产氟硅酸盐、氟化盐的生产技术以及氢氟酸/无水氟化氢的专利技术和云南云天化国际化工股份有限公司在磷矿伴生氟资源综合利用方面所取得的科研成果,并对今后开展磷矿伴生氟资源综合利用提出建议.     

2005年滨州市地方性氟中毒病情调查

[目的]了解滨州市饮水型地方性氟中毒(地氟病)病区病情现状,为今后的防治工作提供科学依据.[方法]2005年,对滨州市惠民、博兴、邹平3县地氟病病区进行儿童氟斑牙患病情况调查与饮用水氟含量检测.[结果]合计调查8～12岁儿童1467名,检出可疑氟斑牙225人、氟斑牙患者653人(极轻氟斑牙225人,轻度氟斑牙204人,中度氟斑牙194人,重度氟斑牙30人),患病率为44.51%,斑釉指数为0.99;氟斑牙缺损率为9.82%.氟斑牙患病率,改水降氟工程报废病区(63.50%)、改水降氟工程正常运转病区(58.20%)均高于未改水病区(25.20%)(P＜0.01);改水工程报废停用病区不同年龄儿童氟斑牙患病率的差异无统计学意义(P＞0.05).饮用水含氟量(mg/L),改水工程报废病区为(2.24±1.21),改水工程正常病区为(1.34±1.05)(P＜0.05);未改水病村为(1.00±0.76),低于改水工程报废病区(P＜0.01).[结论]滨州市地氟病病区病情仍然较重.     

Trifluoromethanesulfonic acid,an alternative solvent medium for the direct electrophilic fluorination of DOPA: new syntheses of 6‐[18F]fluoro‐L‐DOPA and 6‐[18F]fluoro‐D‐DOPA

Previous work from this laboratory has shown that the direct fluorination of 3, 4‐dihydroxy‐phenyl‐L ‐alanine (L ‐DOPA) in anhydrous HF (aHF) or BF₃/HF with F₂ is an efficient method for the synthesis of 6‐fluoro‐L ‐DOPA. Since then, ¹⁸F‐labeled 6‐fluoro‐L ‐DOPA ([¹⁸F]6‐fluoro‐L ‐DOPA) has been used to study presynaptic dopaminergic function in the human brain and to monitor gastrointestinal carcinoid tumors. This work demonstrates that the reactivity and selectivity of F₂ toward L ‐DOPA in CF₃SO₃H is comparable with that in aHF. This new synthetic procedure has led to the production of [¹⁸F]fluoro‐L ‐DOPA and [¹⁸F]fluoro‐D‐DOPA isomers in 17±2% radiochemical yields (decay corrected with respect to [¹⁸F]F₂). The 2‐ and 6‐FDOPA isomers were separated by HPLC and subsequently characterized by ¹⁹F NMR spectroscopy. The corresponding [¹⁸F]‐FDOPA enantiomers have been obtained in clinically useful quantities by a synthetic approach that avoids the use of aHF. Copyright © 2007 John Wiley & Sons, Ltd.     

New radiolabelling chemistry: synthesis of phosphorus–[18F]fluorine compounds

The feasibility of synthesizing compounds containing the P–¹⁸F bond has been demonstrated by labelling the pesticide, cholinesterase inhibitor Dimefox (N,N,N′N′‐tetramethylphosphorodiamidic fluoride) with F‐18. Radiolabelling was achieved in high radiochemical yield (96%) by nucleophilic substitution of the chloro group attached to phosphorus, in the oxidation state P(V), by ¹⁸F^? (activated with tetrabutylammonium carbonate in acetonitrile). Given the large number of important biological molecules possessing phosphorus such as oligonucleotides, phospholipids as well as phosphorylated proteins, sugars and steroids, this new labelling chemistry may provide an additional route to radiolabelling these biologically important compounds for use in PET. Copyright © 2005 John Wiley & Sons, Ltd.     

Synthesis of 2‐[(2‐chloro‐2′‐[18F]fluoroethyl)amino]‐2H‐1,3,2‐oxazaphosphorinane‐2‐oxide (18F‐fluorocyclophosphamide), a potential tracer for breast tumor prognostic imaging with PET

A fluorine‐18 labeled analog of the widely used chemotherapeutic agent cyclophosphamide was synthesized as a tracer for prognostic imaging with positron emission tomography. 2‐[(2‐Chloro‐2′‐[¹⁸F]fluoroethyl)amino]‐2H‐1,3,2‐oxazaphosphorinane‐2‐oxide (¹⁸F‐fluorocyclophosphamide), was prepared by direct halogen exchange reaction from the parent cyclophosphamide. In small‐scale syntheses, radiochemical yields of up to 4.9% and specific activities of 960 Ci/mmol were achieved in a total synthesis time of 60–75 min. The [¹⁸F]‐labeled cyclophosphamide analog with radioactive purity >99% and chemical purity >96% was suitable for in vivo (microPET imaging) and ex vivo studies of a murine model of human breast tumors. Copyright © 2005 John Wiley & Sons, Ltd.