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合成了新荧光试剂2,3,4-三羟基苯乙酮缩-2-羧基苯胺(TAFA)。详细研究了试剂与铜的荧光反应新体系的最佳适宜条件。在pH9.0的乙醇/水(3.5:6.5,V/V)溶液中,该试剂与铜离子形成稳定的络合物,组成比为1:1(金属:试剂),λex/em=422.4/561.6nm。所建立的铜的荧光分析方法的线性范围为0.5~120.0μg/L;检出限为0.26μg/L。方法成功地应用于矿泉水和水中痕量铜的测定。 相似文献
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合成了新型试剂3-对氟苯基-5.(2’-羧基苯偶氮)若丹宁,并经元素分析、IR确证了其结构。研究发现在pH=5.2时该试剂与痕量铋锄形成的螯合物可使试剂的荧光强度大大减弱,在λex/λem=305nm/404nm处有最大峰;其荧光猝灭值与铋的浓度在1.0-12μg/L范围内呈线性关系,检出限达0.26μ/L。建立了荧光光度法测定痕量铋的新方法。 相似文献
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双波长双指示物催化光度法测定水中痕量铜 总被引:1,自引:0,他引:1
研究了在pH5.5的Na2HPO4-NaH2PO4缓冲溶液介质中,痕量Cu(Ⅱ)催化过氧化氢氧化吖啶黄和酸性品红褪色的指示反应。通过测量450nm和540nm处,催化反应体系和非催化反应体系吸光度的变化,利用铜离子浓度与两波长处吸光度差值的和呈线性关系,建立了双波长双指示物催化光度法测定痕量铜的新方法。在最佳实验条件下,测定铜的线性范围为0.60~32μg/L,检出限为0.24μg/L。该方法操作简单,灵敏度高,选择性好,用于水样中痕量铜的测定,获得满意结果。 相似文献
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荧光红-曙红Y能量转移及荧光猝灭法测定痕量铜(Ⅱ)的研究 总被引:9,自引:0,他引:9
在λex/λem=404.7/550nm,乳化剂OP存在下,荧光红-曙红Y能够发生有效能量转移,使曙红Y荧光强度大大提高;在pH6.5~7.6的KH2PO4-NaOH缓冲溶液中,Cu(Ⅱ)与曙红Y和邻菲罗啉形成配合物,使曙红Y的荧光猝灭,从而建立了测定痕量铜的荧光分析新方法。铜含量在0~250μg/L范围内与曙红Y的荧光猝灭程度呈良好的线性关系。方法的检出限为0.82μg/L;测定100μg/L铜溶液,其RSD为4.6%(n=11);样品加标回收率为102.1%~105%。本法用于人发、茶叶和大米中痕量铜的测定,结果满意。 相似文献
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双-[4-(α-萘偶氮)-水杨醛]缩邻苯二胺的合成及其与铜的荧光熄灭反应 总被引:5,自引:0,他引:5
本文报道了一种新的含西佛碱的偶氮荧光试剂,双-[4-(a-萘偶氮)-水杨醛]缩邻苯二胺(BNASPD)的合成.试剂在435nm处有一强荧光峰.当有铜离子存在时,可与试剂形成稳定的配合物而使试剂的荧光熄灭.反应具有较高的灵敏度和选择性.利用此反应建立了一个荧光测定痕量铜的新方法,其检出限可达到1.0ngCu/mL.方法用于无机盐试剂及矿泉水中铜的测定,结果满意. 相似文献
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壳聚糖富集火焰原子吸收法测定水中痕量铜 总被引:8,自引:2,他引:8
采用壳聚糖修饰钨丝基质螺旋卷,直接浸入含有痕量铜的pH5.0的Brltton-Robinson缓冲溶液中,经电磁搅拌富集一定时间后,将其转移至空气/乙炔火焰燃烧器上,利用火焰原子吸收光谱法简便快速测定水中痕量铜。方法的线性范围为2—75μg/L;检出限为0.98μg/L。同一支钨丝螺旋卷重复涂敷壳聚糖富集Cu,RSD(n=6)为2.7%。 相似文献
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本文报道了新荧光试剂3-对甲苯基-5-(4’-硝基-2‘-羧基苯偶氮)-2-硫代-4-噻唑啉酮(MPNCPATTN)的合成。通过元素分析、红外光谱,核磁共振氢谱和质谱确证了其结构。在pH5.6时,它与铜(Ⅱ)形成稳定的荧光络合物,在λex/λem=308nm/403nm处产生强烈荧光,其荧光强度与铜(Ⅱ)的浓度在6.28×10-9~9.44×10-7mo1/L范围内呈线性关系,检测限为0.399μg/L的铜(Ⅱ)。测定了人发中的痕量铜,结果满意。 相似文献
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[formula: see text] The generation of (2-PyMe2Si)2CHLi was easily accomplished by the deprotonation of (2-PyMe2Si)2CH2 using n-BuLi in Et2O. Thus generated (2-PyMe2Si)2CHLi was found to react with a variety of aldehydes and ketones to give the corresponding vinylsilanes in extremely high yields with complete stereoselectivities. 相似文献
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3,4‐Bis(bromomethyl)thieno[2,3‐b]thiophene: Versatile Precursors for Novel Bis(triazolothiadiazines), Bis(quinoxalines), Bis(dihydrooxadiazoles), and Bis(dihydrothiadiazoles) 下载免费PDF全文
Osama M. Sayed Ahmed E. M. Mekky Ahmad M. Farag Ahmed H. M. Elwahy 《Journal of heterocyclic chemistry》2016,53(4):1113-1120
A synthesis of novel bis(triazolothiadiazines) 11 , 12 , 13 , 14 , bis(quinoxalines) 16 and 17 , bis(thiadiazoles) 24 and 25 , and bis(oxadiazole) 31 , which are linked to the thieno[2,3‐b]thiophene core via phenoxymethyl group, was reported. Thus, reaction of the bis(α‐bromoketones) 6 and 7 with the corresponding 4‐amino‐3‐mercapto‐1,2,4‐triazole derivatives 8 , 9 , 10 in ethanol–DMF mixture in the presence of a few drops of triethylamine as a catalyst under reflux afforded the novel bis(5,6‐dihydro‐s‐triazolo[3,4‐b]thiadiazines) 11 , 12 , 13 , 14 in 60–72% yields. The bis(quinoxalines) 16 and 17 were also synthesized as a sole product in high yields by the reaction of 6 and 7 with o‐phenylenediamine 15 in refluxing acetonitrile in the presence of piperidine as a catalyst. Cyclization of the bis(aldehyde thiosemicarbazones) 20 and 21 with acetic anhydride afforded the corresponding bis(4,5‐dihydro‐1,3,4‐thiadiazolyl) derivatives 24 and 25 in good yield. Bis(5‐phenyl‐2,3‐dihydro‐1,3,4‐oxadiazole) derivative 31 could be obtained in 67% yield by cyclization of the appropriate bis(N‐phenylhydrazone) 29 in refluxing acetic anhydride for 3 h. 相似文献
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The double Kabachnik–Fields condensation of primary amines with 2 equivalents of the other reagents (formaldehyde and a >P(O)H species, such as dialkyl phosphites, diphenylphosphine oxide, as well as the related dioxaphosphorine and oxaphosphorine derivatives) carried out under microwave conditions afforded the title products in 79–94% yields. The bis(phosphinoxidomethyl)amines were converted, after double deoxygenation, to the corresponding ring platinum complexes.
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