荧光分光光度法测定水中痕量钴和镍

试验合成了一种荧光试剂对-氨-苯基卟啉(TAPP),该试剂与钴(Ⅱ)离子和镍(Ⅱ)离子反应发生荧光淬灭,据此试验了以其为探针测定痕量钴(Ⅱ)和镍(Ⅱ)的荧光分光光度法。在pH7.2的Tris-盐酸缓冲介质中,在一定量的十二烷基硫酸钠(SDS)存在下,通过测定样品溶液和空白溶液在激发波长392 nm和发射波长516 nm处的发射荧光强度F_s及F_0,计算得反应液荧光强度减弱程度△F,其结果表明:△F与钴(Ⅱ)和镍(Ⅱ)的浓度均在2.0×10~(-7)～1.0×10~(-5)mol·L~(-1)范围内呈线性关系,方法的检出限(3S/N)分别为2.0×10~(-8)mol·L~(-1)和4.0×10~(-8)mol·L~(-1)。此方法用于自然水体和污水中钴(Ⅱ)和镍(Ⅱ)的测定,回收率分别在97.0%～108.5%和97.0%～106.5%之间。     

基于氨基化碳量子点荧光增强测定氨苄青霉素

采用水热法制备碳量子点,通过碳量子点与氨水反应使其表面氨基化,氨苄青霉素与氨基化碳量子点作用后,使其荧光显著增强,由此建立测定药物中氨苄青霉素的荧光光度法。在比色管中依次加入0.016mol·L~(-1)氨基化碳量子点溶液1.00mL和样品溶液0.45mL,pH 7.0三酸缓冲溶液1mL,用水定容至5mL,室温下反应30min后,在激发波长340nm、发射波长433nm处测量溶液相对荧光强度(F/F0,F、F0分别为加入与不加入氨基化碳量子点时体系的荧光强度)。氨苄青霉素质量浓度在2.0×10~(-6)~9.0×10~(-5) mol·L~(-1)内与体系的相对荧光强度呈线性关系,检出限(3S/N)为1.2×10~(-6) mol·L~(-1)。加标回收率为99.0%~109%,测定值的相对标准偏差(n=5)小于2.0%。     

荧光探针N-9-吖啶-α-氨基乙酸的合成及荧光分光光度法测定环境水样中痕量铜

对荧光探针N-9-吖啶-α-氨基乙酸的合成方法作了改进,使偶氮化反应时间由7 h缩短为3 h,产率由78.9%提高至85.2%.此试剂与铜(Ⅱ)反应使其荧光猝灭,并据此提出了以此试剂为探针的痕量铜的荧光光度测定法.在pH 7.0的缓冲介质中,在一定量的乙醇存在下,铜(Ⅱ)与荧光探针反应,通过测定样品溶液和空白溶液在激发波长(λex)262.0 nm和发射波长(λem)456.0 nm的荧光强度FA和FB,计算得反应液荧光强度猝灭程度△F,其荧光强度的猝灭程度与铜(Ⅱ)质量浓度在0.20～600.0 μg·L-1范围内呈线性关系,方法的检出限(3a/b)为0.04μg·L-1.按此方法分析了3个环境水样,测得其铜量值的相对标准偏差(n=6)均小于2.5%,回收率在96.0%～102.0%之间.     

高效液相色谱-质谱法测定青藏高原植物和土壤样品中氨基酸

提出了高效液相色谱-质谱法测定青藏高原植物和土壤样品中氨基酸的含量。样品中氨基酸经6mol·L~(-1)盐酸溶液提取,加入衍生试剂1,2-苯并-3,4-二氢咔唑-9-乙基氯甲酸酯(BCEOC)进行衍生化反应,衍生化产物经Hypersil BDS C_(18)(4.6mm×200mm,5μm)色谱柱分离,于激发波长(λ_(ex))333 nm和发射波长(λ_(em))390nm进行荧光检测定量,用质谱法定性。色谱分离中采用不同体积比的乙腈与水的混合溶液梯度洗脱,在质谱检测中采用电喷雾离子源正离子模式。方法的检出限(3S/N)为6.3×10~(-15)～1.8×10~(-13)mol之间。以土壤样品为基体,加入20种氨基酸标准作回收试验,测得回收率在89.0%～107.0%之间。     

双臂罗丹明类荧光探针应用于Hg~(2+)的识别

合成了一种基于罗丹明衍生物的荧光探针F1,用于识别Hg~(2+)。当在乙腈(1+1)溶液中加入1倍当量(10μmol·L~(-1))的Hg~(2+)时,探针F1在波长561nm处出现明显的吸收峰,其荧光强度(λ_(ex)=550nm,λ_(em)=580nm)增加7.5倍,溶液由无色变为粉红色,这是由于Hg~(2+)和罗丹明螺内酰胺螯合引发开环所致。其他常见的金属离子对探针F1识别Hg~(2+)不产生干扰。在较宽的酸度范围内,Hg~(2+)浓度在0.2~8μmol·L~(-1)内与荧光强度呈线性关系,检出限(3σ/s)为0.15μmol·L~(-1)。     

茜素红荧光探针的设计及对化妆品中Pb~(2+)的检测

在pH 6.2的弱酸性介质中,茜素红与铅反应生成荧光络合物,且荧光强度与铅离子的浓度在一定范围内呈线性关系,由此建立了简单快速测定化妆品中的铅含量的新方法。实验探讨了反应体系的pH、表面活性剂、缓冲溶液、显色剂用量、反应时间、反应温度对体系荧光强度的影响。以激发和发射波长λ_(ex)/λ_(em)=510 nm/620 nm测定铅离子浓度,线性范围为8×10~(-8)~1.2×10~(-5)mol/L,R~2=0.9983,检出限为1.04×10~(-8) mol/L。方法可用于快速测定化妆品中的铅含量。     

催化动力学荧光光度法测定痕量钇(Ⅲ)

研究发现痕量钇(Ⅲ)对过氧化氢氧化瑞士色素反应有很好的催化作用,据此建立了催化动力学荧光光度法测定痕量钇(Ⅲ)的方法。本文考察了荧光体系的光谱特征,研究了试剂用量、酸度、反应温度和反应时间以及共存离子对体系荧光强度的影响,并确定了最佳反应条件。结果表明,体系的最大激发波长(λex)和最大发射波长(λem)分别为512和538 nm。最佳反应条件如下:6.0×10~(-5)mol·L~(-1)瑞氏色素溶液的用量为1.0m L;5%的H_2O_2的用量为0.8 mL;反应温度为55℃;反应时间为20 min。方法的线性范围为0.2~1.8μg·m L~(-1),检出限为3.97×10~(-3)μg·m L~(-1),可用于样品中痕量钇的测定,加标回收率在92.5%~104.3%之间。     

煤基碳量子点荧光猝灭法测定注射液和牛奶样品中卡那霉素

制备了煤基碳量子点(CQDs),此纳米材料具有较高的荧光强度,在激发波长(λex)为370nm时,其发射波长(λem)为495nm。卡那霉素(KANA)对CQDs的荧光具有猝灭效应,并测得其荧光强度的猝灭程序与KANA的浓度在5.0～140.0μmol·L~(-1)之间呈线性关系,KANA的检出限(3s/k)为1.0μmol·L~(-1)。根据进一步试验提出了KANA注射液及牛奶中KANA含量的荧光猝灭测定法。CQDs与KANA反应的最佳条件为:①反应介质为pH 7.5三(羟甲基)氨基甲烷(Tris-HCl)缓冲溶液;②CQDs溶液的加入量为0.5mL;③反应时间为10min。两种样品溶液的制备方法如下:①取KANA注射液5支,混匀后分取0.1mL,加水定容至100.0mL,经滤膜过滤,取滤液作为测定溶液;②取牛奶10.0g,加无水乙醇定容至50.0mL,静置30min后离心,取其上清液为测定溶液。测定时取测定液适量,加入Tris-HCl缓冲溶液和CQDs溶液各0.5mL,加水至5.0mL,按上述条件测定其荧光强度(F),同时测定空白溶液的荧光强度(F0)。经回收试验,测得其回收率在97.0%～104%之间,测定值的相对标准偏差(n=6)在1.2%～2.6%之间。经用高效液相色谱法作比对,两种方法所测得的结果相符。测得KANA注射液样品的KANA测定值为99.6g·L~(-1),与其标示值(100g·L~(-1))相符。     

新型荧光试剂1-(8-喹啉)-3-(3,5-二溴-2-吡啶)-三氮烯的合成及其应用

将具有荧光特性的杂环8-氨基喹啉和吡啶类试剂结合,并引入三氮烯结构,合成了新型荧光试剂1-(8-喹啉)-3-(3,5-二溴-2-吡啶)-三氮烯(QBPyT)。其结构经元素分析、红外光谱、核磁共振波谱证实。研究结果表明,在pH 9.5硼酸-氢氧化钠缓冲溶液的介质存在下,该试剂在λex/λem=248nm/496nm处产生强荧光,并且能与铅(Ⅱ)形成配合物从而使荧光增强。据此建立了三氮烯测定铅(Ⅱ)的新型荧光分析法。铅的浓度在5.0×10-7～1.2×10-5 mol.L范围内与其荧光强度呈线性关系,检出限(3S/N)为9.5×10-8 mol.L。将其应用于水样中铅(Ⅱ)的测定,测得回收率在92.6%～94.0%之间,测定值的相对标准偏差(n=5)小于3.5%。     

CdTe量子点荧光猝灭法测定甲醛

采用一步水热法合成了水溶性N-乙酰-L-半胱氨酸修饰的碲化镉量子点(NACCdTe),基于甲醛对该量子点的荧光猝灭作用,建立了测定甲醛的荧光光谱法。在7.5×10~(-8) mol·L~(-1) NAC-CdTe-0.01mol·L~(-1) Tris-HCl(pH 6.0)体系中加入不同质量浓度的甲醛溶液,反应10min后,以400nm为激发波长,于567nm处测量体系的荧光强度(I)。甲醛的质量浓度在5.0×10~(-6)~1.0×10~(-1) g·L~(-1)内与I_0/I(I_0为不加甲醛时体系的荧光强度)值呈线性关系,检出限(3s/k)为1.3×10~(-6)g·L~(-1)。方法用于测定水样中的甲醛,测定结果与乙酰丙酮分光光度法的测定结果相符,加标回收率在98.0%~102%之间,测定值的相对标准偏差(n=5)在1.4%~4.1%之间。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

解决能源问题的新途径——光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.