火焰原子吸收光谱法测定土壤中的铜

土壤样品经HNO3-HF驱尽二氧化硅并完全溶解后,使用火焰原子吸收分光光度计进行测定。该方法的最低检出限为0.016mg·L-1,检出下限为0.16mg·L-1,精密度为0.62%—1.01%,铜元素的加标回收率为98.0%—99.2%。本方法测定国家质控标样,结果吻合。     

分光光度法检测废水中的间苯二酚

在盐酸介质中 ,果糖与间苯二酚反应生成红色化合物 ,其最大吸收波长为 4 0 3nm,由此建立了一种测定间苯二酚的方法 ,测定范围为 0— 2 0 0 mg·L-1,检出限为 0 .38mg· L-1。方法用于实验室废水中的间苯二酚测定 ,结果令人满意     

荷移荧光光谱法测定加替沙星

研究了加替沙星(GFLX) 与电子受体四氯对苯醌(TCBQ)之间的荷移反应,建立了测定加替沙星的新方法。实验结果表明,在甲醇-水介质中于45 ℃水浴恒温20 min,GFLX与TCBQ可形成稳定的1∶1电荷转移络合物,其荧光发射强度较GFLX本身有显著的增强。在0.19～5.6 mg·L-1 浓度范围内,荧光强度与GFLX浓度呈良好的线性关系,检出限为0.005 6 mg·L-1。用于药物制剂中GFLX的含量测定,其回收率为101.1%～103.9%;标准偏差为1.0%～1.9%。同时建立了测定尿样中GFLX的荷移同步荧光光谱法,GFLX浓度在0.023～3.4 mg·L-1范围内与荧光强度呈良好的线性关系,检出限为0.003 4 mg·L-1。用本方法测定尿液中的GFLX,结果与文献值基本一致,回收率为93.9%～101.0%;标准偏差为1.0 %～1.7%。     

流动注射化学发光法测定利巴韦林

在碱性介质中 ,N -溴代丁二酰亚胺 (NBS)氧化鲁米诺产生化学发光 ,利巴韦林对该化学发光体系具有显著的抑制作用 ,据此建立了流动注射化学发光测定利巴韦林的新方法。利巴韦林浓度在 7.4× 1 0 -3 —7.4× 1 0 -2 mg· m L-1 范围内 ,相对化学发光强度Δ I与浓度的对数呈良好的线性关系 ,方法的检出限 (3σ)为 1 .5 0× 1 0 -3 mg· m L-1 ,相对标准偏差 (C=7.4× 1 0 -3 mg· m L-1 ,n=1 1 )为 4 .5 %,该方法已用于注射液中利巴韦林含量的测定 ,结果令人满意。     

吖啶橙-罗丹明B二聚体能量转移体系在DNA测定中的应用及机理研究

首次研究了吖啶橙 罗丹明B二聚体能量转移体系作为荧光探针用于DNA的测定 ,并对其机理进行了探讨。用于鲱鱼精DNA和小牛胸腺DNA的测定 ,线性范围分别为 0 33～ 1 33mg·L- 1 ,0 33～ 3 33mg·L- 1 ,检测限分别为 1 6 3× 10 - 3mg·L- 1 ,1 5 2× 10 - 3mg·L- 1 。对 1 0 0mg·L- 1 鲱鱼精DNA和小牛胸腺DNA的测定 ,相对标准偏差分别为 2 4 %和 2 0 %。     

结晶紫分光光度法测定双酚A的含量

在酸性介质中,双酚A对羟基自由基氧化结晶紫的反应具有抑制作用,据此建立了分光光度法测定痕量双酚A的新方法。在最佳实验条件下测量结晶紫580nm处的吸光度变化值,得到方法的线性范围是0.015—0.25μg/mL,相关系数为0.9994,检出限和定量下限分别为3.3、11.0ng/mL。应用此法测定了6种样品中双酚A的含量,回收率在91%—118%之间,相对标准偏差为1.3%—6.8%。该方法简便快速,结果稳定准确。     

微波消解-ICP-AES测定煤制油催化剂中的杂质钠

采用微波消解、全谱直读电感耦合等离子体 -原子发射光谱法 (ICP- AES)测定煤制油催化剂中的杂质金属钠含量 ,方法检出限为 0 .0 3mg·L-1 ,回收率在 96 %— 1 0 3%之间 ,相对标准偏差为 1 .5 4%,测定结果令人满意。     

阿莫西林的荷移光谱测定方法研究

在丙酮介质中阿莫西林与 7,7,8,8-四氰基对二次甲基苯醌 (TCNQ)荷移反应 ,形成 1∶ 1络合物 ,在74 4nm和 84 5 nm处有较强光吸收 ,表观摩尔吸光系数分别为 1.2× 10 4L· mol-1· cm-1和 1.8× 10 4L·mol-1· cm-1,阿莫西林的浓度在 10— 15 0 mg· L-1范围内符合比耳定律。在乙醇介质中 ,阿莫西林与对苯醌 (p- BQ)反应 ,形成 1∶ 1络合物 ,最大吸收波长为 4 80 nm,表观摩尔吸光系数为 1.92× 10 3 L· mol-1·cm-1。阿莫西林的浓度在 2 0— 2 0 0 mg·L-1范围内符合比耳定律。两种方法相对标准偏差分别为 1.2 %和1.5 % (n=8) ,用于测定阿莫西林制剂的含量 ,结果与标准方法一致。     

茜素分光光度法测定磷霉素钠

在乙醇体系中,磷霉素钠与茜素发生反应,生成稳定的1∶1的络合物,溶液颜色发生明显改变,其最大吸收波长为545nm,磷霉素钠的浓度在1.4—60mg·L-1范围内遵守比耳定律,表观摩尔吸光系数ε=3.47×103L·mol-1.cm-1,基于以上反应,本方法测定药物制剂含量与文献方法一致,回收率在99.6%—100.5%之间,结果满意。     

酸性棕SR分光光度法测定血清白蛋白

在Britton-Robinson酸性缓冲溶液中,加入非离子表面活性剂阿拉伯胶,能使酸性棕SR(ASR)与血清白蛋白形成复合物,最大吸收波长为610 nm,比ASR红移165 nm。采用分光光度法研究了该结合反应的最佳条件,并据此建立了一种测定血清蛋白的新方法。λ=610 nm时,ε_BSA=6.23×104 L·mol-1·cm-1,ε_HSA=7.23×104 L·mol-1·cm-1;牛血清白蛋白(BSA)在0～91.0 mg·L-1,人血清白蛋白(HSA)在0～95.2 mg·L-1范围内服从比尔定律。检出限分别为BSA：5.72 mg·L-1,HSA：5.15 mg·L-1。对6个人血清蛋白总量平行6次测定,相对标准偏差1.8%～4.4%,回收率93.6%～109.1%,并对5只小白鼠的血清蛋白总量进行了测定。     

基于密度泛函理论的外电场下双酚A型环氧树脂分子的结构及特性

采用密度泛函m062x的方法在6-31g(d)基组上对双酚A型环氧树脂分子进行优化得到了它的稳定结构,并且研究了不同外电场(0-0.013 a.u., 1 a.u.=5.142×10~(11) V/m)作用下双酚A型环氧树脂分子的分子结构、电偶极矩和分子总能量,偶极矩、极化率、前线轨道的能级和成分,原子之间的键能和红外光谱的变化.研究表明:随着外加电场的增大,双酚A型环氧树脂分子从倒V型结构逐渐变成线性结构,总能量降低,偶极矩和极化率都升高,且双酚A型环氧树脂分子的稳定性随着外加电场的增大而降低;最高占据轨道能级随着外加电场的增大而增大,沿逆电场方向分子链端表现出亲核反应活性,最低空轨道能级随着外加电场的增大而减小,沿电场方向分子链端表现出亲电反应;位于分子两端环氧基团上的C-C,C-O容易发生断裂,进而破环了双酚A型环氧树脂分子的稳定性;分子红外光谱在高频区的吸收峰出现了明显的红移现象.     

Phototransformation of Bisphenol a in Water in the Presence of Materials Based on Ultrafine Polypropylene Fibers

Russian Physics Journal - The effect of UV radiation on the efficiency of bisphenol A (BPA) phototransformation in water in the presence of polypropylene nonwoven material based on ultrafine fibers...     

Fluorimetric Method Based on Diazotization-Coupling Reaction for Determination of Clenbuterol

A novel fluorimetric method based on diazotization-coupling reaction (DCR) for the determination of clenbuterol is described. In acidic solution, clenbuterol was first diazotized with sodium nitrite, followed by coupling with bisphenol A to produce an azo-compound in NH₃- NH₄Cl buffer. It has found the diazotized clenbuterol- bisphenol A- NH₃- NH₄Cl (DCBN) system has strong fluorescence efficiency compare with the bisphenol A solution. There is a linear relationship between the increased intensity of the fluorescence emission spectra (λ_ex/λ_em?=?276 nm/306 nm) and the concentration of clenbuterol. The effects of the amount of sodium nitrite, diazo reaction time, the amount of bisphenol A, coupling reaction time and coupling reaction temperature have been examined. Under the optional conditions, clenbuterol can be determined over the concentration range of 0.02 to 2.0 μg mL^?1 with a correlation coefficient of 0.9953. The detection limit is 0.01 μg mL^?1 at a signal-to-noise ratio of 3. The relative standard deviation (RSD) for 11 repetitive determinations of 0.9 μg mL^?1 clenbuterol is 0.22 %. The utility of this method was demonstrated by determining clenbuterol in meat samples.     

Ultrasonic cavitation applied to the treatment of bisphenol A. Effect of sonochemical parameters and analysis of BPA by-products

Bisphenol A (BPA), a chemical compound largely used in the plastics industry, can end up in aquatic systems, which it disturbs by its endocrine disrupting effect (EDE). This study investigated the BPA degradation upon ultrasonic action under different experimental conditions. The effect of saturating gas (oxygen, argon and air), BPA concentration (0.15-460 micromol L(-1)), ultrasonic frequency (300-800 kHz) and power (20-80 W) were evaluated. For a 118 micromol L(-1)-BPA solution, with the best performance obtained at 300 kHz, 80 W, with oxygen as saturating gas. In these conditions, BPA can be readily eliminated by the ultrasound process (approximately 90 min). However, even after long ultrasound irradiation times (9 h), more than 50% of chemical oxygen demand (COD) and 80% of total organic carbon (TOC) remained in the solution. Analyses of intermediates using HPLC-MS investigation identified several products: monohydroxylated bisphenol A, 4-isopropenylphenol, quinone of monohydroxylated bisphenol A, dihydroxylated bisphenol A, quinone of dihydroxylated bisphenol A, monohydroxylated-4-isopropenylphenol and 4-hydroxyacetophenone. The presence of these hydroxylated aromatic structures showed that the main ultrasonic BPA degradation pathway is related to the reaction of BPA with the *OH radical. After 2h, these early products were converted into biodegradable aliphatic acids.     

A facile method for grafting of bisphenol A imprinted polymer shells onto poly(divinylbenzene) microspheres through precipitation polymerization

Core-shell structured polymers are usually prepared by “grafting to” or “grafting from” techniques, wherein polymer supports were first modified by vinyl bonds or initiators. Success can be immediate, but more often a learning curve needs to be traversed. In this paper, direct grafting bisphenol A imprinted polymer onto poly(divinylbenzene) microspheres through precipitation polymerization is introduced. The obtained microspheres were characterized by SEM, TEM, FTIR and BET. Firstly, mono-disperse poly(divinylbenzene) microspheres of 3 μm in size were prepared by precipitation polymerization. The solvent for grafting was then optimized and it was found that the mixtures of toluene and acetonitrile (30/70, v/v) were ideal choice from the image and structure analysis of the shells. Shells of different thickness (270-840 nm), depending on the concentrations of monomers in the precursor, were then directly grafted to the microspheres by a reactive, entropic capture mechanism. The recognition ability of the microspheres was evaluated by solid-phase extraction and clear selectivity showed toward bisphenol A. The leak of bisphenol A was not found after extraction and thus these core-shell structured imprinted polymers are believed to have potential applications in trace analysis area.     

二甲氧基蒽－蒽醌体系分子内激发态复合物形成的结构条件与溶剂效应

本文报道了电子给体二甲氧基蒽（ＤＭＡ）和电子受体蒽醌（ＡＱ）以双酚Ａ（ＢＡ）和对苯二酚（ＯＰ）连接起来的双发色团分子的合成和光谱性质研究，并根据光谱数据和荧光光谱，讨论了激发态复合物形成的结构因素和溶剂效应．     

二甲氧基蒽－蒽醌体系分子内激发态复合物形成的结构条件与溶剂效应

本文报道了电子给体二甲氧基蒽(DMA)和电子受体蒽醌(AQ)以双酚A(BA)和对苯二酚(OP)连接起来的双发色团分子的合成和光谱性质研究,并根据光谱数据和荧光光谱,讨论了激发态复合物形成的结构因素和溶剂效应。     

Participation of Ionic Forms in Bisphenol Phototransformation Under Sunlight Exposure

Russian Physics Journal - The absorption and fluorescence spectra of charged anionic and cationic forms of bisphenol A (BPA) have been studied. The nature of electronically excited states and the...     

Simple and Sensitive Synchronous- Fluorescence Method for the Determination of Trace Bisphenol S Based on its Inhibitory Effect on the Fluorescence Quenching Reaction of Rhodamine B

An inhibitory kinetic fluorimetric method is reported for the determination of trace bisphenol S (BPS). The proposed method is based on the inhibitory effect of BPS on the fluorescence quenching of rhodamine B (RhB) caused by potassium bromate in a dilute phosphoric acid medium. Under the optimal conditions of the experiment, the detection limit for BPS was 0.021 mg/L, and the linear range of determination was from 0.035 mg/L to 0.750 mg/L. The relative standard deviations of 11 measurements for 0.20 mg/L and 0.40 mg/L BPS solutions were 2.74 % and 1.87 %, respectively. The method was successfully applied to the determination of bisphenol S derived from commercially available plastic film samples in hot water. A possible reaction mechanism of the inhibitory effect of BPS on the fluorescence quenching of RhB was proposed.     

Mechanism of O2-accelerated sonolysis of bisphenol A

The effects of dissolved gases on the sonochemical degradation of bisphenol A (BPA) were studied at a frequency of 500 kHz. BPA degradation rate increased in the order O(2)>Ar>air>N(2). The rate constant for oxygen (2.6 h(-1)) was approximately two fold higher than that for argon (1.2 h(-1)). A primary intermediate (2,3-dihydro-2-methylbenzofuran), a typical intermediate of BPA formed during attack by OH radicals, was detected only in the presence of oxygen, revealing that a different reaction path was responsible for the enhancement of decomposition.