磺胺甲恶唑的振动光谱和密度泛函理论研究

磺胺甲恶唑(Sulfamethoxazole, SMX)是一种磺胺类广谱抗生素.基于密度泛函理论(DFT)的B3LYP方法,在B3LYP/6-311++G (d, p)基组水平上对SMX初始构型进行结构优化,得出该分子最稳定结构构型.同时,给出了SMX的键长、键角和二面角等空间结构参数值,确定该分子空间构型为非平面结构.相同基组水平下进行频率计算,通过频率校正因子0.9630修正并绘制了SMX分子的红外光谱和拉曼光谱图.发现光谱谱段主要分布在3600-2800 cm^-1和1700-300 cm^-1频率段,并且理论计算值和实验测定值有较好吻合,表明DFT计算方法是可取和可信的.借助GaussView 6.0软件和计算得到的势能分布结果对频率范围内每一个振动模式进行了指认归属.此外,采用Multiwfn和VMD程序计算并分析SMX分子的静电势和前线分子轨道,预测了该分子的反应活性位点.该结果为SMX分子的振动光谱检测提供基础数据,为其结构鉴定提供技术参考.     

A green method using micellar system for determination of sulfonamides in soil

A green and simple method was developed for determination of sulfonamides (SAs) in soil samples. The procedure was based on the microwave-assisted extraction (MAE) of SAs from soil using non-ionic surfactant Triton X-114 as the extraction medium. Then sodium chloride was added into the MAE extract and the mixture was equilibrated for some time at high temperature. The analytes in the surfactant-rich phase were concentrated with the help of centrifugation and directly analyzed by high performance liquid chromatography with UV detection. None of potentially hazardous organic solvents was used in the whole sample preparation procedure. The significant variables for the performance of extraction and concentration were studied. The limits of detection of SAs obtained are in the range of 3.2-5.7 ng g⁻¹. The relative standard deviations of intra- and inter-day tests ranging from 3.5% to 7.7% and from 4.6% to 9.5% are obtained, respectively. This method was applied to the determination of SAs in some soil samples with different characteristics. The SAs recoveries obtained at fortified level of 100 ng g⁻¹ for these samples are in the range of 81.2-93.7%. The effect of ageing time of spiked soil samples on the SAs recoveries was examined by the proposed method and a method reported in the literature. The recoveries of SAs decreased when the ageing time changed from 1 day to 4 weeks.     

交替三线性分解二阶校正法结合高效液相色谱同时测定合成样与增效联磺片中的磺胺嘧啶及磺胺甲噁唑

利用交替三线性分解(ATLD)二阶校正法与高效液相色谱-二极管阵列检测器(HPLC-DAD)联用技术相结合,取色谱洗脱时间为1.0770～1.6237 min(间隔1/75 min),紫外吸收波长为230～316 nm(间隔2 nm),同时测定了在未知干扰物(磺胺(SN))共存下,合成样与增效联磺片中色谱及光谱皆严重重叠的磺胺嘧啶(SD)和磺胺甲噁唑(SM)的含量.当算法因子数N选定为3时,SD与SM的平均回收率分别为98.6±1.4%和100.7±3.7%; 当N=4时,SD与SM的平均回收率分别为101.2±2.1%和96.3±2.8%,增效联磺片中SD和SM的解析含量分别为195 mg/tablet和197 mg/tablet(N=3)以及198 mg/tablet,193 mg/tablet(N=4)(SD和SM药品标示含量均为200 mg/tablet),测定结果与实际结果相一致.     

Development and validation of a normal-phase high-performance thin layer chromatographic method for the analysis of sulfamethoxazole and trimethoprim in co-trimoxazole tablets

Pneumocystis carinii pneumonia (PCP) is often the ultimate mortal cause for immunocompromised individuals, such as HIV/AIDS patients. Currently, the most effective medicine for treatment and prophylaxis is co-trimoxazole, a synergistic combination of sulfamethoxazole (SMX) and trimethoprim (TMP). In order to ensure a continued availability of high quality co-trimoxazole tablets within resource-limited countries, Medicines Regulatory Authorities must perform quality control of these products. However, most pharmacopoeial methods are based on high-performance liquid chromatographic (HPLC) methods. Because of the lack of equipment, the Tanzania Food and Drugs Authority (TFDA) laboratory decided to develop and validate an alternative method of analysis based on the TLC technique with densitometric detection, for the routine quality control of co-trimoxazole tablets. SMX and TMP were separated on glass-backed silica gel 60 F₂₅₄ plates in a high-performance thin layer chromatograph (HPTLC). The mobile phase was comprised of toluene, ethylacetate and methanol (50:28.5:21.5, v:v:v). Detection wavelength was 254 nm. The R_f values were 0.30 and 0.61 for TMP and SMX, respectively. This method was validated for linearity, precision, trueness, specificity and robustness. Cochran's criterion test indicated homoscedasticity of variances for the calibration data. The F-tests for lack-of-fit indicated that straight lines were adequate to describe the relationship between spot areas and concentrations for each compound. The percentage relative standard deviations for repeatability and time-different precisions were 0.98 and 1.32, and 0.83 and 1.64 for SMX and TMP, respectively. Percentage recovery values were 99.00% ± 1.83 and 99.66% ± 1.21 for SMX and TMP, respectively. The method was found to be robust and was then successfully applied to analyze co-trimoxazole tablet samples.     

Solid contact PVC membrane electrodes based on neutral or charged carriers for the selective reading of anionic sulfamethoxazole and their application to the analysis of aquaculture water

Sulfamethoxazole (SMX) is among the antibiotics employed in aquaculture for prophylactic and therapeutic reasons. Environmental and food spread may be prevented by controlling its levels in several stages of fish farming. The present work proposes for this purpose new SMX selective electrodes for the potentiometric determination of this sulphonamide in water. The selective membranes were made of polyvinyl chloride (PVC) with tetraphenylporphyrin manganese (III) chloride or cyclodextrin-based acting as ionophores. 2-nitrophenyl octyl ether was employed as plasticizer and tetraoctylammonium, dimethyldioctadecylammonium bromide or potassium tetrakis (4-chlorophenyl) borate was used as anionic or cationic additive. The best analytical performance was reported for ISEs of tetraphenylporphyrin manganese (III) chloride with 50% mol of potassium tetrakis (4-chlorophenyl) borate compared to ionophore. Nersntian behaviour was observed from 4.0?×?10^?5 to 1.0?×?10^?2?mol/L (10.0 to 2500?µg/mL), and the limit of detection was 1.2?×?10^?5?mol/L (3.0?µg/mL). In general, the electrodes displayed steady potentials in the pH range of 6 to 9. Emf equilibrium was reached before 15?s in all concentration levels. The electrodes revealed good discriminating ability in environmental samples. The analytical application to contaminated waters showed recoveries from 96 to 106%.     

Simultaneous Spectrophotometric Determination of Sulfamethoxazole and Trimethoprim in Drugs.

Abstract

Two methods, namely first derivative and classical least squares methods are selected and applied for comparative purposes to analyze uv-spectra of the methanolic solutions of the cited components in synthetic binary mixtures and in a number of antibacterial pharmaceutical preparations, viz. three tablets and two syrups produced by Egyptian companies. The former technique is based on measuring the absorbances at zero-crossing wavelengths, 288 and 240 nm for the two drugs, respectively. Calibration curves are rectilinear in the range 4 –20 μg/ml of both components. The latter method is based on a pure standard full-spectra treatment ranged from 350 to 200 nm at 2 nm intervals to compute the concentration of unknowns. A statistical analysis of the results is reported.     

Simultaneous Multivariate Spectrophotometric Analysis of Binary and Ternary Mixtures of Sulfamethoxazole,Trimethoprim and Phenazopyridine in Tablets

ABSTRACT

The use of multivariate spectrophotometric calibration is reported for the analysis of tablets containing the antibiotics sulfamethoxazole and trimethoprim, and a combination of the former two drugs with the analgesic phenazopyridine. The resolution of these mixtures has been accomplished without prior separation, derivatisation or use of nonaqueous solvents, with the aid of partial least-squares (PLS-1) regression analysis of electronic absorption spectral data. The analytes have been simultaneously determined with high accuracy and precision, and with no interference from tablet excipients.     

Effects of Coordinating Solvents on the Supramolecular Assembling of Tectons arised from the Metallation of Sulfamethoxazole: Synthesis and Structural Characterization of Polymeric [Cd(sulfamethoxazolato)2(L)2]n {L = N,N‐dimethylformamide (DMF); Dimethyl Sulfoxide (DMSO)} and [Cd(sulfamethoxazolato)2(Py)2]n·n(Py)(Py =pyridine)

Cadmium acetate reacts with sulfamethoxazole (5‐methyl‐3‐isoxazolyl sulfanilamide) and with DMF / DMSO / pyridine to give the crystalline polymers [Cd(sulfamethoxazolato)₂(L₂)]_n {L = DMF ( 1 ), DMSO ( 2 )} and [Cd(sulfamethoxazolato)₂(Py)₂]_n·n(Py) ( 3 ). Complexes 1 , 2 and 3 confirm the tectonic character of the [Cd(sulfamethoxazolato)₂(L)₂] moieties and the remarkable ability of the {Cd(sulfamethoxazolato)₄} fragments to be non selectively stabilized by monodentate ligands. In the polymeric assemblies of the title complexes the cadmium(II) atoms are linked through sulfamethoxazolato anions which alternate in their coordination with the isoxazolic N‐atoms and the aromatic amino groups. The chains of vicinal rings build tunnels along the crystallographic c axis.     

Sulfamethoxazole-imprinted polymer for selective determination of sulfamethoxazole in tablets

A sulfamethoxazole (SMO)-imprinted polymer (MIP) was prepared in acetonitrile using the mixture of acrylamide and 4-vinylpyridine as functional monomers. The molecular recognition properties of the polymer was evaluated in both acetonitrile and aqueous acetonitrile mobile phases. SMO contents in two kinds of tablets were determined satisfactorily using the MIP packed HPLC column with aqueous mobile phase.     

白色体系化学计量学方法研究-MLR、Kalman滤波法、PCR、PLS和褶合光谱法的比较

对白色体系的化学计量学方法进行了研究,着重比较了多元线性回归法（MLR、Kalman滤波法（KF）、主成分回归法（PCR）、偏最小二乘法（PLS）和褶合光谱法等方法的原理,并用上述方法进行复方磺胺甲E唑片剂的不分离分析,表明间接校正法（PCR、PLS等）比直接校正法（MLR、KF等）得出的结果更准确。而以既包容了导数光谱法和正交函数法、又与PLS相结合的褶合光谱法结果最好。