Raman spectral analysis of phenoxyacetic acid and some chloro substituted phenoxyacetic acids

Raman spectra of phenoxyacetic acid and chlorine substituted phenoxyacetic acids viz., o-chlorophenoxyacetic acid, p-chlorophenoxyacetic acid and 2,6-dichlorophenoxyacetic acid have been analysed with the aid of abinitio theoretical calculations. The effect of chlorine substituents on the Raman spectra of phenoxyacetic acid have also been analysed by considering some important vibrational modes.     

苯氧乙酸化合物的质谱碎裂

对12种苯氧乙酸化合物的电子轰击质谱进行了系统研究,总结了相应的碎裂规律,讨论了取代基的影响,同时利用串联质谱的低能碰撞诱导解离（CID）、联动扫描（B^2/E)和同位素标记技术研究了硝基苯氧乙酸异构体的主要碎片离子的单分子质变碎裂,并对其形成过程进行了探讨。     

Plain Thin-layer Chromatography of Some Herbicides and Related Compounds on Admixture of Barium Sulfate and Calcium Sulphate in Mixed Solvents

Abstract

Some carboxylic herbicides and plant growth regulators such as benzoic acid, 4-chlorophenoxyacetic acid, cinnamic acid, 2,4-D, indole-3-acetic acid, indolepropionic acid, α-naphthalleneacetic acid, β-naphthal eneacetic acid, β-naphthoxyacetic acid, phenoxyacetic acid, TCA and 2,4,5-T have been separated on BaSO₄-CaSO₄ (1:1) coatings in mixed solvent systems.

Quantitative separations of indole-3-acetic acid (100 μg) from 50–100 μg of benzoic acid, α-naphthaleneacetic acid and 2,4,5-T have been carried out successfully.     

苯氧乙酸烯丙酯的合成

对苯酚和氯乙酸的Williamson反应加以改进,使苯氧乙酸的收率达到95．4％。并以苯氧乙酸和烯丙醇为原料,活性碳负载磷钨酸为催化剂,合成了苯氧乙酸烯丙酯。考察了两个反应的主要影响因素。     

Sequential Thin-Layer Chromatography of 2,4-D and Related Compounds

Abstract

Separations and identification of carboxylic herbicidal substances such as 2,4-dichlorophenoxyacetic acid, trichloroacetic acid, 2,4,5-trichlorophenoxyacetic acid and plant growth regulators such as benzoic acid, cinnamic acid, indole-3-acetic acid, β-naphthaleneacetic acid, β-naphthoxyacetic acid, phenoxyacetic acid have been made by sequential thin-layer chromatography on calcium sulphate layer with acetone, benzene, carbon tetrachloride, chloroform, ethyl acetate, dioxan, propanol as solvents and bromophenol blue as detector.     

Dispersive liquid–liquid microextraction combined with online preconcentration MEKC for the determination of some phenoxyacetic acids in drinking water

A fast and simple technique composed of dispersive liquid–liquid microextraction (DLLME) and online preconcentration MEKC with diode array detection was developed for the determination of four phenoxyacetic acids, 2,4,5‐trichlorophenoxyacetic acid, 2,4‐dichlorophenoxyacetic acid, 2,6‐dichlorophenoxyacetic acid, and 4‐chlorophenoxyacetic acid, in drinking water. The four phenoxyacetic acids were separated in reversed‐migration MEKC to the baseline. About 145‐fold increases in detection sensitivity were observed with online concentration strategy, compared with standard hydrodynamic injection (5 s at 25 mbar pressure). LODs ranged from 0.002 to 0.005 mg/L using only the online preconcentration procedures without any offline concentration of the extract. A DLLME procedure was used in combination with the proposed online preconcentration strategies, which achieved the determination of analytes at limits of quantification ranging from 0.2 to 0.5 μg/kg, which is far lower than the maximum residue limits established by China. The satisfactory recoveries obtained by DLMME spiked at two levels ranged from 67.2 to 99.4% with RSD <15%, making this proposed method suitable for the determination of phenoxyacetic acids in water samples.     

Synthesis of Nitrogen-Containing Phenoxyacetic Acid Derivatives

Nitrogen-containing phenoxyacetic acid derivatives were synthesized by reactions of substituted phenoxyacetic acids with amines, urea, and ethyl carbamate.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 557–561.Original Russian Text Copyright © 2005 by Yamansarova, Kukovinets, Zainullin, Galin, Abdullin.     

Synthesis of mono-, bis-spiro- and dispiro-β-lactams and evaluation of their antimalarial activities

Some new mono-, bis-spiro- and dispiro-β-lactams have been synthesized from imines derived from 9H-fluoren-9-one and a ketene derived from 9H-xanthene-9-carboxylic acid or phenoxyacetic acid by a [2+2] cycloaddition reaction in good to excellent yields varying from 45 to 83%. The biological activity of these monocyclic β-lactams was successfully investigated against Plasmodium falciparum K14 resistant strain with excellent EC₅₀ values up to 5 μM.     

新型含芳氧乙酸酯基三唑酮类化合物的合成及生物活性研究

通过芳氧乙酸与2-溴-4,4-二甲基-1-(1H-1,2,4-三唑-1-基)-3-戊酮反应, 合成了14个新型含芳氧乙酸酯基三唑酮类化合物. 所有化合物均经核磁、元素分析确证, 部分化合物进行了红外和质谱的测定. 生物活性测试表明部分化合物具有良好的生物活性.     

Analysis of phenoxyacetic acid herbicides as biomarkers in human urine using liquid chromatography/triple quadrupole mass spectrometry

Phenoxyacetic acids are widely used herbicides. The toxicity of phenoxyacetic acids is debated, but high-level exposure has been shown to be hepatotoxic as well as nephrotoxic in animal studies. An inter-species difference in toxic effects has been found, with dogs particularly susceptible. In this study a method using liquid chromatography/triple quadrupole mass spectrometry (LC/MS/MS) is described for the analysis of 4-chloro-2-methylphenoxyacetic acid (MCPA), and its metabolite 4-chloro-2-hydroxymethylphenoxyacetic acid (HMCPA), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in human urine. The urine samples were treated by acid hydrolysis to degrade possible conjugations. The sample preparation was performed using solid-phase extraction. Analysis was carried out using selected reaction monitoring (SRM) in the negative ion mode. Quantification of the phenoxyacetic acids was performed using [(2)H(3)]-labeled MCPA and 2,4-D as internal standards. The method was linear in the range 0.05-310 ng/mL urine and has a within-run precision of 2-5%. The between-run precision in lower concentration ranges was between 6-15% and between 2-8% in higher concentration ranges. The limit of detection was determined to 0.05 ng/mL. The metabolites in urine were found to be stable during storage at -20 degrees C. To validate the phenoxyacetic acids as biomarkers of exposure, the method was applied in a human experimental oral exposure to MCPA, 2,4-D and 2,4,5-T. Two healthy volunteers received 200 microg of each phenoxyacetic acid in a single oral dose followed by urine sampling for 72 h post-exposure. After exposure, between 90 and 101% of the dose was recovered in the urine. In the female subject, 23%, and in the male subject 17%, of MCPA was excreted as HMCPA.     

有抗病毒活性的苯并咪唑苯氧乙酸乳糖酯的催化合成

苯并咪唑及其衍生物在应用上有许多报道,是广泛使用的驱虫剂、杀真菌剂、植物病毒抑制剂、农用杀菌剂（如多菌灵）,作为医药也有许多报道。芳氧羧酸类化合物是医药、农药、染料的中间体,其中一些还具有杀虫、杀菌、除草和植物激素等多方面的生物活性。     

Solid‐phase extraction of phenoxyacetic acid herbicides in complex samples with a zirconium(IV)‐based metal–organic framework

A zirconium(IV)‐based metal–organic framework material (MOF‐808) has been synthesized in a simple way and used for the extraction of phenoxyacetic acids in complex samples. The material has good thermal and chemical stability, large specific surface area (905.36 m²/g), and high pore size (22.18 Å). Besides, it contains a large amount of Zr‐O groups, easy‐to‐form Zr‐O‐H bond with carboxyl groups of phenoxyacetic acids, and possesses biphenyl skeleton structure, easy to interact with compounds through π‐π and hydrophobic interactions. These characteristics make the material very suitable for the extraction of certain compounds with a high extraction efficiency and excellent selectivity. The extraction conditions were optimized, and then an analytical method was successfully established and applied for analysis of actual samples. The solid‐phase extraction method based on prepared material had a wide linear range of 0.2–250 μg/L and a low detection limit of 0.1–0.5 μg/L for four phenoxyacetic acid compounds including 2,4‐dichlorophenoxyacetic acid, 2‐(2,4‐dichlorophenoxy) propionic acid, 4‐chlorophenoxyacetic acid, and dicamba. The relative standard deviations of intra‐ and interday precision were 1.8–3.8 and 4.3–6.9%, and the recoveries after spiking were between 77.1 and 109.3%. The results showed that the material is a desired substituent for the extraction of compounds with benzene ring structure containing carboxyl groups.     

Effect of ammonium formate as ionizing additive in thermospray liquid chromatography-mass spectrometry for the determination of triazine,phenylurea and chlorinated phenoxyacetic acid herbicides

A comparison between the use of ammonium acetate and ammonium formate in thermospray liquid chromatography-mass spectrometry with positive and negative ion modes using ‘filament-on’ mode has been applied for the determination of simazine, atrazine, propazine, monuron, diuron, linuron, 2,4,-D, 2,4,5-T and silvex. By using ammonium formate, the positive ion mode showed for triazine and phenylurea herbicides [M + H]⁺ and [M + NH₄]⁺, respectively, and the formation of other adduct ions different from ammonium acetate. In the negative ion mode, chlorinated phenoxyacetic acid herbicides exhibited [M + acetate]^? or [M + formate]^?, depending on the ionizing additive. Applications are reported for the determination of triazine and chlorinated phenoxyacetic acid herbicides in spiked soil and water samples, respectively.     

Detection and determination of chlorophenols and chlorophenoxyacetic acids by instrumental analysis

A quantitative method for the determination of chlorophenols and chlorophenoxyacetic acids in aqueous solutions is described. The samples investigated contained 2-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol, 2,4,6-trichlorophenol and their phenoxyacetic acid derivatives. The total amount of chlorophenols is determined by spectrophotometry, the ratio of individual chlorophenols by gas chromatography and the total quantity of phenoxyacetic acids by acidimetric titration. The determinations are carried out after extraction with diethyl ether, carbon tetrachloride and petroleum ether, respectively.     

Photo-and thermochromic spiranes 26. Comparative study of the structure of benzoxazinone series spiropyrans using X-ray analysis

X-Ray analysis has been used to study the structure of a spiropyran in the series 4-oxodihydro-2H-1,3-benzoxazine with the molecular formula C₂₇H₂₃N₃O₅. The structural parameters for this spiropyran, which contains a phenoxyacetic acid hydrazide substituent, have been compared with those of other spiropyrans in this series. Dedicated to Edmund Lukevics on his 70^th birthday __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 103–108, January, 2007.     

Multi-analyte quantification in bioprocesses by Fourier-transform-infrared spectroscopy by partial least squares regression and multivariate curve resolution

This paper presents the quantification of Penicillin V and phenoxyacetic acid, a precursor, inline during Pencillium chrysogenum fermentations by FTIR spectroscopy and partial least squares (PLS) regression and multivariate curve resolution – alternating least squares (MCR-ALS). First, the applicability of an attenuated total reflection FTIR fiber optic probe was assessed offline by measuring standards of the analytes of interest and investigating matrix effects of the fermentation broth. Then measurements were performed inline during four fed-batch fermentations with online HPLC for the determination of Penicillin V and phenoxyacetic acid as reference analysis. PLS and MCR-ALS models were built using these data and validated by comparison of single analyte spectra with the selectivity ratio of the PLS models and the extracted spectral traces of the MCR-ALS models, respectively. The achieved root mean square errors of cross-validation for the PLS regressions were 0.22 g L⁻¹ for Penicillin V and 0.32 g L⁻¹ for phenoxyacetic acid and the root mean square errors of prediction for MCR-ALS were 0.23 g L⁻¹ for Penicillin V and 0.15 g L⁻¹ for phenoxyacetic acid. A general work-flow for building and assessing chemometric regression models for the quantification of multiple analytes in bioprocesses by FTIR spectroscopy is given.     

1-取代苯氧乙酰基-4-芳酰基氨基硫脲的合成及生物活性

苯氧乙酰肼;1-取代苯氧乙酰基-4-芳酰基氨基硫脲的合成及生物活性     

WO3纳米颗粒修饰ZnO纳米管的光催化性能

二甲四氯钠(MCPA-Na)是一种广泛用于牧场和果园的除草剂,但由于其生物降解性极低,已成为地下水和浅水中的主要污染物.研究发现,半导体可以有效地辅助降解转化危险化学品.ZnO纳米管因其中空结构和较大的比表面积,而在光催化降解有机物方面备受关注.但是,ZnO只能吸收紫外光,如果将其与窄带隙半导体进行复合,可以有效降低带隙,增强其在可见光区域的光吸收,表现出更好的光催化性能.WO3是一种具有稳定物理化学性质及耐光腐蚀窄带隙半导体.采用WO3修饰ZnO纳米管,能扩展ZnO吸收光的范围以及提高ZnO纳米管的耐光腐蚀性能.本文首先通过电化学合成的方法制备了ZnO纳米管,然后按照不同的W/Zn摩尔比将(NH4)6H2W12O40·XH2O滴加在纳米管表面,并在450 ℃下退火2 h制得ZnO-WO3纳米管阵列.研究了不同WO3含量的ZnO-WO3纳米管光催化降解MCPA-Na性能,并且通过X射线光电子能谱(XPS)、傅里叶红外光谱仪(FTIR)、紫外可见光谱(UV-Vis)和光致发光光谱(PL)等手段研究了复合WO3纳米颗粒后ZnO纳米管半导体光催化性能提高的原因.XPS结果表明,W元素在ZnO-WO3纳米管阵列中以W6+的形式存在.FTIR结果表明,复合WO3后的ZnO-WO3复合半导体上比纯ZnO纳米管表面具有更多的OH-基团.由于OH-可以捕获光生空穴,并转化为具有反应活性的●OH自由基,因此复合WO3能在一定程度上提高ZnO纳米管的光催化活性.UV-Vis结果表明,WO3的复合使得光谱发生明显红移,但随着WO3含量的增加,ZnO-WO3的吸光度明显增加.另外,PL结果表明,适当的复合WO3可以抑制光生电子-空穴的复合.这是因为W6+和晶格氧的相互作用产生了较高不饱和键和表面缺陷,而表面缺陷可以作为光生载流子的陷阱,促进了光生电子和空穴的分离,因而光催化性能提高.在模拟太阳光下研究了不同WO3含量的ZnO纳米管对光催化降解MCPA-Na溶液的性能.发现W/Zn摩尔比为3%的ZnO-WO3样品表现出最好的光催化活性,200 min内其降解率为98.5%.与纯ZnO纳米管相比,其光催化循环性能也有所提高.利用Mott-Schottky测试方法并结合UV-vis结果,我们计算得到不同WO3含量的ZnO-WO3复合半导体导带价带位置.由于WO3导带位置和价带位置都比ZnO的更高,WO3上产生的光生电子会向ZnO的导带移动,而ZnO光生空穴向WO3的价带移动,从而促使光生电子和空穴的分离,提高了光催化性能.但是如果WO3复合的量太大,则在ZnO纳米管上分散性不好,反而成为光生空穴和电子复合中心,导致其光催化活性降低.     

2-氨基苯并噻唑和苯氧乙酸衍生物的铜配合物：位模式和抗菌性能

以苯氧乙酸(Hpa)、对硝基苯氧乙酸(Hpnpa)和对甲基苯氧乙酸(Hpmpa)为原料,分别与2-氨基苯并噻唑(aben)和乙酸铜反应,合成了3种铜配合物[Cu(pa)2(aben)2](1),[Cu2(pnpa)4(aben)2](2)和[Cu(pmpa)2(aben)2].[Cu2(pmpa)4(aben)2](3),并通过元素分析、红外光谱和单晶X-射线衍射对其结构进行了表征。结果表明,3种配合物具有不同的配位模式,配合物1的中心Cu(Ⅱ)分别与2个羧基氧原子和2个噻唑环上的氮原子配位;配合物2的2个Cu(Ⅱ)则分别都与来自4个不同配体的羧基氧原子和1个噻唑环上的氮原子配位,从而在分子中形成了2个近乎垂直的八元环;配合物3为混配型化合物,1个Cu(Ⅱ)的配位数为4,另外2个Cu(Ⅱ)的配位数为5,参与配位的配体原子分别与配合物1和2相同。最低抑菌浓度的测定结果表明,3种配合物对真菌都表现出良好的抑制作用,且由于苯氧乙酸配体中取代基种类的不同,而使得配合物的抗菌效果出现明显的不同。     

Synthesis of Analogs of Juvenile Hormons Proceeding from Phenol Derivatives

New potential juvenoids, esters of alkenoic and alkadienoic acids with phenoxy- and phenoxyphenoxyethanol were synthesized, and also esters of phenoxyacetic acid with alkenols amd alkadienols.