1908—1932年羧酸的中文命名

论述了1908—1932年提出的各种中文有机化学命名方案对羧酸的命名,并以羧酸的两种西文命名法日内瓦命名法与羧基命名法为参照,分析了各方案命名羧酸的特点,尤其关注"酸"字在羧酸中文名称中的含义

Компьютерный расчет кривых кислотно-основного титрования

методические рекомендации и индивидуальные задания по дисциплине Аналитическая химия и физико-химические методы анализа для студентов химико-технологических специальносте

Applicability of head space solid phase microextraction (HS-SPME) with polyethylene glycol (PEG) fibre for GC-MS determination of volatile fatty acids in aqueous samples

A method consisting of head-space solid phase micro extraction (HS-SPME) followed by gas chromatography coupled with mass spectrometry (GC-MS) was developed for determination of volatile fatty acids in wastewater. A new fibre polyethylene glycol (PEG) was evaluated for the sample preparation. This fibre is designed to show high sample capacity, faster mass transfer during extraction, shorter equilibrium times and faster desorption process. The developed method showed good sensitivity with comparable limit of detection (LOD) and limit of quantitation (LOQ) values. The selection of various parameters included extraction time, extraction temperature, sample volume and desorption conditions. The experimental results showed low detection limits ranging between 0.01 mg/L to 0.06 mg/L for different acids. The new fibre was found to be efficient towards acetic and propionic acid

Tetrabutylammonium tribromide mediated condensation of carboxylic acids with alcohol

The direct condensation of various carboxylic acids and alcohols was achieved efficiently at reflux temperature under a solvent free condition using a catalytic amount of Tetrabutylammonium Tribromide (TBATB). Chemoselective acylation of primary alcohols in presence of secondary alcohols and phenols has been achieved. Steric factors in carboxylic acids played a crucial role during chemoselective acylation of diols. Reaction under a solvent free condition, absence of any dehydrating agent or use of any special techniques for removal of water and higher yields are the important features of this protocol

The possibilities of the assessment of volatile fatty acids

Tato bakalářská práce se zabývá obecnou charakteristikou mastných kyselin, popisem struktury a názvosloví těkavých mastných kyselin, vlastnostmi a oblastmi jejich výskytu. Dále jsou zmapovány možnosti identifikace těkavých mastných kyselin, mezi které se řadí plynová chromatografie, plynová chromatografie-hmotnostní spektrometrie, vysokoúčinná kapalinová chromatografie, mikroextrakce pevnou fází, spektrofotometrie a izotachoforéza. Plynová chromatografie je nejvyužívanější metodou detekce těkavých mastných kyselin. Při stanovení se tyto látky vzhledem k jejich chemickým vlastnostem většinou převádějí na methylestery.This bachelor's thesis deals with common characteristics of fatty acids by description of the structure and terminology of volatile fatty acids, by description of the characteristics and areas of their occurrence. Then possibilities of identification of volatile fatty acids are charted, to which gas chromatography, gas chromatography-mass spectrometry, high performance liquid chromatography, solid phase microextraction, spectrophotometry and isotachophoresis belong. Gas chromatography is the most frequently used method of the detection of volatile fatty acids. During the assessment these substances are mostly converted to methylesters because of their chemical characteristics.

Аналитическая химия. Справочные материалы

Содержатся справочные и фактографические данные, необходимые для выполнения всех видов расчетов по химическим методам анализа. Представлены справочные таблицы, формульные данные и примеры решения расчетных заданий, которые распределены по разделам в соответствии с программой курса и предварены методическими указаниями по применению справочных данных конкретного вида для решения химико-аналитических задач

Determination of volatile fatty acids in municipal wastewater by gas chromatography-mass spectrometry preceded by headspace- solid phase microextraction with PDMS-CAR fibre

An analytical procedure based on headspace – solid phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) has been developed for the determination of free volatile fatty acids in municipal wastewater samples. Polydimethylsiloxane-Carboxen (PDMS-CAR) fibre was found to have greater affinity to extract lower chain fatty acids. Extraction and gas chromatographic parameters of importance such as desorption time, sample volume, amount of salt to be added and extraction time have been optimized. Detection limits were in the low to medium mg/L levels. To evaluate the applicability of the developed HS-SPME procedure on real samples, municipal wastewater treatment plant samples were analysed

Харьковская областная химическая олимпиада 2011 года. Задачи и решения.

Пособие содержит задачи ІІІ этапа 48-ой Всеукраинской химической олимпиады в Харьковской области и их решения. Предназначено для преподавателей ВУЗов, учителей химии, а также для всех, кто интересуется химией

Zwitterionic Rhodium and Iridium Complexes Based on a Carboxylate Bridge-Functionalized Bis-N-heterocyclic Carbene Ligand: Synthesis, Structure, Dynamic Behavior, and Reactivity

A series of water-soluble zwitterionic complexes featuring a carboxylate bridge-functionalized bis-N-heterocyclic carbene ligand of formula [Cp MIIICl{(MeIm)2CHCOO}] and [MI(diene){(MeIm)2CHCOO}] (Cp* = 1, 2, 3, 4, 5-pentamethylcyclopentadienyl; M = Rh, Ir; MeIm = 3-methylimidazol-2-yliden-1-yl; diene = 1, 5-cyclooctadiene (cod), norbornadiene (nbd)) were prepared from the salt [(MeImH)2CHCOO]Br and suitable metal precursor. The solid-state structure of both types of complexes shows a boat-shaped six-membered metallacycle derived of the ¿2C, C' coordination mode of the bis-NHC ligand. The uncoordinated carboxylate fragment is found at the bowsprit position in the Cp MIII complexes, whereas in the MI(diene) complexes it is at the flagpole position of the metallacycle. The complexes [RhI(diene){(MeIm)2CHCOO}] (diene = cod, nbd) exist as two conformational isomers in dichloromethane, bowsprit and flagpole, that interconvert through the boat-to-boat inversion of the metallacycle. An inversion barrier of ~17 kcal·mol-1 was determined by two-dimensional exchange spectroscopy NMR measurements for [RhI(cod){(MeIm)2CHCOO}]. Reaction of zwitterionic Cp MIII complexes with methyl triflate or tetrafluoroboric acid affords the cationic complexes [Cp MIIICl{(MeIm)2CHCOOMe}]+ or [Cp MIIICl{(MeIm)2CHCOOH}]+ (M = Rh, Ir) featuring carboxy and methoxycarbonyl functionalized methylene-bridged bis-NHC ligands, respectively. Similarly, complexes [MI(diene){(MeIm)2CHCOOMe}]+ (M = Rh, Ir) were prepared by alkylation of the corresponding zwitterionic MI(diene) complexes with methyl triflate. In contrast, reaction of [IrI(cod){(MeIm)2CHCOO}] with HBF4·Et2O (Et = ethyl), CH3OTf, CH3I, or I2 gives cationic iridium(III) octahedral complexes [IrIIIX(cod){(MeIm)2CHCOO}]+ (X = H, Me, or I) featuring a tripodal coordination mode of the carboxylate bridge-functionalized bis-NHC ligand. The switch from ¿2C, C' to ¿3C, C', O coordination of the bis-NHC ligand accompanying the oxidative addition prevents the coordination of the anions eventually formed in the process that remain as counterions