Chemical analysis of materials.

The essential oils from the needles and branch of the Abies delaveyi subsp. fansipanensis was collected in Hoang Lien Natural Park, Lao Cai province and was obtained by steam distilation and the yields of essential oils were 0.27% and 0.08% from air-dry material. By the using GC/MS analysis, there are 44 and 52 constituents from needles and branch were identified and accounting 97.75% and 96.86% essential oil.

6p meyerowitz 25-12-2021 24 2   Download

It was demonstrated that Poly(p-Xylylene) (PPX) could be prepared from α,α’-Bis(Alkoxy or Aryloxy) –p-Xylenes via chemical vapor decomposition (CVD)- method. This is one-step process and there are side products by the CVD-process. This effect depends both on the CVD- condition and the properties of the starting monomer. The structure and thermal behavior of the material were characterized by FTIR, UVvis spectroscopy, elemental analysis, wide-angle X-ray diffraction, DTA and DSC.

14p 12120609 01-06-2020 13 1   Download

The oxide reduction diffusion (ORD) procedure has recently been applied in synthesizing hydrogen storage materials AB5 for Ni-MH batteries. Starting from metal hydroxides and La oxalat precursor, superfine powder alloys LaNi5, LaNi4.5Co0.5 and LaNi3.87Mn1.13 were obtained by this “soft-chemistry” route. Chemical composition, structure and morphology of alloy phases were examined by different analysis techniques such as AAS, EPMA, X-ray and TEM. The H2-absorption and desorption behavior of crystalline products was determined by Sieverts’ method.

9p uocvong01 24-09-2015 35 2   Download

Complexometric titrations many metals form complex with a ligand: Cu++ + NH3 ⇔ Cu(NH3)++ Cu(NH3)2+ + NH3 ⇔ Cu (NH3)22+ Cu (NH3)22+ + NH3 ⇔ Cu (NH3)32+ Cu (NH3)32+ + NH3 ⇔ Cu (NH3)42+ Kf1 Kf2 Kf3 Kf4 Zn (NH3) complexes vs lg NH3 α .• theoretically could titrate Zn with ammonia • stepwise Kf very similar • difficult to know stoichiometry • to ensure all one form, need excess NH3 • titration never gives good equivalence point • can’t use monodentate ligand to titrate metals Titrations with EDTA • • • • use multidentate ligands e.g.

13p doilan 26-01-2013 42 3   Download

-Systematic and random error -Accuracy vs precision -Significant figures -Average and standard deviations ENVI 15 - Analytical Chemistry Lecture 2 Quality Assurance Quality Assurance/Quality Control (QA/QC) Review Harris Chapter 5 A program to produce high quality data with known uncertainty. ENVI 15 - Analytical Chemistry Lecture 2 .

11p doilan 26-01-2013 70 5   Download

Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials.[1] Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of one or more of these components. The separation of components is often performed prior to analysis

10p doilan 26-01-2013 78 4   Download

Is a branch of polymer science dealing with analysis and characterisation of polymers. üThe complication of macromolecular chains, the dispersion in molecular weight, tacticity, crystallinity, orientation, composition of polymers etc. and complex morphological systems ⇒ analysis of polymer ≠ the small organic materials ⇒ Focus on viscoelastic properties, dynamic mechanical testing.

114p buitiendung87 06-01-2011 338 154   Download

Introduction: An organophosphorus nerve agent VX (O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, Figure 2.1) shows potent inhibitory action on acetylcholinesterase; its development, production, stockpiling and use are being prohibited by the CWC international treaty as a chemical weapon together with those of sarin and soman. In addition, even material compounds for VX synthesis are being also controlled strictly. In the world history, there had been no records on the use of VX in any international dispute.

9p bigbaby87 01-09-2010 99 10   Download

Introduction: Toluene, benzene, xylene and styrene are being widely used for chemical product materials, solvents and constituents of adhesives and paints, and thus sometimes cause poisoning incidents by inhaling their gas at chemical product-manufacturing factories. The abuse of thinner solvents, containing toluene, benzene and xylene, is now a social problem especially for young people. There are many crimes and poisoning incidents involving the thinner solvent abuse.

4p bigbaby87 01-09-2010 164 25   Download

Introduction: Chloroform exerts a suppressing effect on the central nervous system. It had been used as a general anaesthetic since the 19th century, but it disappeared, because of its hepatotoxicity and arrhythmia-inducing effects. It is now being used for industrial purposes, such as a solvent, extracting reagent, refrigerant and chemical material. Chloroform poisoning can be seen in accidental, suicidal [1] and homicidal cases.

5p bigbaby87 01-09-2010 114 16   Download