Polymer Surfactants a; Analytical Reagents——Synthesis of PPOTA and PPOCA and Their Analytical Properties

Two new polymer surfactants poly(propylene oxide)-a-tetradecyl-dimethylammonium chloride(PPOTA) and poly(propylene oxide)-a-cetyl-dimethylammonium chloride(PPOCA) were synthesized,which possess the characteristics of both cationic and nonionic surf actants.The properties of PPOTA and PPOCA were investigated.The synthesized surfactants can be used as sensitizing and solubilizing reagents for spectrophotometric analysis.Some examples of micellae improved by spectrophotometric systems such as Sc(Ⅲ)-CAS,Ge(Ⅳ)-PF and Ni(Ⅱ)-CAS were given.     

Analytical Chemistry — today''s definition and interpretation

Conclusions Today Analytical Chemistry requires a broader definition than that concerned with its classical concept, objectives and methodology. The new concept of sample as a condensation of information of analytical interest has to be considered, as well as the increasing amount of instrumentation and metrology (physics) and data processing (applied mathematics; chemometrics) which are part of the present holistic definition of the subject. This is because the actual goals and constantly growing new objectives which today's Analytical Chemistry has to face and accomplish, are bound to a preliminary, strategic overview of the analytical problem (which often means much more than a simple sample). This problem has to be solved by the sensible, tactical application of the most suitable analytical method(s), worked out by Analytical Chemistry, the mother science of its instrument, chemical analysis.     

Analytical Chemistry — today''s definition and interpretation

Conclusion The definition of Analytical Chemistry given above reflects not only the place, importance, structure and functions of this science today but also the trends in its evolution. Its nearest perspective are the rise of analytical knowledge to the higher levels in the hierarchy of the system of chemistry, the creation of new analytical methods for study of the composition, structure and dynamics of ever more highly organized chemical objects up to living reactors.     

Analytical Chemistry — today''s definition and interpretation

Conclusion Although this multidisciplinary branch of science is growing rapidly today, yet two main points remain unchanged. On the one hand, it is analytical in essence; on the other, the information which it aims to acquire is chemical in nature, i.e. within the domain of chemistry. Accordingly it seems pertinent to reserve the term Analytical Chemistry for it. Other terms like analytical physics and chemical characterization are one-sided, with the aim or essence missing. The same is true of analytics and analytical science. Moreover, they should, literally speaking, include analytic geometry, analytical mechanics and so on.     

Analytical characteristics and sensitivity mechanisms of electrolyte-insulator-semiconductor system-based chemical sensors—a critical review

Recent trends in research and development of electrolyte-insulator-semiconductor (EIS) field-effect chemical sensors (ion-selective field-effect transistors, light-addressable potentiometric sensors, capacitive EIS-sensors) with inorganic gate insulators (oxide, nitride and chalcogenide films) are reviewed. Physical properties of EIS systems and basic mechanisms of their chemical sensitivity are examined. Analytical characteristics and sensing mechanisms of EIS pH sensors with oxide and nitride films, as well as metal ions sensors with chalcogenide films, are critically discussed. Prospects of future research on EIS field-effect biosensors are briefly outlined.     

The Interaction between Propranolol and Gold Nanoparticles and its Analytical Application

The addition of propranolol induced the aggregation of gold nanoparticles, and increased Rayleigh light scattering (RLS) intensity greatly. The interaction between them was studied by RLS spectrum, UV-Vis spectrum and transmission electron microscopy (TEM). Based on these results, a novel method was proposed for propranolol assay. With the combination of solid phase microextraction (SPME), the proposed method was successfully applied to determine propranolol in urine.     

MECA Spectroscopy—A New Flame Analytical Technique

Abstract

A review is presented of molecular emission cavity analysis (MECA) spectroscopy. The technique is described, and applications to the determination of trace concentrations of a wide range of non-metals are outlined.     

Analytical Chemistry — a time for change?

A report of the RSC-Analytical Division Automated Methods Group Symposium, held in Ferndown, Dorset, U.K., 28–30 October 1987.     

Analytical and statistical studies of Rodriguez–Velazquez indices

Journal of Mathematical Chemistry - In this work we perform analytical and statistical studies of the Rodríguez–Velázquez (RV) indices on graphs G. The topological RV(G) indices,...     

Investigation of Chemiluminescence with Electrogenerated Reagents and Its Analytical Application

In this paper, studies on chemiluminescence (CL) systems with electrogenerated reagents, including BrO^-, ClO^-, Br2, [Cu-(HIO6)2]^5-, H2O2, Mn^3 , Co^3 and Ag^2 , are described.The analytical applications of the CL system with electrogenerated reagents are reviewed.     

Ion Recognition and Analytical Application of a Fibroin Modified Electrode

A novel fibroin modified electrode with ion recognition was reported. The membrane with isoelectric point of pH 4.5, was modified on graphite and carbon fiber electrodes. The pH-responsive ion recognition of the modified electrode was investigated by use of some neurocompounds. The fibroin carbon fiber electrode has been used for in-vivo determination.     

Chemiluminescence of Luminol-potassium Ferricyanide with Benserazide and Application in Analytical Chemistry

Benserazide (D, L-serine-2-[2,3,4-(trihydroxyphenyl)methyl]hydrazide) is one of aroma- tic L-amino acid decarboxylase inhibitors, and used with levodopa for treatment of Parkinson’s disease1. Hence, determination of benserazide is an indispensable program. Recently, chromatography2, spectrophotometry3,4 and capillary electrophoresis5 have been used for the determination of benserazide. However, these methods are low sensitive and inconvenient. In order to search new method for detecting ben…     

Ant Colony Algorithm and Optimization of Test Conditions in Analytical Chemistry

The research for the new algorithm is in the forward position and an issue of general interest in chemometrics all along.A novel chemometrics method,Chemical Ant Colony Algorithm,has first been developed.In this paper,the basic principle,theevaluation function,and the parameter choice were discussed.This method has been successfully applied to the fitting of nonlinear multivariate function and the optimization of test conditions in chrome-azure-S-Al spctrophotometric system.The sum of residual square of the results is 0.0009,which has reached a good convergence result.     

Studies on the Preparation and Analytical Applications of Various Metal Ion-Selective Membrane Electrodes Based on Polymeric,Inorganic and Composite Materials—A Review

Ion-selective membrane electrodes commonly known as electrochemical sensors are important in view of the ability to make direct or indirect measurement of various metal ions. The fact is that the use of ion-selective electrodes for such type of measurements requires relatively inexpensive equipment, which makes ion-selective electrodes attractive to scientists in many disciplines. Thus, potentometric sensors can offer an inexpensive and convenient method for the analysis of heavy metal ions in solutions providing acceptable sensitivity and selectivity. For this purpose, many organic, inorganic, chelating, intercalating and composite materials were studied as electroactive materials for the preparation of ion-selective membrane electrodes. The present study provides a detailed review of literature for the fabrication, characterization and analytical applications of ion-selective membrane electrode based on different electro active components.     

Analytical methods for selected emerging contaminants in human matrices—a review

Emerging contaminants are a broad category of chemicals, previously unknown or unrecognized as being of concern, but which, because of their potential health effects associated with human exposure, are under increasing scrutiny. To accurately measure their levels in biological matrices, specific and sensitive analytical methods have recently been developed. We have reviewed here the methods used for analysis of selected emerging organic contaminants, for example metabolites of organophosphate triesters, metabolites of new phthalates or phthalate substitutes, perchlorate, organic UV filters, and polycyclic siloxanes, in human matrices. Although the use of new techniques and approaches has been emphasized, we also acknowledge methods previously used for other contaminants and adapted for the emerging contaminants listed above. In all cases, chromatography and mass spectrometry were the techniques of choice, because of their selectivity and sensitivity for measurements at ng?g^?1 levels. Critical issues and challenges have been discussed, together with recommendations for further improvement in particular cases (e.g. metabolites of phthalates or their substitutes). In particular, the use of labeled internal standards, the availability of certified reference materials, and the need for interlaboratory comparison exercises are key aspects of further development of this field of research.

NEWS——卢建忠、施国跃、肖丹在Analytical Chemistry上发表的研究成果简介

来自复旦大学的卢建忠课题组设计出了正己烷催化化学发光传感器。该研究发表在Anal.Chem.,2007,79(4),1425-1432。该传感器基于固体催化剂表面的化学发光,不需要光源,也没有发光试剂不断被消耗和脱落的缺点。相比于常见的催化剂,分子筛催化剂具有均匀的通道和空腔,能够有效筛分特定的反应物和产物,很好地识别结构相似的同系物。此外,其酸碱性可通过离子交换加以调节,为改善气体传感器的选择性和灵敏度提供新的思路。