流动注射在线分离分光光度法测定痕量总酚

在盐酸介质中，利用对氨基苯磺酸-亚硝酸钠-苯酚的重氮化-偶合反应，联用流动注射溶液处理技术，对工业废水在线自动化分离和预浓集处理，实现了实际样品中酚的在线分离富集及测定。利用单纯形优化法选择了最佳实验条件。方法的线性范围为0．1—20mg/L；进样频率为36／h；检出限为O．02mg／L。该方法用于工业废水中痕量酚的测定，其测定结果与4-氨基安替比林比色法对照，经统计学处理，没有显著性差异。     

Flow injection method for the fluorimetric determination of Zn with 8-(benzenesulphonamido) quinoline

The development of a fluorimetric method for the determination of zinc, based on the fluorescence of the zinc-8-(benzenesulphonamido) quinoline chelate in a micellar medium of sodium dodecylsulfate, is reported. The detection limit is 0.2 g l^–1, the working range is 0.5–700 g l^–1, and the sample throughput is 145 h^–1. The method was evaluated for the determination of zinc in food samples.A batch procedure for the simultaneous determination of zinc and cadmium, based on the synchronous and derivative spectra, is also proposed.     

A Proposed Process Control Chart for DC Plasma Spraying Process

A process control chart is proposed for DC plasma spraying process based on the in-flight simulation of the injected states of the particles determined by computational fluid dynamics analysis (via FLUENT V4.3). The chart consists of five regions, i.e., the unmelted, melted, vaporized, escaped, and rebounded, which represent the various states of the particles at impact on the substrate. The X and Y axes of the chart are particle entry conditions, i.e., diameter (ranging from 20 to 100 m) and injection velocity (between 10 to 50 m/s), respectively. The regions indicate the fate of the particle on impact. A grid-array of (14×11) entry conditions is simulated in developing the chart. The proposed chart is aimed at providing a general guideline for plasma spraying process in achieving a thoroughly melted particle on arrival at the substrate to be coated.     

Diphenylamino end-capped oligofluorenes with enhanced functional properties for blue light emission: synthesis and structure-property relationships

A novel series of monodisperse asymmetrically and symmetrically substituted diphenylamino end-capped oligofluorenes, OF(2)-NPhR, R = H or An (An = 9-anthryl) and OF(n)-NPh, n = 2-4, has been synthesized by a convergent approach using palladium-catalyzed Suzuki cross-coupling. End-capping of oligofluorenes with diphenylamino group(s) has been shown to offer advantages in terms of lowering their first ionization potentials, enhancing thermal stability, and inducing good amorphous morphological stability. By tuning the number of diphenylamino end-caps and the chain length, the optimal conjugated length for optical and luminescence properties has been determined. Of all the hitherto reported oligofluorenes capable of serving as non-doped blue emitters, OF(3)-NPh, with an optimal conjugated length, exhibits some of the best hole-transport and blue-emitting properties. A maximum luminance of 7500 cd m(-2) and a luminance efficiency up to 1.8 cd A(-1) have been achieved.     

A compact flow injection analysis system for surface mapping of phosphate in marine waters

The design, construction and validation of a compact, portable flow injection analysis (FIA) instrument for underway analysis of phosphate in marine waters is described. This portable system employs gas pressure for reagent propulsion and computer controlled miniature solenoid valves for precise injection of multiple reagents into a flowing stream of filtered sample. A multi-reflection flow cell with a solid state LED photometer is used to detect filterable reactive phosphate (0.2 mum) as phosphomolybdenum blue. All the components are computer controlled using software developed using the Labviewtrade mark graphical programming language. The system has the capacity for sample throughput of up to 380 phosphate analyses per hour, but in the mode described here was operated at 225 analyses per hour. Under these conditions, the system exhibited a detection limit of 0.15 muM, reproducibility of 1.95 % RSD (n=9) and a linear response (r(2)=0.9992) when calibrated in the field with standards in the range 0.81-3.23 muM. The system was evaluated for the mapping of phosphate concentrations in Port Phillip Bay, south eastern Australia, and during the course of a 150 km cruise, 542 analyses were performed automatically. In general, good agreement was observed between analyses obtained using the portable FIA system and those obtained from manual sampling and laboratory analysis.     

Enzyme-linked flow-injection immunoassay using immobilized secondary antibodies

A fast, non-equilibrium enzyme-linked flow-injection immunoassay (FIIA) system using an immobilized secondary-antibody reactor is described. The assay method is based on the competition between the enzyme-labeled antigen and analyte (unlabeled antigen) for a limited amount of soluble primary-antibody binding sites. This mixture is then introduced via flow-injection into the secondaryantibody reactor. The reactor bound enzyme activity, as measured by flowing an appropriate substrate solution through the reactor, is inversely proportional to the concentration of free analyte in the sample. By using non-equilibrium conditions, a single assay takes a total time of 13 min or less including regeneration of the reactor. To illustrate the application of this system, theophylline and insulin were chosen as model hapten and macromolecule analytes, respectively. Preliminary studies suggest that the new FIIA system is suitable for determining theophylline in serum with acceptable accuracy and precision.     

New design of a radio-frequency plasma torch

A numerical model has been developed for predicting the two-dimensional flow and temperature fields in a radio-frequency (rf) plasma torch. The method employed here is based on Boulos' model with the exception of the boundary conditions for the electric and magnetic field equations. Calculations have been made for the confirmation of a new sample injection method, which is capable of completely evaporating refractory materials at high feeding rates without interfering with the stability of the plasma. In the newly designed torch, the reagent is radially injected into the hottest part of the plasma through quartz capillary tubes set symmetrically between an inductor coil. Experimental investigations have also been performed for verifying the proper function of the design. These results provide evidence that our radial injection method developed here is more effective in practical processing than the conventional axial injection methods.     

用流动注射二甲基偶氮磺-Ⅲ分光光度法测定水中硫酸根

基于硫酸根使Ｂａ２＋－二甲基偶氮磺－Ⅲ络合物的褪色反应，将采样环和离子交换柱安 装在多功能进样阀上消除干扰，建立了流动注射光度测定硫酸根的新方法。该法对硫酸根线 性范围为０～２６ｍｇ／Ｌ。所建立方法在进样时对离子交换柱自动再生处理，有望应用于硫酸根 的自动测定。     

Field-amplified sample injection and in-capillary derivatization for sensitivity improvement of the electrophoretic determination of histamine

The feasibility of the combination of field-amplified sample injection (FASI) and in-capillary derivatization was explored for improving sensitivity of histamine in capillary electrophoresis (CE). Naphthalene-2,3-dicarboxaldehyde (NDA) was used as derivatization reagent. The reagent and sample was introduced by tandem mode. The derivatization was accomplished by at-inlet mode with standing time of 1.5 min. The combination of FASI and in-capillary derivatization was successfully achieved with about 400-fold concentration sensitivity enhancement compared to pre-capillary derivatization at the same set-up. The detection limit of concentration for histamine reached 1.25 x 10(-11) M by CE and fluorescence detection with S/N = 3. Parameters affecting FASI and in-capillary derivatization process including sample matrix, buffer concentration and reagent injection amount, were investigated.     

FIA Determination of Paracetamol in Pharmaceutical Drugs by Using Gold Electrodes Modified with a 3‐Mercaptopropionic Acid Monolayer

A flow injection analysis (FIA) method for the determination of paracetamol in pharmaceutical drugs using a gold electrode modified with a self‐assembled monolayer (SAM) of 3‐mercaptopropionic acid is described. At optimized experimental conditions the dynamic concentration range was 0.15 to 15.0 mg L^?1 with a detection limit of 0.2 μg mL^?1 (S/N=3). The repeatability of current responses for injections of 10 μmol L^?1 paracetamol was evaluated to be 3.2% (n=30) and the analytical frequency was 180 h^?1. The lifetime of the modified electrode was found to be 15 days. The results obtained by using the proposed amperometric method for paracetamol determination in four different drug samples compared well with those found by spectrophotometry.