Jaromír Růžička

The second coming of flow-injection analysis

Abstract The state of art of the flow-injection technique is reviewed and its future development is outlined by emphasizing the importance of stopped-flow and sequential injection methodologies and by discussing common aspects of flow injection and chromatographic techniques.

From flow injection to sequential injection: comparison of methodologies and selection of liquid drives

Recommendations are made on how to select and to configure components of a sequential injection system. Evaluation of sequential injection system performance is highlighted by comparing peristaltic and piston pumps by monitoring the repeatability of the volumes and delivery rates under conditions of forward, stopped and reversed flow. Examples of the use of sequential injection with a peristaltic pump are outlined.

Novel single standard calibration and dilution method performed by the sequential injection technique

A novel single standard calibration and dilution method utilizing the sequential injection analysis (SIA) technique is described. The SIA manifold employes a dilution conduit for storing a concentration gradient of an injected analyte, which provides for a variable calibration and dilution scheme suitable for both single and multizone analyses by taking selected aliquots from the gradient. This paper describes the principles of the method, the experimental characterization of the SIA manifold with Bromothymol Blue dye using a spectrophotometric detector and the application of the method to glucose determination using glucose oxidase by sensor injection analysis and by multizone stopped-flow analysis.

A new principle of activation analysis separations—I: Theory of substoichiometric determinations

Abstract Separation procedures in the activation analysis of elements mainly consist of many steps which are usually derived from classical analysis schemes. In all cases an excess of reagent (precipitating, complexing, etc. ) is used for separation of the element to be determined. In the present paper separations by means of a smaller amount of reagent than corresponds to the stoichiometric ratio of element to be determined are discussed. The use of an insufficient amount of the reagent has two advantages : greater selectivity (possibility of eliminating many steps) and elimination of the necessity for determining the chemical yield of the element in question. As a result the analysis is more rapid.

Flow injection analysis and chromatography: twins or siblings? Plenary lecture

The purpose of this survey of liquid chromatography and flow injection analysis, which reveals their common background and shared features, the various novel approaches possible and the lack of a unified theory, is to highlight the compatibility of these techniques and to promote the interaction and exchange of ideas between areas of the newly emerging discipline of “injection techniques,” in the field of flow analysis.

Tutorial review. Discovering flow injection: journey from sample to a live cell and from solution to suspension

Twenty years after its inception, flow injection is seen as an ever-expanding method, as new modifications are discovered such as flow injection cytoanalysis and the flow injection on renewable surfaces technique. In this review, a personal view of the future rather than the history of flow injection is given, with comment on how research is actually being conducted.

Flow injection analysis — a survey of its potential for continuous monitoring of industrial processes

Abstract Flow-injection methods provide a number of approaches to monitoring. Those discussed include sample injection into a flowing reagent stream, continuous pumping of sample and merging with a reagent stream, and injection of reagent into a sample stream. Peak-height measurements are normally used in these systems, but peak-width measurements can have advantages. Means of achieving multidimensional flow-injection analysis are discussed briefly.

Metal chelate exchange in the organic phase-II Extraction and exchange constants of dithizonates and diethyldithiocarbamates.

Dithizonates and diethyldithiocarbamates of Ag, Tl(I), Cu(II), Zn, Cd, Hg(II), Pb, Fe(II), Co(II), Ni, Pd(II), In(III), As(III), Sb(III), Bi, Se(IV) and Te(IV) have been prepared and their reactions in carbon tetrachloride have been studied spectrophotometrically. From the exchange constants determined, the extraction constants of metal diethyldithiocarbamates have been calculated. Where formation of mixed chelates has been observed, corresponding exchange constants have been determined. Finally, the influence of organic solvents (CCl(4), CHCl(3), C(6)H(6) and C(6)H(5)Cl) on the exchange reaction of zinc diethyldithiocarbamate with dithizone has been investigated.

Trace metal atomic absorption spectrometric analysis utilizing sorbent extraction on polymeric-based supports and renewable reagents

Various methods of analyte preconcentration for atomic absorption spectrometry are available for trace metals in aqueous samples. Among the drawbacks of many of these techniques are the generation of hazardous or toxic wastes, poor preconcentration efficiencies and cumbersome on-line implementation of the particular technique. Preconcentration of trace metals by sorbent extraction utilizing a flow injection method is described. Preconcentration of the analyte is accomplished by its extraction on a solid-phase hydrophobic support prepared by adsorption of a suitable chelating agent. Following extraction of the analyte, the metal–chelate complex is eluted from the solid support by changing the polarity of the carrier stream. The metal systems chosen for examination were copper and lead chelates of diethyldithiocarbamate (DDC) and quinolin-8-ol. Some results are presented for other chelates, namely 4-(2-pyridylazo)resorcinol, 1-(2-pyridylazo)-2-naphthol and dithizone. The sample throughput of the method was 20 h–1 utilizing 2 ml of sample per analysis for preconcentration. The detection limits using the quinolin-8-ol and DDC chelates are at low parts-per-billion levels, with enhancement factors between 50 and 100.

Use of a flow-injection system in the evaluation of the characteristic behavior of neutral carriers in lithium ion-selective electrodes

Abstract A flow-injection system based on microconduits is used to investigate electrode characteristics such as selectivity, detection limit, and response and equilibrium times of the new ionophore, N,N,N′,N′-tetraisobutyl-5,5-dimethyl-3,7-dioxanonane diamide, in lithium ion-selective electrodes. These characteristics were compared with those of the ionophore N,N′-diheptyl-N,N′,5,5-tetramethyl-3,7-dioxanone diamide. The new ionophore has superior detection limits and shorter response and equilibrium time, but the other exhibits better selectivity for lithium with respect to sodium. Values of KPotLiNa for the new ionophore vary from 0.0450 to 0.566, depending on the methods of measurement and solution conditions. This phenomenon is discussed. Stop-flow experiments effectively demonstrated the response and equilibrium time differences between these two ionophore membranes.