Bifok Ab

Zellweger Uster Ag

Block Engineering, LLC

Elo H Hansen

Jaromir Ruzicka

Hans Jorgen Ibsen Nielsen

One or more components are determined in a sample by bringing said sample, which can be a liquid or a gas, into contact with a medium for adsorbing or taking up the components in question. A light beam is led via an optical cable through the medium containing the adsorbed or taken-up compound sought for, is reflected against a reflector material back through the medium, and the emitted light beam is detected. In enzymatic reactions, inter alia, a membrane can be utilized between sample solution and reagent, said membrane enabling the actual component to diffund through the membrane and react with enzyme, avoiding thereby the measurements to be disturbed by strong coloration and/or a high content of impurities in the sample solution. The membrane thereby serves as a reflector material for the light beam.

Method for non-segmented continuous flow analysis based on the

Sample injection system for nonsegmented, continuous flow analysis comprising an inlet channel, an analyzer channel and a carrier stream channel connected in a confluence point, an aspirating pump in the analyzer channel, a carrier stream pump in the carrier stream channel with a higher capacity than the aspirating pump and an analyzer. In a first step prior to the sample injection, the carrier stream pump forwards carrier stream to the confluence point, the aspirating pump sucks carrier stream from the confluence point, at a lower rate than the carrier stream pump and an outflow of carrier stream drains through the inlet channel. In a second step, the carrier pump is stopped, the inlet end of the inlet channel is brought in contact with the sample solution, and the aspirating pump sucks sample into the inlet channel and the analyzer channel. In the third step, the carrier pump is restarted, whereby the sample in the analyzer channel is aspirated into the analyzer, and all the sample in the inlet channel is pressed out into the waste. The analyzer may be a flow through detector, dialyzer, or any other apparatus for analysis. The performance can also be made as a multichannel system for simultaneous analysis of several components in different analyzers.

Sample introduction system for nonsegmented continuous flow analysis

A sample introduction system comprises a sampling circuit and a carrier stream circuit where the two circuits share a volumetric conduit which is at all times connected to and simultaneously opened to both sampling and carrier circuits. This system allows, by a controlled combination of hydrostatic and hydrodynamic forces, to create a well-defined sample zone within the volumetric circuit and then to transport this zone, in a well-reproduced manner, into a continuous flow analyzer where an assay of sample solution components may be performed quantitatively, if necessary even with the aid of chemical reactions, from the signal as provided by a flow-through detector.

Hydrodynamic sample introducing system

A continuous method of quantitatively determining slowly reacting compounds with the use of a single measuring cell, the sample being injected into a continuously flowing carrier solution which is already provided with, or simultaneously with the sample is provided with reagent to form a sample zone in the form of a reproducable gradient. Said sample zone is led into a measuring cell whereupon the flow is stopped by means of shunting the carrier flow, by stopping the pump, or by means of a valve. The reaction is allowed to take place in the measuring cell while a magnitude, characteristic for the reaction, is registered. The reaction speed can be detected from the incline of the obtained response curve and the amount of the sought-after compound is calculated. By means of setting the stop at a certain point in the concentration gradient curve and always selecting said point at the same time distance from the peak of the gradient curve during flow, a total reproducability of the analysis is ensured.

Stop-flow analysis

A continuous method of quantitatively determining slowly reacting compounds with the use of a single measuring cell, the sample being injected into a continuously flowing carrier solution which is already provided with, or simultaneously with the sample is provided with reagent to form a sample zone in the form of a reproduceable gradient. Said sample zone is led into a measuring cell whereupon the flow is stopped by means of shunting the carrier flow, by stopping the pump, or by means of a valve. The reaction is allowed to take place in the measuring cell while a magnitude, characteristic for the reaction, is registered. The reaction speed can be detected from the incline of the obtained response curve and the amount of the sought-after compounds is calculated. By means of setting the stop at a certain point in the concentration gradient curve and always selecting said point at the same time distance from the peak of the gradient curve during flow, a total reproduceability of the analysis is ensured.

Continuous flow analysis with an unobstructed, unsegmented carrier stream transporting a sample plug through a main conduit from a sample injection station to a flow-through detector. One or more reagents are injected in the sample plug on its way through the main conduit, the dispersion being controlled to optimize the conditions of chemical reaction. The reagents are added by being pumped in intermittently in merging streams, at least one of the solution delivering devices being activated and deactivated at pre-programmed time intervals during each sampling cycle. Each cycle is initiated by injecting the sample solution at the sample injection station. The solution delivering devices can have various pumping rates and at least one pump may be an automatic burette. The delivery is controlled by a timer or microcomputer, and the transport of solution can be momentarily stopped before the sample plug enters or while it is inside the flow-through detector.

Flow injection analysis with intermittent flow

Method and device for continuous flow-through analysis with a non-segmented laminar carrier flow, to which reagents are added at programmable intervals. The programming can be done by switching in various loops with valves, interchangeable connections or by composing the apparatus of different prefabricated modules to produce the desired reaction conditions.

Programmable, continuous flow analyzer

A method and an apparatus for instantaneously determining ions in a carrier solution by means of leading it into a very thin continuous layer over the sensitive surface of an ion-selective electrode in a measuring cell and, from said measuring cell, on to a reservoir having a reference electrode so that the potential difference between the electrodes in the measuring cell can be continuously registered. The apparatus consists of a circuit having an inlet conduit, a pump, a sample addition apparatus, a loop, the measuring cell and a conduit via the pump to an outlet. The liquid level in the measuring cell is held constant, the ion-selective electrode being arranged above the liquid level and the reference electrode being immersed in the solution.

Automatic analysis of alkali metals halides etc. by means of the use of

The present invention relates to an electrode for measuring the nitrate concentration in aqueous solutions. The electrode consists of a container with an internal reference system and a membrane which is a combination of an organic nitrate sensor phase of a quaternary ammonium salt as electroactive material, an organophilic, hydrophobic solvent for the quaternary ammonium salt with substantial viscosity and polyvinyl chloride or polyurethane as non-porous material. The quaternary ammonium salt is chosen from the group consisting of: tetraoctyl ammonium nitrate, tetranonyl ammonium nitrate, tetradecyl ammonium nitrate, tetraundecyl ammonium nitrate, tetradodecyl ammonium nitrate, tetratridecyl ammonium nitrate and tetratetradecyl ammonium nitrate; and the solvent consists of dialkylphthalate or a dialkyladipate of a solubility parameter of 9 .+-. 2 (cal/cm.sup.3).sup.1/2.

Nitrate ion selective electrode

A continuous flow analytical system in which there is provided a continuous unobstructed carrier stream into which discrete volumes of sample solutions to be observed for reaction with the carrier stream are injected successively. A detector for measuring the results of any reaction between the carrier stream and sample solutions is positioned downstream from the point of injection.

Automatic chemical analyzer

An electrochemical cell for measuring the gas content in a solution, said electrochemical cell having a potentiometric ion sensitive electrode and a reference electrode, said electrodes being in electrochemical contact through an electrolyte solution, said electrolyte solution forming a thin, continuous, stabilized, stationary layer covering the surface of said ion sensitive electrode so that said thin electrolyte layer is in direct physical contact with a gaseous phase.

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Lyngby, Denmark

Elo H Hansen