Boehringer Mannheim Gmbh

The Trustees of Flinders University

Roche Diagnostics Gmbh

F. Hoffmann-La Roche Ag

Michael-Harold Town

Uwe Herrmann

Georg-Burkhard Kresse

Michael N Berry

Joachim Siedel

Joachim Ziegenhorn

Wilhelm Tischer

Lieselotte Schellong

Josef Heinle

Johnny Staepels

Uwe Hermann

A process and a reagent for the determination of ions in fluids, wherein the influence of these ions on the activity of an enzyme is measured. The ions for example are sodium, potassium, calcium, magnesium, manganese, lithium, lead, zinc, copper, iron or other heavy metals or non-metallic ions comprising chloride, bicarbonate, protons, ammonium and substances that give rise to ammonium. The enzymes which are used may be a transferase, a hydrolase, an oxidoreductase or a lyase. An essential feature is a method to exclude interferences by ions by masking the interfering ions with a binding agent.

Process for determination of ions in fluids by masking of interfering

Determination of potassium ions in fluids

Determination of ions in fluids

Determination of ions in fluids by a process involving displacement of

Determination of sodium ions in fluids

Enzymatic determination of analyte ions in fluids by optimizing

A process for the determination of substrate or enzyme activities by the use of a redox reaction as a measurement reaction is carried out in the presence of one or more additionally added tetrazolium salts to remove disturbing substances. The tetrazolium salts have the formula ##STR1## in which R.sup.1 is a hydrogen atom, a carboxyl group or an alkyl, phenyl, nitrophenyl, dinitrophenyl, carboxyl-substituted phenyl or trialkylammoniumphenyl radical, R.sup.2 is a phenyl, nitrophenyl, biphenylyl or naphthyl radical, R.sup.3 is a phenyl, carboxyl-substituted phenyl, carboxyl-substituted hydroxyphenyl or dimethylthiazolyl radical, and A.sup..crclbar. is a monovalent anion. The formazanes formed by reaction with reducing substances do not absorb light at all, or absorb light only to a negligible extent, at the measurement wavelength of the redox reaction. New compounds included within the structural formula are those in which R.sup.1 is carboxy, phenyl, 2-carboxyphenyl, 4-carboxyphenyl, 2,4-dinitrophenyl or 4-trimethylammoniumphenyl, R.sup.2 is phenyl, and R.sup.3 is phenyl or 2-carboxyphenyl; with the proviso that, when R.sup.3 is unsubstituted phenyl or 2-carboxyphenyl, R.sup.1 may not be unsubstituted phenyl.

Process and reagent for the determination of substrates or enzyme

A process for the determination of substrate or enzyme activities by the use of a redox reaction as a measurement reaction is carried out in the presence of one or more additionally added tetrazolium salts to remove disturbing substances. The tetrazolium salts have the formula ##STR1## in which R.sup.1 is a hydrogen atom, a carboxyl group or an alkyl, phenyl, nitrophenyl, dinitrophenyl, carboxyl-substituted phenyl or trialkylammoniumphenyl radical, R.sup.2 is a phenyl, nitrophenyl, biphenylyl or naphthyl radical, R.sup.3 is a phenyl, carboxyl-substituted phenyl, carboxyl-substituted hydroxyphenyl or dimethylthiazolyl radical, and A.sup..crclbar. is a monovalent anion. The formazanes formed by reaction with reducing substances do not absorb light at all, or absorb light only to a negligible extent, at the measurement wavelength of the redox reaction. New compounds included within the formula are those in which R.sup.1 is carboxy, phenyl, 2-carboxy, phenyl, 2-carboxyphenyl, 4-carboxyphenyl, 2,4-dinitrophenyl or 4-trimethylammoniumphenyl, R.sup.2 is phenyl, and R.sup.3 is phenyl or 2-carboxyphenyl; with the proviso that, when R.sup.3 is unsubstituted phenyl or 2-carboxyphenyl, R.sup.1 may not be unsubstituted phenyl.

Removal of interfering reducing substances with tetrazolium salts in

The present invention provides a process for the determination of iron in body fluids by liberation of the bound iron, reduction to Fe.sup.2+, addition of a color system appropriate for the detection of iron and photometric measurement in a tenside-containing sample solution, wherein a fatty acid polyethylene glycol ester, an alkanol polyglycol ether and at least 1 mole/liter quanidine hydrochloride are added to the sample solution. The present invention also provides a reagent for the determination of iron in serum, containing a reducing agent, a color material system appropriate for the detection of iron and guanidine hydrochloride and at least one tenside, wherein it contains a fatty acid polyethylene glycol ester and a alkanol polyglycol ether.

Method for determining iron in a body fluid sample

A water-soluble peroxidase derivative obtainable by the oxidation of peroxidase with periodic acid or with a salt thereof and binding to a water-soluble polymer selected from polysaccharides, polyethylene glycols, polyvinylpyrrolidones and polyacid anhydrides. Also provided is a process for the preparation of this water-soluble peroxidase derivative and for the use of this water-soluble peroxidase derivative for the determination of hydrogen peroxide.

Water-soluble peroxidase derivatives

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Oberhausen, Germany

Michael-Harold Town