Biomaterial Database

Measurement of serum magnesium with a centrifugal analyzer. 1977

H Khayam-Bashi, and T Z Liu, and V Walter

We show how serum magnesium can be determined with a centrifugal analyzer. The method is based upon a manual procedure involving magnesium/calmagite complex formation in an alkaline reagent mixture. The assay, performed at 30 degrees C, requires 5 mul of serum in a final reaction volume of 405 mul, including 350 mul of reagent mixture. The stable color produced at 1 min is measured at 520 nm. Linearity studies showed that Beer's law was followed to 50 mg/liter. Average analytical recovery was 97.3%. Within-day studies showed CV's of 3.36% and 1.09%, compared to day-to-day variations of 5.32% and 3.04% at 18.8 and 46.6 mg of magnesium per liter, respectively. Correlation studies with the manual method, the Du Pont aca (methylthymol blue compleximetric) procedure, and atomic absorption spectroscopy showed correlation coefficients of 0.996, 0.976, and 0.950, respectively. Results compare excellently with those by common present methods. The method is fast, economical, reliable, and applicable to small specimen volumes.

UI	MeSH Term	Description	Entries
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D009282	Naphthalenesulfonates	A class of organic compounds that contains a naphthalene moiety linked to a sulfonic acid salt or ester.
D002498	Centrifugation	Process of using a rotating machine to generate centrifugal force to separate substances of different densities, remove moisture, or simulate gravitational effects. It employs a large motor-driven apparatus with a long arm, at the end of which human and animal subjects, biological specimens, or equipment can be revolved and rotated at various speeds to study gravitational effects. (From Websters, 10th ed; McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D001391	Azo Compounds	Organic chemicals where aryl or alkyl groups are joined by two nitrogen atoms through a double bond (R-N	Azo Dye,Azo Dyes,Compounds, Azo,Dye, Azo,Dyes, Azo
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.
D014050	Toluene	A widely used industrial solvent.