Determination of trace level iodine in biological and botanical reference materials by isotope dilution mass spectrometry

Determination of Trace Level Iodine in Biological and Botanical Reference Materials by Isotope Dilution Mass Spectrometry

A method has been developed for the determination of trace level iodine in biological and botanical materials. The method consists of spiking a sample with 129I, equilibration of the spike with the natural iodine, wet ashing under carefully controlled conditions, and separation of the iodine by co-precipitation with silver chloride. Measurement of the 129I/127I ratio is accomplished by negative...

Determination of selenium in biological materials by stable isotope dilution gas chromatography-mass spectrometry.

Determination of niacin in food materials by liquid chromatography using isotope dilution mass spectrometry.

The availability of deuterium-labeled nicotinic acid makes stable isotope dilution mass spectromerty (MS) coupled with liquid chromatography (LC) an attractive option for the determination of the water-soluble B-vitamin niacin in food samples. A method was developed based on acid digestion, solid-phase extraction with a strong cation exchange column, and reversed-phase chromatography with a C18...

Mass Spectrometry Inorganic Trace Analysis by Isotope Dilution Mass Spectrometry-New Frontiers

Isotope dilution mass spectrometry (IDMS) is used extensively at NBS in the certification of elemental concentrations in Standard Reference Materials. It is regarded at NBS as a "definitive method," that is, a method of proven high accuracy. Since the theme of this symposium is accuracy in trace element analysis, it is appropriate to review the role IDMS plays in accurate inorganic analysis. Th...

Direct determination of urinary iodine by inductively coupled plasma mass spectrometry using isotope dilution with iodine-129.

An inductively coupled mass spectrometric method was developed for the direct determination of iodine in urine. The application of isotope dilution analysis with added 129I offers new possibilities for automatic and accurate determinations. The sample preparation consists of dilution with an ammonia solution containing 129I. The validation was made by comparison with the results obtained in ano...