ABSTRACT
A mineralization and determination method for total iodine in nutritional and biological samples is described. Combustion of the sample in an oxygen stream is followed by collection of the combustion products in a 5% water-soluble tertiary amine solution. Iodine is determined by inductively coupled plasma mass spectrometry. The accuracy and precision of the quantitative iodine analysis using standard addition is better than +/- 10%. A semi-quantitative analysis of four standard reference materials is evaluated. Owing to the presence of low-level iodine contaminant in the blank solution, the determination limit of the method is +/- 10 micrograms kg-1. Good agreement with certified iodine values is obtained for six reference materials. The use of the tertiary amine matrix solution permits the simultaneous determination of iodine and other trace metals of biological and toxicological importance, including Mn, Co, Ni, Cu, Zn, Rb, Cd, and Pb.
Subject(s)
Iodine/analysis , Mass Spectrometry/methods , Trace Elements/analysis , Amines , Animals , Eggs/analysis , Iodine/standards , Solanum lycopersicum , Milk/chemistry , Ostreidae/chemistry , Oxygen , Plant Leaves/chemistry , Reference Standards , Reproducibility of Results , Shellfish , Trace Elements/standardsABSTRACT
This vapour-phase acid decomposition of small biological samples (50-165 mg) and concurrent purification of the reagent acid were achieved in a mini-quartz sample holder inserted in a commercial high-pressure digestion vessel. A 3.1 ml volume sample contained was developed to hold the sample and to maximize the successful decomposition of a variety of biological samples. When biological standard reference materials were digested at 230 degrees C and 122 bar (1770 psi), the residual carbon content in the digested samples was less than 1.8 +/- 0.1%. Inductively coupled plasma atomic emission spectrometric analysis of the digested materials for C, Ca, Cu, Cd, Fe, Mg, Mn and Zn provided good recoveries and low reagent blank values and demonstrated complete matrix decomposition.
Subject(s)
Metals/analysis , Animals , Cattle , Food Analysis , Horses , Humans , Metals/blood , Nephropidae , Ostreidae/chemistry , Spectrophotometry, AtomicABSTRACT
A rapid and accurate method for the inductively coupled plasma atomic emission spectrometric determination of Al, Ba, Si, Sr and Ti in food was developed based on a direct lithium metaborate fusion without sample pre-ashing. Six NIST diet test samples were analysed. Three independent sample preparation procedures were compared for verification.
