A phenomenon is described whereby iodine was shown to be adsorbed from aqueous standards by precipitated protein, to be subsequently ‘leached-off’ this protein by the first serum sample. The excessive protein precipitation was thought to be due to the water as supplied by a mixed-bed automatic deioniser.
A simple method for detecting this phenomenon is to follow the range of aqueous standards with three identical serum samples. It is probable that the sensitivity of the standard curve is diminished due to the phenomenon described if the first of the replicate samples has a peak height greater than the subsequent samples.
References
1.
RileyM.GochmanN. A fully automatic method for the determination of protein-bound iodine. Clin. Chem.10 (1954) 649.
2.
SearcyR. L.Diagnostic Biochemistry, McGraw-Hill, New York, 1969, p. 501.
