Study of sintering characteristics using an improved method for the determination of the oxygen content in YBa2Cu3O7−δ

Improved method for the determination of the oxygen content in YBa2Cu3O7 –δ

Journal of Materials Chemistry ◽

10.1039/jm9910100863 ◽

1991 ◽

Vol 1 (5) ◽

pp. 863-866 ◽

Cited By ~ 12

Author(s):

Hilde Vlaeminck ◽

Hans H. Goossens ◽

Roland Mouton ◽

Serge Hoste ◽

Gustaaf Van der Kelen

Keyword(s):

Oxygen Content ◽

Improved Method

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SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

Acta Endocrinologica ◽

10.1530/acta.0.0720714 ◽

1973 ◽

Vol 72 (4) ◽

pp. 714-726 ◽

Cited By ~ 3

Author(s):

A. Burger ◽

B. Miller ◽

C. Sakoloff ◽

M. B. Vallotton

Keyword(s):

Ionic Strength ◽

Limit Of Detection ◽

Improved Method ◽

Accuracy Of Measurement ◽

Tracer Amount ◽

The Mean ◽

Physiological Values ◽

Hyperthyroid Patients ◽

Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

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