A micromethod for quantitative determination of iodoamino acids in thyroglobulin.
We describe a new method for quantification of iodoamino acids after enzymatic hydrolysis of thyroglobulin. The procedure involves separation of monoiodotyrosine (MIT), di-iodotyrosine, tri-iodothyronine and thyroxine by reverse phase HPLC with a Vydac C18 stationary phase and a mobile phase of water-acetonitrile-acetic acid. The separation is monitored by sensitive spectrophotometric detection through a 96-well microplate system based on the catalytic Sandell-Kolthoff reaction of iodide on the oxidation of arsenic(III) by cerium(IV). This new microassay is particularly convenient because of its high sensitivity and its rapidity (less than 2 h). It can detect 1 pmol MIT and 0.5 pmol of the other three iodoamino acids with a recovery higher than 96%. Moreover, the 96-well microplate system allows many samples to be tested simultaneously and avoids the use of radiolabeled iodine.
Baudry
N
N
Unité 38 INSERM, Faculté de Médicine, Marseille, France.
Mallet
B
B
Lejeune
P J
PJ
Vinet
L
L
Franc
J L
JL
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004105:Diiodotyrosine / Q000032:analysis; D007470:Monoiodotyrosine / Q000032:analysis; D013552:Swine; D013954:Thyroglobulin / Q000737:chemistry*; D013963:Thyroid Hormones / Q000032:analysis*; D013974:Thyroxine / Q000032:analysis; D014284:Triiodothyronine / Q000032:analysis
D013963:Thyroid Hormones; D014284:Triiodothyronine; D004105:Diiodotyrosine; D013954:Thyroglobulin; D007470:Monoiodotyrosine; D013974:Thyroxine