3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
overlapping of T0 and L-MIT was observed. For this reason
MS/MS mode detection was tested for selective extraction
of the ion [M + H] + of To (m/z 274.1) against L-MIT (m/z
308.1) – Fig 3.
A similar chromatogram was obtained with HPLC-ICP-
MS, but limits of detection decreased drastically and the mixtures
of hormones were traced at 5 µg dm –3 (Fig. 4).
Fig. 2. Chromatogram of thyroid hormones with hPLC-
(PDA)uV
Fig. 3. Chromatogram of thyroid hormones with hPLC-MS/MS
M e t h o d s P e r f o r m a n c e
The method based on HPLC-(PDA)UV present a linear
range between 1 and 25 mg dm –3 , with detection limits
between 0.04 to 0.1 mg dm –3 .
For the HPLC-ICP-MS method the linear range was
obtained between the detection limit and 100 µg dm –3 , and
detection limits between 0.15 and 2.0 µg dm –3 , depending of
compound considered.
s646
Fig. 4. Chromatogram of thyroid hormones with hPLC-ICP-MS
H o r m o n e s E x t r a c t i o n f r o m S e r u m
Proteins present in the serum were eliminated by precipitation
with 1 % of formic acid in acetonitrile.
The final approach were appplied to a control human
serum (ClinChek ® -Control serum), usually used in the hospital
for quality control, with good recoveries.
C o n c l u s i o n s
The combination of HPLC-PDA-UV-MS and HPLC-
ICP-MS allows identification and cuantification of thyroid
hormones in human serum. The use t-BuCQn colunm allows
chiral speciation of these hormones. Proteins elimination
from serum is necessary for the analysis of thyroid hormones
in human serum. The method is suitable for the analysis of
these hormones in control serum samples. Further studies are
necessary to check the applicability of the approach to real
human serum.
This work has been supported by the Grant CTM2006-
08960-C02-01(Ministerio de Educación y Ciencia-Spain
and project FQM-348 from the Consejería de Innovación,
Ciencia y Empresa (Junta de Andalucía)
REFEREnCES
1. Gorman C. A., Jiang n. S., Elldfson R. D., Elveback L.
R.: J.Clin. Endocrinol. Metab. 49, 1 (1979).
2. Eisdorfer I. B., Post A., J. Pharm. Sci. 56, 1092 (1967).
3. Simon R., Tietge J. E., Michalke B., Degitz S., Schramm
K. W.: Anal. Bioanal. Chem. 372, 481 (2002).