Determination of thyroid hormones by solid-phase extraction using high performance liquid chromatograph/diode array detector/electro-spray ionization mass spectrometry in urine samples
Analytical Science and Technology / Analytical Science and Technology, (P)1225-0163; (E)2288-8985
2006, v.19 no.6, pp.519-528
&
(2006). Determination of thyroid hormones by solid-phase extraction using high performance liquid chromatograph/diode array detector/electro-spray ionization mass spectrometry in urine samples. , 19(6), 519-528.
Abstract
An analytical method for the determination of thyroid hormones in urine samples has been studied by using solid-phase extraction and high-performance liquid chromatography/diode array detector/electro-spray mass spectrometry. Seven thyroid hormones were successfully separated by gradient elution on the reverse phase Hypersil ODS column (4.6 mm I.D., 100 mm length, particle size $5{\mu}m$) with ammonium formate buffer and acetonitrile, and UV spectra and mass fragment could be confirmed. The extraction recoveries of thyroid hormones in the urine samples (pH 3) were in the range of 89.0-113.1% with solid-phase extraction by C18, followed by elution with 4 ml of methanol/ammonium hydroxide (9 : 1). The calibration curves showed good linearity with the correlation coefficients ($r^2$) varying from 0.992 to 0.998 and the detection limits of all analytes were obtained in the range of 2-4 ng/ml (3.8-13.0 pmol/ml).
- keywords
-
thyroid hormones,
HPLC/DAD/ESI-MS,
urine