Kosaka Taeko, Hamada Hirohiko
Miyazaki Prefecture Institute for Public Health and Environment: 2-3-2, Nishi, Gakuen-kibanadai, Miyazaki 889-2155, Japan.
Shokuhin Eiseigaku Zasshi. 2002 Aug;43(4):225-9. doi: 10.3358/shokueishi.43.225.
A method was developed for analysis of thyroid hormones, 3,5,3'-triiodo-L-thyronine (T3) and L-thyroxine (T4), in health foods by liquid chromatography-electrospray ionization-mass spectrometry (LC/ESI-MS). In order to release T3 and T4 from thyroglobulin, samples were first hydrolyzed enzymatically using protease at a temperature of 37 +/- 1 degrees C for 28 h. The T3 and T4 were extracted with ethyl acetate and then the ethyl acetate layer was evaporated. The residue was dissolved in the mobile phase and analyzed by LC/MS. The LC separation was carried out on a ODS-3 column (2.1 x 150 mm) using H2O/CH3CN/CH3COOH (650/350/5) as the mobile phase. LC/ESI-MS was performed in the selected ion monitoring (SIM) mode using [M + H]+ ions at m/z 652 for T3 and m/z 778 for T4. The detection limit of both T3 and T4 released from thyroglobulin was 0.1 microgram/g in health foods. The present method was applied to analysis of three health foods which were labeled as foods for dieting. T3 and T4 were detected in two of the samples, and their contents were 16 and 29 micrograms/g and 31 and 90 micrograms/g, respectively.
建立了一种采用液相色谱 - 电喷雾电离 - 质谱法（LC/ESI-MS）分析保健食品中甲状腺激素3,5,3'-三碘 - L - 甲状腺原氨酸（T3）和L - 甲状腺素（T4）的方法。为了从甲状腺球蛋白中释放出T3和T4，首先将样品在37±1℃下用蛋白酶进行酶解28小时。用乙酸乙酯萃取T3和T4，然后将乙酸乙酯层蒸发。残留物溶解在流动相中并通过LC/MS进行分析。LC分离在ODS - 3柱（2.1×150mm）上进行，使用H2O/CH3CN/CH3COOH（650/350/5）作为流动相。LC/ESI-MS在选择离子监测（SIM）模式下进行，T3使用m/z 652的[M + H]+离子，T4使用m/z 778的[M + H]+离子。从甲状腺球蛋白中释放出的T3和T4在保健食品中的检测限均为0.1微克/克。本方法应用于分析三种标记为减肥食品的保健食品。在其中两个样品中检测到了T3和T4，其含量分别为16和29微克/克以及31和90微克/克。
